ISO 16000-3:2011
(Main)Indoor air — Part 3: Determination of formaldehyde and other carbonyl compounds in indoor air and test chamber air — Active sampling method
Indoor air — Part 3: Determination of formaldehyde and other carbonyl compounds in indoor air and test chamber air — Active sampling method
This part of ISO 16000 specifies a determination of formaldehyde (HCHO) and other carbonyl compounds (aldehydes and ketones) in air. The method is specific to formaldehyde but, with modification, at least 12 other aromatic as well as saturated and unsaturated aliphatic carbonyl compounds (see last paragraph) can be detected and quantified. It is suitable for determination of formaldehyde and other carbonyl compounds in the approximate concentration range 1 µg/m3 to 1 mg/m3. The sampling method gives a time-weighted average (TWA) sample. It can be used for long-term (1 h to 24 h) or short-term (5 min to 60 min) sampling of air for formaldehyde. This part of ISO 16000 specifies a sampling and analysis procedure for formaldehyde and other carbonyl compounds that involves collection from air on to adsorbent cartridges coated with 2,4-dinitrophenylhydrazine (DNPH) and subsequent analysis of the hydrazones formed by high performance liquid chromatography (HPLC) with detection by ultraviolet absorption. This part of ISO 16000 applies to the determination of: formaldehyde; acetaldehyde; acetone; benzaldehyde; butyraldehyde; valeraldehyde; 2,5-dimethylbenzaldehyde; capronaldehyde; isovaleraldehyde; propionaldehyde; o-tolualdehyde; m-tolualdehyde; p-tolualdehyde.
Air intérieur — Partie 3: Dosage du formaldéhyde et d'autres composés carbonylés dans l'air intérieur et dans l'air des chambres d'essai — Méthode par échantillonnage actif
L'ISO 16000-3:2011 spécifie un dosage du formaldéhyde (HCHO) et d'autres composés carbonylés (aldéhydes et cétones) dans l'air. La méthode est spécifique au formaldéhyde. Toutefois, si elle est modifiée, au moins 12 autres composés carbonylés (voir dernier alinéa) peuvent être détectés et quantifiés. Elle convient au dosage du formaldéhyde et d'autres composés carbonylés dans la plage de concentration comprise entre environ 1 µg/m3 et 1 mg/m3. La méthode d'échantillonnage fournit un résultat moyen pondéré dans le temps (TWA). Elle peut être utilisée pour l'échantillonnage du formaldéhyde dans l'air à long terme (1 h à 24 h) ou à court terme (5 min à 60 min). L'ISO 16000-3:2011 spécifie un mode opératoire d'échantillonnage et d'analyse pour le formaldéhyde et d'autres composés carbonylés qui implique un prélèvement de l'air sur des cartouches imprégnées de 2,4-dinitrophénylhydrazine (DNPH) et une analyse ultérieure par chromatographie en phase liquide à haute performance (CLHP) avec détection par absorption ultraviolette. L'ISO 16000-3:2011 est applicable au dosage des composés suivants: formaldéhyde, acétaldéhyde, acétone, benzaldéhyde, butyraldéhyde, valéraldéhyde, 2,5-diméthylbenzaldéhyde, capronaldéhyde, isovaléraldéhyde, propionaldéhyde, o-tolualdéhyde, m-tolualdéhyde, p-tolualdéhyde.
Notranji zrak - 3. del: Določevanje formaldehida in drugih karbonilnih spojin v notranjem zraku in zraku v preskusnih komorah - Metoda aktivnega vzorčenja
Ta del standarda ISO 16000 določa ugotavljanje formaldehida (HCHO) in drugih karbonilnih spojin (aldehidov in ketonov) v zraku. Metoda je specifična za formaldehid, vendar se lahko s spremembami uporablja za določevanje in kvantifikacijo najmanj 12 drugih aromatskih, nasičenih in nenasičenih alifatskih karbonilnih spojin. Primerna je za določevanje formaldehida in drugih karbonilnih spojin v približnem območju koncentracije od 1 μg/m3 do 1 mg/m3. Metoda vzorčenja podaja časovno tehtani povprečni (TWA) vzorec. Uporablja se lahko za dolgoročno (od 1 do 24 h) ali kratkoročno (od 5 do 60 min) vzorčenje zraka za formaldehid. Ta del standarda ISO 16000 določa postopek za vzorčenje in analizo formaldehida in drugih karbonilnih spojin, ki vključuje zbiranje iz zraka v kasete za adsorpcijo, prevlečene z 2,4-dinitrofenilhidrazinom (DNPH), ter poznejšo analizo hidrazonov, nastalih s tekočinsko kromatografijo visoke ločljivosti (HPLC), z zaznavanjem prek ultravijolične absorpcije[12],[16]. Metoda ni ustrezna za daljše verižne ali nenasičene karbonilne spojine.
General Information
Relations
Buy Standard
Standards Content (Sample)
SLOVENSKI STANDARD
SIST ISO 16000-3:2012
01-april-2012
1DGRPHãþD
SIST ISO 16000-3:2002
1RWUDQML]UDNGHO 'RORþHYDQMHIRUPDOGHKLGDLQGUXJLKNDUERQLOQLKVSRMLQY
QRWUDQMHP]UDNXLQ]UDNXYSUHVNXVQLKNRPRUDK0HWRGDDNWLYQHJDY]RUþHQMD
Indoor air - Part 3: Determination of formaldehyde and other carbonyl compounds in
indoor air and test chamber air - Active sampling method
Air intérieur - Partie 3: Dosage du formaldéhyde et d'autres composés carbonylés dans
l'air intérieur et dans l'air des chambres d'essai - Méthode par échantillonnage actif
Ta slovenski standard je istoveten z: ISO 16000-3:2011
ICS:
13.040.20 Kakovost okoljskega zraka Ambient atmospheres
SIST ISO 16000-3:2012 en,fr
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
SIST ISO 16000-3:2012
---------------------- Page: 2 ----------------------
SIST ISO 16000-3:2012
INTERNATIONAL ISO
STANDARD 16000-3
Second edition
2011-10-15
Indoor air —
Part 3:
Determination of formaldehyde and other
carbonyl compounds in indoor air and
test chamber air — Active sampling
method
Air intérieur —
Partie 3: Dosage du formaldéhyde et d'autres composés carbonylés
dans l'air intérieur et dans l'air des chambres d'essai — Méthode par
échantillonnage actif
Reference number
ISO 16000-3:2011(E)
©
ISO 2011
---------------------- Page: 3 ----------------------
SIST ISO 16000-3:2012
ISO 16000-3:2011(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2011
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2011 – All rights reserved
---------------------- Page: 4 ----------------------
SIST ISO 16000-3:2012
ISO 16000-3:2011(E)
Contents Page
Foreword . iv
Introduction . vi
1 Scope . 1
2 Normative references . 2
3 Principle . 2
4 Limitations and interferences . 2
5 Safety measures . 3
6 Apparatus . 4
7 Reagents and materials . 7
8 Preparation of reagents and cartridges . 7
9 Procedure . 10
10 Calculations . 19
11 Performance criteria and quality assurance . 20
12 Precision and uncertainty . 22
13 Test report . 22
Annex A (informative) Precision and uncertainty . 23
Annex B (informative) Melting points of DNPH-carbonyl derivatives . 25
Bibliography . 26
© ISO 2011 – All rights reserved iii
---------------------- Page: 5 ----------------------
SIST ISO 16000-3:2012
ISO 16000-3:2011(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 16000-3 was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 6, Indoor air.
This second edition cancels and replaces the first edition (ISO 16000-3:2001), which has been technically
revised.
ISO 16000 consists of the following parts, under the general title Indoor air:
Part 1: General aspects of sampling strategy
Part 2: Sampling strategy for formaldehyde
Part 3: Determination of formaldehyde and other carbonyl compounds in indoor air and test chamber
air — Active sampling method
Part 4: Determination of formaldehyde — Diffusive sampling method
Part 5: Sampling strategy for volatile organic compounds (VOCs)
Part 6: Determination of volatile organic compounds in indoor and test chamber air by active sampling on
®
Tenax TA sorbent, thermal desorption and gas chromatography using MS or MS-FID
Part 7: Sampling strategy for determination of airborne asbestos fibre concentrations
Part 8: Determination of local mean ages of air in buildings for characterizing ventilation conditions
Part 9: Determination of the emission of volatile organic compounds from building products and
furnishing — Emission test chamber method
Part 10: Determination of the emission of volatile organic compounds from building products and
furnishing — Emission test cell method
Part 11: Determination of the emission of volatile organic compounds from building products and
furnishing — Sampling, storage of samples and preparation of test specimens
Part 12: Sampling strategy for polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins
(PCDDs), polychlorinated dibenzofurans (PCDFs) and polycyclic aromatic hydrocarbons (PAHs)
iv © ISO 2011 – All rights reserved
---------------------- Page: 6 ----------------------
SIST ISO 16000-3:2012
ISO 16000-3:2011(E)
Part 13: Determination of total (gas and particle-phase) polychlorinated dioxin-like biphenyls (PCBs) and
polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDDs/PCDFs) — Collection on sorbent-backed filters
Part 14: Determination of total (gas and particle-phase) polychlorinated dioxin-like biphenyls (PCBs) and
polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDDs/PCDFs) — Extraction, clean-up and analysis by
high-resolution gas chromatography and mass spectrometry
Part 15: Sampling strategy for nitrogen dioxide (NO )
2
Part 16: Detection and enumeration of moulds — Sampling by filtration
Part 17: Detection and enumeration of moulds — Culture-based method
Part 18: Detection and enumeration of moulds — Sampling by impaction
Part 19: Sampling strategy for moulds
Part 23: Performance test for evaluating the reduction of formaldehyde concentrations by sorptive
building materials
Part 24: Performance test for evaluating the reduction of volatile organic compound (except
formaldehyde) concentrations by sorptive building materials
Part 25: Determination of the emission of semi-volatile organic compounds by building products — Micro-
chamber method
Part 26: Sampling strategy for carbon dioxide (CO )
2
Part 28: Determination of odour emissions from building products using test chambers
The following parts are under preparation:
Part 21: Detection and enumeration of moulds — Sampling from materials
Part 27: Determination of settled fibrous dust on surfaces by SEM (scanning electron microscopy) (direct
method)
Part 29: Test methods for VOC detectors
Part 30: Sensory testing of indoor air
Part 31: Measurement of flame retardants and plasticizers based on organophosphorus compounds —
Phosphoric acid ester
Part 32: Investigation of constructions on pollutants and other injurious factors — Inspections
© ISO 2011 – All rights reserved v
---------------------- Page: 7 ----------------------
SIST ISO 16000-3:2012
ISO 16000-3:2011(E)
Introduction
This part of ISO 16000 is intended to be used for characterizing indoor air following the sampling strategy
specified in ISO 16000-2. It is applicable to formaldehyde and other carbonyl compounds. It has been tested
for 14 aldehydes and ketones. Formaldehyde is the simplest carbonyl compound, with one carbon, one
oxygen and two hydrogen atoms. In its monomolecular state, it is a colourless, pungent, reactive gas. It has
been used in the production of urea-formaldehyde resins, adhesives, and insulating foams. Emissions from
particle (chip) board and wall insulation are the major sources of formaldehyde in indoor air.
Formaldehyde is collected by passing air through a reactive medium that converts the compound to a
derivative of lower vapour pressure that is more efficiently retained by the sampler and can be easily analysed.
This part of ISO 16000 determines formaldehyde and other carbonyl compounds by reaction with
2,4-dinitrophenylhydrazine coated on to a sorbent to convert them to their corresponding hydrazones, which
can be recovered and measured with high sensitivity, precision, and accuracy. Other carbonyl compounds
that may be emitted into air from solvents, adhesives, cosmetics, and other sources can also be determined
using this part of ISO 16000.
[12]
The sampling procedure is based on US EPA method TO-11A .
[15]
Formaldehyde and certain other carbonyl compounds have a high toxic potential .
[7][8] [2]–[6]
ISO 16017 and ISO 12219 also focus on volatile organic compound (VOC) measurements.
vi © ISO 2011 – All rights reserved
---------------------- Page: 8 ----------------------
SIST ISO 16000-3:2012
INTERNATIONAL STANDARD ISO 16000-3:2011(E)
Indoor air —
Part 3:
Determination of formaldehyde and other carbonyl compounds
in indoor air and test chamber air — Active sampling method
WARNING — Persons using this part of ISO 16000 should be familiar with normal laboratory practice.
This part of ISO 16000 does not purport to address all of the safety problems, if any, associated with
its use. It is the responsibility of the user to establish appropriate safety and health practices and to
ensure compliance with any national regulatory conditions.
1 Scope
This part of ISO 16000 specifies a determination of formaldehyde (HCHO) and other carbonyl compounds
1
(aldehydes and ketones) in air. The method is specific to formaldehyde but, with modification, at least
12 other aromatic as well as saturated and unsaturated aliphatic carbonyl compounds can be detected and
quantified. It is suitable for determination of formaldehyde and other carbonyl compounds in the approximate
3 3
concentration range 1 µg/m to 1 mg/m . The sampling method gives a time-weighted average (TWA) sample.
It can be used for long-term (1 h to 24 h) or short-term (5 min to 60 min) sampling of air for formaldehyde.
This part of ISO 16000 specifies a sampling and analysis procedure for formaldehyde and other carbonyl
compounds that involves collection from air on to adsorbent cartridges coated with 2,4-dinitrophenylhydrazine
(DNPH) and subsequent analysis of the hydrazones formed by high performance liquid chromatography
[12],[16]
(HPLC) with detection by ultraviolet absorption . The method is not suitable for longer chained or
unsaturated carbonyl compounds.
This part of ISO 16000 applies to the determination of:
acetaldehyde 2,5-dimethylbenzaldehyde m -tolualdehyde
acetone formaldehyde o -tolualdehyde
benzaldehyde isovaleraldehyde p -tolualdehyde
butyraldehyde propionaldehyde valeraldehyde
capronaldehyde
1 Instead of systematic IUPAC nomenclature, traditional names are used in this part of ISO 16000. Some equivalent
names are:
acetaldehyde: ethanal formaldehyde: methanal o -tolualdehyde: 2-methylbenzaldehyde
acetone: 2-propanone isovaleraldehyde: 3-methylbutanal p -tolualdehyde: 4-methylbenzaldehyde
butyraldehyde: butanal propionaldehyde: propanal valeraldehyde: pentanal
capronaldehyde: hexanal m -tolualdehyde: 3-methylbenzaldehyde
© ISO 2011 – All rights reserved 1
---------------------- Page: 9 ----------------------
SIST ISO 16000-3:2012
ISO 16000-3:2011(E)
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories
3 Principle
The method specified in this part of ISO 16000 involves drawing air through a cartridge containing silica gel
coated with 2,4-dinitrophenylhydrazine (DNPH) reagent. The principle of the method is based on the specific
reaction of a carbonyl group with DNPH in the presence of an acid to form stable derivatives according to the
reaction shown in Figure 1. The DNPH derivatives are analysed for the parent aldehydes and ketones utilizing
high performance liquid chromatography (HPLC) with UV detection or diode array detection. The detection
has been extended to other carbonyl compounds that can be determined as outlined in 9.3.5.
This part of ISO 16000 instructs the user on how to prepare sampling cartridges from commercially available
chromatographic grade silica gel cartridges by the application of acidified DNPH to each cartridge.
Alternatively, pre-coated DNPH silica gel cartridges are available and are recommended since they are
generally more uniform in manufacture and possess lower blank levels. However, if commercial cartridges are
used, they shall be demonstrated to meet the performance criteria of this part of ISO 16000. Another
advantage of commercial cartridges is that they are available with larger particle size silica gel that results in a
lower pressure drop across the cartridge. These low pressure drop cartridges may be more suitable for
sampling air using battery-powered personal sampling pumps.
Carbonyl compound 2,4-Dinitrophenylhydrazine DNPH derivative
(aldehyde or ketone) (DNPH)
Key
R, R′ H, alkyl group, aromatic group
Figure 1 — Reaction of carbonyl compounds to form 2,4-dinitrophenylhydrazones
4 Limitations and interferences
4.1 General
The sampling flow rate specified in this part of ISO 16000 has been validated for sampling rates up to
1,5 l/min. This flow rate limitation is principally due to the high pressure drop (>8 kPa at 1,0 l/min) across the
user-prepared silica gel cartridges, which have particle sizes of 55 µm to 105 µm. These cartridges are not
generally compatible with battery-powered pumps used in personal sampling equipment (e.g. those used by
industrial hygienists).
The solid-sorbent sampling procedure is specific for sampling and analysis of formaldehyde. Interferences in
this method are caused by certain isomeric aldehydes or ketones that may be unresolved by the HPLC
system when analysing for other aldehydes and ketones. Any organic compounds that have the same
retention times and significant absorbance at 360 nm as the DNPH derivative of formaldehyde interfere. Such
interferences can often be overcome by altering the separation conditions (e.g. using alternative HPLC
columns or mobile phase compositions).
2 © ISO 2011 – All rights reserved
---------------------- Page: 10 ----------------------
SIST ISO 16000-3:2012
ISO 16000-3:2011(E)
Formaldehyde contamination of the DNPH reagent is a frequently encountered problem. The DNPH shall be
purified by multiple recrystallizations in UV-grade acetonitrile (ACN). Recrystallization is accomplished, at
40 °C to 60 °C, by slow evaporation of the solvent to maximize crystal size. Impurity levels of carbonyl
compounds in the DNPH are determined prior to use by HPLC and should be less than 0,15 µg per cartridge.
Exposure of the DNPH-coated sampling cartridges to direct sunlight may produce artefacts and should be
[17]
avoided .
Acrolein and crotonaldehyde may not be accurately quantified by the method. Inaccurate results for these
[18]
compounds may result from the formation of multiple derivative peaks and the instability of the peak ratios .
Nitrogen dioxide reacts with DNPH. High concentrations of NO (e.g. for gas cooking stoves) may cause
2
problems as the retention time of the DNPH derivative may be similar to that of the DNPH formaldehyde
[13][14][19]
derivative, depending on the HPLC column and the parameters .
4.2 Ozone interference
If there is suspicion that abnormally high levels of ozone are present in the area being sampled (e.g. from
office copiers), special care should be exercised. Ozone has been shown to interfere negatively by reacting
[20]
with both DNPH and its derivatives (hydrazones) in the cartridge . The extent of interference depends on
the temporal variations of both the ozone and the carbonyl compounds and the duration of sampling.
Significant negative interference from ozone has been observed even at concentrations of formaldehyde and
[19]
3 3
ozone typical of clean ambient air (2 µg/m and 80 µg/m , respectively) . The presence of ozone in the
sample is readily inferred upon analysis by the appearance of new compounds with retention times shorter
than that of the hydrazone of formaldehyde. Figure 2 shows chromatograms of samples of a formaldehyde-
spiked air stream with and without ozone.
The most direct solution to ozone interference is to remove the ozone before the sampled air reaches the
cartridge. This can be accomplished by the use of an ozone denuder or scrubber placed in front of the
cartridge. Both ozone denuders and scrubber cartridges are commercially available. A denuder may be
constructed of 1 m of copper tubing of outside diameter 0,64 cm and of inside diameter 0,46 cm, that is filled
with a saturated solution of potassium iodide in water, allowed to stand for a few minutes (e.g. 5 min), drained
and dried with a stream of clean air or nitrogen for about 1 h. The capacity of the ozone denuder as specified
3
is about 200 µg/m h. Test aldehydes (formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde and
p-tolualdehyde) that were dynamically spiked into an ambient sample air stream passed through the ozone
[21]
denuder with practically no losses . Commercial ozone scrubbers made from a cartridge filled with 300 mg
[22]
to 500 mg of granular potassium iodide have also been found to be effective in removing ozone .
5 Safety measures
5.1 2,4-Dinitrophenylhydrazine is explosive in the dry state and shall be handled with extreme care. It is
also toxic (in the rat, LD = 654 mg/kg), has been shown to be mutagenic in some tests, and is irritating to the
50
eyes and skin.
5.2 Perchloric acid at concentrations less than 68 % mass fraction is stable and non-oxidizing at room
temperature. However, it is readily dehydrated at temperatures above 160 °C and can cause explosions on
contact with alcohols, wood, cellulose, and other oxidizable materials. It should be stored in a cool, dry place
and used only in a chemical fume hood with caution.
© ISO 2011 – All rights reserved 3
---------------------- Page: 11 ----------------------
SIST ISO 16000-3:2012
ISO 16000-3:2011(E)
Key
A relative absorbance 1 unknown
t time 2 DNPH
A with ozone 3 formaldehyde
B without ozone 4 acetaldehyde
Figure 2 — Cartridge samples of formaldehyde in an air stream with and without ozone
6 Apparatus
Usual laboratory apparatus and in particular the following.
6.1 Sampling
6.1.1 Sampling cartridge, packed with silica gel and coated with DNPH in accordance with Clause 8, or as
available commercially.
The cartridge shall contain a minimum quantity of 350 mg of silica gel with a minimum DNPH loading of
0,29 % mass fraction. The ratio of the silica gel bed diameter to bed length shall not exceed 1:1. The capacity
of the cartridge for formaldehyde shall be at least 75 µg and the collection efficiency at least 95 % at a
sampling rate of 1,5 l/min. Sampling cartridges with very low blank levels and high performance are
commercially available.
NOTE A pressure drop through the user-prepared sample cartridge of about 19 kPa at a sampling rate of 1,5 l/min
has been observed. Some commercially available pre-coated cartridges exhibit lower pressure-drops, which permit the
use of battery-operated personal sampling pumps.
6.1.2 Air sampling pump, capable of accurately and precisely sampling at a flow rate of 0,1 l/min to
1,5 l/min.
6.1.3 Flow controller, mass flow meters and mass flow controllers, or other suitable device for metering
and setting air flow rates of 0,50 l/min to 1,20 l/min through the sample cartridge.
6.1.4 Flow calibrator, such as a rotameter, soap-bubble meter or wet test meter.
4 © ISO 2011 – All rights reserved
---------------------- Page: 12 ----------------------
SIST ISO 16000-3:2012
ISO 16000-3:2011(E)
6.2 Sample preparation
6.2.1 Cartridge containers, e.g. borosilicate glass culture tubes (20 mm ¥ 125 mm) with polypropylene
screw caps, or other suitable containers, to transport coated cartridges.
6.2.2 Polyethylene gloves, to handle silica gel cartridges.
6.2.3 Transportation containers, friction-top metal cans (e.g. of volume 4 l) or other suitable containers,
with polyethylene air-bubble packing or other suitable padding, to hold and cushion the sealed cartridge
containers.
NOTE A heat-sealable foil-lined plastic pouch of the type included with some commercial pre-coated DNPH
cartridges can be used for storing a DNPH-coated cartridge after sampling, if appropriate.
6.2.4 Support for coating cartridges. A syringe rack, made from an aluminium plate
(0,16 cm ¥ 36 cm ¥ 53 cm) with adjustable legs on four corners. A matrix (5 ¥ 9) of circular holes of diameter
slightly larger than the diameter of the 10 ml syringes, symmetrically drilled from the centre of the plate, to
enable batch processing of 45 cartridges for cleaning, coating and/or sample elution (see Figure 3).
6.2.5 Cartridge-drying manifold, such as a support with gas connectors and with multiple standard male
syringe connectors (see Figure 3).
NOTE The apparatus specified in 6.2.4 and 6.2.5 is needed only if users choose to make their own DNPH-coated
cartridges.
6.3 Sample analysis
6.3.1 HPLC system, consisting of:
a) a mobile phase reservoir with an outgassing device (e.g. membrane under reduced pressure);
b) a high-pressure pump;
c) an injection valve (automatic sampler with a 25 µl or other convenient loop volume);
d) a C-18 reverse phase (RP) column (e.g. 25 cm ¥ 4,6 mm inside diameter, 5 µm particle size);
e) a UV detector or diode array detector operating at 360 nm;
f) a data system or strip chart recorder.
The DNPH-formaldehyde derivative is determined using isocratic reverse phase HPLC, equipped with an
ultraviolet (UV) absorption detector operated at 360 nm. A blank cartridge is likewise desorbed and analysed.
Formaldehyde and other carbonyl compounds in the sample are identified and quantified by comparison of
their retention times and peak heights or peak areas with those of standard solutions.
NOTE 1 Most commercial HPLC analytical systems are adequate for this application.
NOTE 2 A column oven can be used to assure constant column operating temperature and improve reproducibility.
6.3.2 Syringes and pipettes
6.3.2.1 HPLC injection syringes, with capacity at least four times the loop volume (see 6.3.1).
6.3.2.2 Syringes, volume 10 ml, used to prepare DNPH-coated cartridges (polypropylene syringes are
adequate).
6.3.2.3 Syringe fittings and plugs, to connect cartridges to the sampling system and to cap prepared
cartridges.
6.3.2.4 Pipettes, positive-displacement, repetitive-dispensing type, with capacities in the 0 ml to 10 ml
[1]
range, ISO 8655-2 .
© ISO 2011 – All rights reserved 5
---------------------- Page: 13 ----------------------
SIST ISO 16000-3:2012
ISO 16000-3:2011(E)
a) Rack for coating cartridges
b) Rack for drying DNPH-coated cartridges
Key
1 10 ml glass syringes 5 N gas stream
2
2 test tube rack 6 syringe fitting
3 cartridges 7 waste vials
4 waste beakers
Figure 3 — Syringe rack for coating and drying sample cartridges
6 © ISO 2011 – All rights reserved
---------------------- Page: 14 ----------------------
SIST ISO 16000-3:2012
ISO 16000-3:2011(E)
7 Reagents and materials
During the analysis, unless otherwise stated, use only reagents of recognized analytical grade, e.g. best
quality grade, grade for chemical analysis or grade for HPLC analysis, and distilled or demineralized water or
water of equivalent purity.
7.1 2,4-Dinitrophenylhydrazine, recrystallized at least twice with UV-grade acetonitrile before use.
7.2 Acetonitrile, UV grade (each batch of solvent should be tested before use).
7.3 Perchloric acid, 60 % mass fraction, r = 1,51 kg/l, reagent grade (best source).
7.4 Hydrochloric acid, 36,5 % to 38 % mass fraction, r = 1,19 kg/l, reagent grade (best source).
7.5 Hydrochloric acid, 2 mol/l, reagent grade (best source).
7.6 Formaldehyde, 37 % mass fraction solution, reagent grade (best source).
7.7 Aldehydes and ketones, high purity, used for preparation of DNPH derivative standards (optional).
7.8 Ethanol or methanol, HPLC grade.
7.9 Nitrogen, high purity grade (best source).
7.10 Charcoal, granular (best source).
7.11 Helium, high purity grade (best source).
8 Preparation of reagents and cartridges
8.1 Purification of 2,4-dinitrophenylhydrazine
Formaldehyde contamination of the DNPH reagent is a frequently encountered problem. The DNPH (7.1) shall
be purified by multiple recrystallizations in UV-grade acetonitrile (7.2). Recrystallization is accomplished, at
40 °C to 60 °C, by slow evaporation of the solvent to maximize crystal size. Impurity levels of carbonyl
compounds in the DNPH are determined prior to use by HPLC and should be less than 0,15 µg per cartridge
and per individual compound.
Prepare a supersaturated solution of DNPH by boiling excess DNPH in 200 ml of acetonitrile for
approximately 1 h. After 1 h, remove and transfer the supernatant to a covered beaker on a hot plate and
allow gradual cooling to 40 °C to 60 °C. Maintain the solution at this temperature (40 °C) until 95 % volume
fraction of solvent has evaporated. Decant the solution to waste, and rinse the remaining crystals twice with
three times their apparent volume of acetonitrile. Transfer the crystals to another clean beaker, add 200 ml of
acetonitrile, heat to boiling, and again let crystals grow slowly at 40 °C to 60 °C until 95 % volume fraction of
the solvent has evaporated. Repeat the rinsing process as specified above. Take an aliquot of the second
rinse, dilute 10 times with acetonitrile, acidify with 1 ml of 3,8 mol/l perchloric acid (7.3) per 100 ml of DNPH
solution, and analyse by HPLC, in accordance with 9.3.4.
WARNING — Carry out this procedure under a properly ventilated hood and behind an explosion
shield.
NOTE An acid is necessary to catalyse the reaction of carbonyl compounds with DNPH. Most strong inorganic acids
such as hydrochloric, sulfuric, phosphoric or perchloric acids perform satisfactorily. In rare cases, hydrochloric and sulfuric
acids cause problems.
An acceptable impurity level is <0,025 µg/ml of formaldehyde hydrazone in recrystallized DNPH reagent or
0,02 % mass fraction of the DNPH.
© ISO 2011 – All rights reserved 7
---------------------- Page: 15 ----------------------
SIST ISO 16000-3:2012
ISO 16000-3:2011(E)
If the impurity level is not acceptable for the intended sampling application, repeat recrystalliza
...
INTERNATIONAL ISO
STANDARD 16000-3
Second edition
2011-10-15
Indoor air —
Part 3:
Determination of formaldehyde and other
carbonyl compounds in indoor air and
test chamber air — Active sampling
method
Air intérieur —
Partie 3: Dosage du formaldéhyde et d'autres composés carbonylés
dans l'air intérieur et dans l'air des chambres d'essai — Méthode par
échantillonnage actif
Reference number
ISO 16000-3:2011(E)
©
ISO 2011
---------------------- Page: 1 ----------------------
ISO 16000-3:2011(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2011
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2011 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 16000-3:2011(E)
Contents Page
Foreword . iv
Introduction . vi
1 Scope . 1
2 Normative references . 2
3 Principle . 2
4 Limitations and interferences . 2
5 Safety measures . 3
6 Apparatus . 4
7 Reagents and materials . 7
8 Preparation of reagents and cartridges . 7
9 Procedure . 10
10 Calculations . 19
11 Performance criteria and quality assurance . 20
12 Precision and uncertainty . 22
13 Test report . 22
Annex A (informative) Precision and uncertainty . 23
Annex B (informative) Melting points of DNPH-carbonyl derivatives . 25
Bibliography . 26
© ISO 2011 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO 16000-3:2011(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 16000-3 was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 6, Indoor air.
This second edition cancels and replaces the first edition (ISO 16000-3:2001), which has been technically
revised.
ISO 16000 consists of the following parts, under the general title Indoor air:
Part 1: General aspects of sampling strategy
Part 2: Sampling strategy for formaldehyde
Part 3: Determination of formaldehyde and other carbonyl compounds in indoor air and test chamber
air — Active sampling method
Part 4: Determination of formaldehyde — Diffusive sampling method
Part 5: Sampling strategy for volatile organic compounds (VOCs)
Part 6: Determination of volatile organic compounds in indoor and test chamber air by active sampling on
®
Tenax TA sorbent, thermal desorption and gas chromatography using MS or MS-FID
Part 7: Sampling strategy for determination of airborne asbestos fibre concentrations
Part 8: Determination of local mean ages of air in buildings for characterizing ventilation conditions
Part 9: Determination of the emission of volatile organic compounds from building products and
furnishing — Emission test chamber method
Part 10: Determination of the emission of volatile organic compounds from building products and
furnishing — Emission test cell method
Part 11: Determination of the emission of volatile organic compounds from building products and
furnishing — Sampling, storage of samples and preparation of test specimens
Part 12: Sampling strategy for polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins
(PCDDs), polychlorinated dibenzofurans (PCDFs) and polycyclic aromatic hydrocarbons (PAHs)
iv © ISO 2011 – All rights reserved
---------------------- Page: 4 ----------------------
ISO 16000-3:2011(E)
Part 13: Determination of total (gas and particle-phase) polychlorinated dioxin-like biphenyls (PCBs) and
polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDDs/PCDFs) — Collection on sorbent-backed filters
Part 14: Determination of total (gas and particle-phase) polychlorinated dioxin-like biphenyls (PCBs) and
polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDDs/PCDFs) — Extraction, clean-up and analysis by
high-resolution gas chromatography and mass spectrometry
Part 15: Sampling strategy for nitrogen dioxide (NO )
2
Part 16: Detection and enumeration of moulds — Sampling by filtration
Part 17: Detection and enumeration of moulds — Culture-based method
Part 18: Detection and enumeration of moulds — Sampling by impaction
Part 19: Sampling strategy for moulds
Part 23: Performance test for evaluating the reduction of formaldehyde concentrations by sorptive
building materials
Part 24: Performance test for evaluating the reduction of volatile organic compound (except
formaldehyde) concentrations by sorptive building materials
Part 25: Determination of the emission of semi-volatile organic compounds by building products — Micro-
chamber method
Part 26: Sampling strategy for carbon dioxide (CO )
2
Part 28: Determination of odour emissions from building products using test chambers
The following parts are under preparation:
Part 21: Detection and enumeration of moulds — Sampling from materials
Part 27: Determination of settled fibrous dust on surfaces by SEM (scanning electron microscopy) (direct
method)
Part 29: Test methods for VOC detectors
Part 30: Sensory testing of indoor air
Part 31: Measurement of flame retardants and plasticizers based on organophosphorus compounds —
Phosphoric acid ester
Part 32: Investigation of constructions on pollutants and other injurious factors — Inspections
© ISO 2011 – All rights reserved v
---------------------- Page: 5 ----------------------
ISO 16000-3:2011(E)
Introduction
This part of ISO 16000 is intended to be used for characterizing indoor air following the sampling strategy
specified in ISO 16000-2. It is applicable to formaldehyde and other carbonyl compounds. It has been tested
for 14 aldehydes and ketones. Formaldehyde is the simplest carbonyl compound, with one carbon, one
oxygen and two hydrogen atoms. In its monomolecular state, it is a colourless, pungent, reactive gas. It has
been used in the production of urea-formaldehyde resins, adhesives, and insulating foams. Emissions from
particle (chip) board and wall insulation are the major sources of formaldehyde in indoor air.
Formaldehyde is collected by passing air through a reactive medium that converts the compound to a
derivative of lower vapour pressure that is more efficiently retained by the sampler and can be easily analysed.
This part of ISO 16000 determines formaldehyde and other carbonyl compounds by reaction with
2,4-dinitrophenylhydrazine coated on to a sorbent to convert them to their corresponding hydrazones, which
can be recovered and measured with high sensitivity, precision, and accuracy. Other carbonyl compounds
that may be emitted into air from solvents, adhesives, cosmetics, and other sources can also be determined
using this part of ISO 16000.
[12]
The sampling procedure is based on US EPA method TO-11A .
[15]
Formaldehyde and certain other carbonyl compounds have a high toxic potential .
[7][8] [2]–[6]
ISO 16017 and ISO 12219 also focus on volatile organic compound (VOC) measurements.
vi © ISO 2011 – All rights reserved
---------------------- Page: 6 ----------------------
INTERNATIONAL STANDARD ISO 16000-3:2011(E)
Indoor air —
Part 3:
Determination of formaldehyde and other carbonyl compounds
in indoor air and test chamber air — Active sampling method
WARNING — Persons using this part of ISO 16000 should be familiar with normal laboratory practice.
This part of ISO 16000 does not purport to address all of the safety problems, if any, associated with
its use. It is the responsibility of the user to establish appropriate safety and health practices and to
ensure compliance with any national regulatory conditions.
1 Scope
This part of ISO 16000 specifies a determination of formaldehyde (HCHO) and other carbonyl compounds
1
(aldehydes and ketones) in air. The method is specific to formaldehyde but, with modification, at least
12 other aromatic as well as saturated and unsaturated aliphatic carbonyl compounds can be detected and
quantified. It is suitable for determination of formaldehyde and other carbonyl compounds in the approximate
3 3
concentration range 1 µg/m to 1 mg/m . The sampling method gives a time-weighted average (TWA) sample.
It can be used for long-term (1 h to 24 h) or short-term (5 min to 60 min) sampling of air for formaldehyde.
This part of ISO 16000 specifies a sampling and analysis procedure for formaldehyde and other carbonyl
compounds that involves collection from air on to adsorbent cartridges coated with 2,4-dinitrophenylhydrazine
(DNPH) and subsequent analysis of the hydrazones formed by high performance liquid chromatography
[12],[16]
(HPLC) with detection by ultraviolet absorption . The method is not suitable for longer chained or
unsaturated carbonyl compounds.
This part of ISO 16000 applies to the determination of:
acetaldehyde 2,5-dimethylbenzaldehyde m -tolualdehyde
acetone formaldehyde o -tolualdehyde
benzaldehyde isovaleraldehyde p -tolualdehyde
butyraldehyde propionaldehyde valeraldehyde
capronaldehyde
1 Instead of systematic IUPAC nomenclature, traditional names are used in this part of ISO 16000. Some equivalent
names are:
acetaldehyde: ethanal formaldehyde: methanal o -tolualdehyde: 2-methylbenzaldehyde
acetone: 2-propanone isovaleraldehyde: 3-methylbutanal p -tolualdehyde: 4-methylbenzaldehyde
butyraldehyde: butanal propionaldehyde: propanal valeraldehyde: pentanal
capronaldehyde: hexanal m -tolualdehyde: 3-methylbenzaldehyde
© ISO 2011 – All rights reserved 1
---------------------- Page: 7 ----------------------
ISO 16000-3:2011(E)
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories
3 Principle
The method specified in this part of ISO 16000 involves drawing air through a cartridge containing silica gel
coated with 2,4-dinitrophenylhydrazine (DNPH) reagent. The principle of the method is based on the specific
reaction of a carbonyl group with DNPH in the presence of an acid to form stable derivatives according to the
reaction shown in Figure 1. The DNPH derivatives are analysed for the parent aldehydes and ketones utilizing
high performance liquid chromatography (HPLC) with UV detection or diode array detection. The detection
has been extended to other carbonyl compounds that can be determined as outlined in 9.3.5.
This part of ISO 16000 instructs the user on how to prepare sampling cartridges from commercially available
chromatographic grade silica gel cartridges by the application of acidified DNPH to each cartridge.
Alternatively, pre-coated DNPH silica gel cartridges are available and are recommended since they are
generally more uniform in manufacture and possess lower blank levels. However, if commercial cartridges are
used, they shall be demonstrated to meet the performance criteria of this part of ISO 16000. Another
advantage of commercial cartridges is that they are available with larger particle size silica gel that results in a
lower pressure drop across the cartridge. These low pressure drop cartridges may be more suitable for
sampling air using battery-powered personal sampling pumps.
Carbonyl compound 2,4-Dinitrophenylhydrazine DNPH derivative
(aldehyde or ketone) (DNPH)
Key
R, R′ H, alkyl group, aromatic group
Figure 1 — Reaction of carbonyl compounds to form 2,4-dinitrophenylhydrazones
4 Limitations and interferences
4.1 General
The sampling flow rate specified in this part of ISO 16000 has been validated for sampling rates up to
1,5 l/min. This flow rate limitation is principally due to the high pressure drop (>8 kPa at 1,0 l/min) across the
user-prepared silica gel cartridges, which have particle sizes of 55 µm to 105 µm. These cartridges are not
generally compatible with battery-powered pumps used in personal sampling equipment (e.g. those used by
industrial hygienists).
The solid-sorbent sampling procedure is specific for sampling and analysis of formaldehyde. Interferences in
this method are caused by certain isomeric aldehydes or ketones that may be unresolved by the HPLC
system when analysing for other aldehydes and ketones. Any organic compounds that have the same
retention times and significant absorbance at 360 nm as the DNPH derivative of formaldehyde interfere. Such
interferences can often be overcome by altering the separation conditions (e.g. using alternative HPLC
columns or mobile phase compositions).
2 © ISO 2011 – All rights reserved
---------------------- Page: 8 ----------------------
ISO 16000-3:2011(E)
Formaldehyde contamination of the DNPH reagent is a frequently encountered problem. The DNPH shall be
purified by multiple recrystallizations in UV-grade acetonitrile (ACN). Recrystallization is accomplished, at
40 °C to 60 °C, by slow evaporation of the solvent to maximize crystal size. Impurity levels of carbonyl
compounds in the DNPH are determined prior to use by HPLC and should be less than 0,15 µg per cartridge.
Exposure of the DNPH-coated sampling cartridges to direct sunlight may produce artefacts and should be
[17]
avoided .
Acrolein and crotonaldehyde may not be accurately quantified by the method. Inaccurate results for these
[18]
compounds may result from the formation of multiple derivative peaks and the instability of the peak ratios .
Nitrogen dioxide reacts with DNPH. High concentrations of NO (e.g. for gas cooking stoves) may cause
2
problems as the retention time of the DNPH derivative may be similar to that of the DNPH formaldehyde
[13][14][19]
derivative, depending on the HPLC column and the parameters .
4.2 Ozone interference
If there is suspicion that abnormally high levels of ozone are present in the area being sampled (e.g. from
office copiers), special care should be exercised. Ozone has been shown to interfere negatively by reacting
[20]
with both DNPH and its derivatives (hydrazones) in the cartridge . The extent of interference depends on
the temporal variations of both the ozone and the carbonyl compounds and the duration of sampling.
Significant negative interference from ozone has been observed even at concentrations of formaldehyde and
[19]
3 3
ozone typical of clean ambient air (2 µg/m and 80 µg/m , respectively) . The presence of ozone in the
sample is readily inferred upon analysis by the appearance of new compounds with retention times shorter
than that of the hydrazone of formaldehyde. Figure 2 shows chromatograms of samples of a formaldehyde-
spiked air stream with and without ozone.
The most direct solution to ozone interference is to remove the ozone before the sampled air reaches the
cartridge. This can be accomplished by the use of an ozone denuder or scrubber placed in front of the
cartridge. Both ozone denuders and scrubber cartridges are commercially available. A denuder may be
constructed of 1 m of copper tubing of outside diameter 0,64 cm and of inside diameter 0,46 cm, that is filled
with a saturated solution of potassium iodide in water, allowed to stand for a few minutes (e.g. 5 min), drained
and dried with a stream of clean air or nitrogen for about 1 h. The capacity of the ozone denuder as specified
3
is about 200 µg/m h. Test aldehydes (formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde and
p-tolualdehyde) that were dynamically spiked into an ambient sample air stream passed through the ozone
[21]
denuder with practically no losses . Commercial ozone scrubbers made from a cartridge filled with 300 mg
[22]
to 500 mg of granular potassium iodide have also been found to be effective in removing ozone .
5 Safety measures
5.1 2,4-Dinitrophenylhydrazine is explosive in the dry state and shall be handled with extreme care. It is
also toxic (in the rat, LD = 654 mg/kg), has been shown to be mutagenic in some tests, and is irritating to the
50
eyes and skin.
5.2 Perchloric acid at concentrations less than 68 % mass fraction is stable and non-oxidizing at room
temperature. However, it is readily dehydrated at temperatures above 160 °C and can cause explosions on
contact with alcohols, wood, cellulose, and other oxidizable materials. It should be stored in a cool, dry place
and used only in a chemical fume hood with caution.
© ISO 2011 – All rights reserved 3
---------------------- Page: 9 ----------------------
ISO 16000-3:2011(E)
Key
A relative absorbance 1 unknown
t time 2 DNPH
A with ozone 3 formaldehyde
B without ozone 4 acetaldehyde
Figure 2 — Cartridge samples of formaldehyde in an air stream with and without ozone
6 Apparatus
Usual laboratory apparatus and in particular the following.
6.1 Sampling
6.1.1 Sampling cartridge, packed with silica gel and coated with DNPH in accordance with Clause 8, or as
available commercially.
The cartridge shall contain a minimum quantity of 350 mg of silica gel with a minimum DNPH loading of
0,29 % mass fraction. The ratio of the silica gel bed diameter to bed length shall not exceed 1:1. The capacity
of the cartridge for formaldehyde shall be at least 75 µg and the collection efficiency at least 95 % at a
sampling rate of 1,5 l/min. Sampling cartridges with very low blank levels and high performance are
commercially available.
NOTE A pressure drop through the user-prepared sample cartridge of about 19 kPa at a sampling rate of 1,5 l/min
has been observed. Some commercially available pre-coated cartridges exhibit lower pressure-drops, which permit the
use of battery-operated personal sampling pumps.
6.1.2 Air sampling pump, capable of accurately and precisely sampling at a flow rate of 0,1 l/min to
1,5 l/min.
6.1.3 Flow controller, mass flow meters and mass flow controllers, or other suitable device for metering
and setting air flow rates of 0,50 l/min to 1,20 l/min through the sample cartridge.
6.1.4 Flow calibrator, such as a rotameter, soap-bubble meter or wet test meter.
4 © ISO 2011 – All rights reserved
---------------------- Page: 10 ----------------------
ISO 16000-3:2011(E)
6.2 Sample preparation
6.2.1 Cartridge containers, e.g. borosilicate glass culture tubes (20 mm ¥ 125 mm) with polypropylene
screw caps, or other suitable containers, to transport coated cartridges.
6.2.2 Polyethylene gloves, to handle silica gel cartridges.
6.2.3 Transportation containers, friction-top metal cans (e.g. of volume 4 l) or other suitable containers,
with polyethylene air-bubble packing or other suitable padding, to hold and cushion the sealed cartridge
containers.
NOTE A heat-sealable foil-lined plastic pouch of the type included with some commercial pre-coated DNPH
cartridges can be used for storing a DNPH-coated cartridge after sampling, if appropriate.
6.2.4 Support for coating cartridges. A syringe rack, made from an aluminium plate
(0,16 cm ¥ 36 cm ¥ 53 cm) with adjustable legs on four corners. A matrix (5 ¥ 9) of circular holes of diameter
slightly larger than the diameter of the 10 ml syringes, symmetrically drilled from the centre of the plate, to
enable batch processing of 45 cartridges for cleaning, coating and/or sample elution (see Figure 3).
6.2.5 Cartridge-drying manifold, such as a support with gas connectors and with multiple standard male
syringe connectors (see Figure 3).
NOTE The apparatus specified in 6.2.4 and 6.2.5 is needed only if users choose to make their own DNPH-coated
cartridges.
6.3 Sample analysis
6.3.1 HPLC system, consisting of:
a) a mobile phase reservoir with an outgassing device (e.g. membrane under reduced pressure);
b) a high-pressure pump;
c) an injection valve (automatic sampler with a 25 µl or other convenient loop volume);
d) a C-18 reverse phase (RP) column (e.g. 25 cm ¥ 4,6 mm inside diameter, 5 µm particle size);
e) a UV detector or diode array detector operating at 360 nm;
f) a data system or strip chart recorder.
The DNPH-formaldehyde derivative is determined using isocratic reverse phase HPLC, equipped with an
ultraviolet (UV) absorption detector operated at 360 nm. A blank cartridge is likewise desorbed and analysed.
Formaldehyde and other carbonyl compounds in the sample are identified and quantified by comparison of
their retention times and peak heights or peak areas with those of standard solutions.
NOTE 1 Most commercial HPLC analytical systems are adequate for this application.
NOTE 2 A column oven can be used to assure constant column operating temperature and improve reproducibility.
6.3.2 Syringes and pipettes
6.3.2.1 HPLC injection syringes, with capacity at least four times the loop volume (see 6.3.1).
6.3.2.2 Syringes, volume 10 ml, used to prepare DNPH-coated cartridges (polypropylene syringes are
adequate).
6.3.2.3 Syringe fittings and plugs, to connect cartridges to the sampling system and to cap prepared
cartridges.
6.3.2.4 Pipettes, positive-displacement, repetitive-dispensing type, with capacities in the 0 ml to 10 ml
[1]
range, ISO 8655-2 .
© ISO 2011 – All rights reserved 5
---------------------- Page: 11 ----------------------
ISO 16000-3:2011(E)
a) Rack for coating cartridges
b) Rack for drying DNPH-coated cartridges
Key
1 10 ml glass syringes 5 N gas stream
2
2 test tube rack 6 syringe fitting
3 cartridges 7 waste vials
4 waste beakers
Figure 3 — Syringe rack for coating and drying sample cartridges
6 © ISO 2011 – All rights reserved
---------------------- Page: 12 ----------------------
ISO 16000-3:2011(E)
7 Reagents and materials
During the analysis, unless otherwise stated, use only reagents of recognized analytical grade, e.g. best
quality grade, grade for chemical analysis or grade for HPLC analysis, and distilled or demineralized water or
water of equivalent purity.
7.1 2,4-Dinitrophenylhydrazine, recrystallized at least twice with UV-grade acetonitrile before use.
7.2 Acetonitrile, UV grade (each batch of solvent should be tested before use).
7.3 Perchloric acid, 60 % mass fraction, r = 1,51 kg/l, reagent grade (best source).
7.4 Hydrochloric acid, 36,5 % to 38 % mass fraction, r = 1,19 kg/l, reagent grade (best source).
7.5 Hydrochloric acid, 2 mol/l, reagent grade (best source).
7.6 Formaldehyde, 37 % mass fraction solution, reagent grade (best source).
7.7 Aldehydes and ketones, high purity, used for preparation of DNPH derivative standards (optional).
7.8 Ethanol or methanol, HPLC grade.
7.9 Nitrogen, high purity grade (best source).
7.10 Charcoal, granular (best source).
7.11 Helium, high purity grade (best source).
8 Preparation of reagents and cartridges
8.1 Purification of 2,4-dinitrophenylhydrazine
Formaldehyde contamination of the DNPH reagent is a frequently encountered problem. The DNPH (7.1) shall
be purified by multiple recrystallizations in UV-grade acetonitrile (7.2). Recrystallization is accomplished, at
40 °C to 60 °C, by slow evaporation of the solvent to maximize crystal size. Impurity levels of carbonyl
compounds in the DNPH are determined prior to use by HPLC and should be less than 0,15 µg per cartridge
and per individual compound.
Prepare a supersaturated solution of DNPH by boiling excess DNPH in 200 ml of acetonitrile for
approximately 1 h. After 1 h, remove and transfer the supernatant to a covered beaker on a hot plate and
allow gradual cooling to 40 °C to 60 °C. Maintain the solution at this temperature (40 °C) until 95 % volume
fraction of solvent has evaporated. Decant the solution to waste, and rinse the remaining crystals twice with
three times their apparent volume of acetonitrile. Transfer the crystals to another clean beaker, add 200 ml of
acetonitrile, heat to boiling, and again let crystals grow slowly at 40 °C to 60 °C until 95 % volume fraction of
the solvent has evaporated. Repeat the rinsing process as specified above. Take an aliquot of the second
rinse, dilute 10 times with acetonitrile, acidify with 1 ml of 3,8 mol/l perchloric acid (7.3) per 100 ml of DNPH
solution, and analyse by HPLC, in accordance with 9.3.4.
WARNING — Carry out this procedure under a properly ventilated hood and behind an explosion
shield.
NOTE An acid is necessary to catalyse the reaction of carbonyl compounds with DNPH. Most strong inorganic acids
such as hydrochloric, sulfuric, phosphoric or perchloric acids perform satisfactorily. In rare cases, hydrochloric and sulfuric
acids cause problems.
An acceptable impurity level is <0,025 µg/ml of formaldehyde hydrazone in recrystallized DNPH reagent or
0,02 % mass fraction of the DNPH.
© ISO 2011 – All rights reserved 7
---------------------- Page: 13 ----------------------
ISO 16000-3:2011(E)
If the impurity level is not acceptable for the intended sampling application, repeat recrystallization. Transfer
the purified crystals to an all-glass reagent bottle, add 200 ml of acetonitrile, stopper, shake gently, and allow
to stand overnight. Analyse the supernatant by HPLC according to 9.3.4. If the impurity level is not satisfactory,
pipette off the solution to waste, then add 25 ml of acetonitrile to the purified crystals. Repeat rinsing with
20 ml portions of acetonitrile until a satisfactorily low impurity level in the supernatant is confirmed by HPLC
analysis.
If the impurity level is satisfactory, add another 25 ml of acetonitrile, stopper, shake the reagent bottle, then
set aside. The saturated solution above the purified crystals is the stock DNPH reagent. Maintain only a
minimum volume of saturated solution adequate for day-to-day operation. This minimizes waste of purified
reagent, should it be necessary to re-rinse the crystals to decrease the level of impurity for applications
requiring more stringent purity specifications. Use clean pipettes when removing saturated DNPH stock
solution for any analytical applications. Do not pour the stock solution from the reagent bottle.
8.2 Preparation of DNPH-formaldehyde derivative
To a portion of the recrystallized DNPH (8.1) add sufficient 2 mol/l HCl (7.5) to obtain an approximately
saturated
...
NORME ISO
INTERNATIONALE 16000-3
Deuxième édition
2011-10-15
Air intérieur —
Partie 3:
Dosage du formaldéhyde et d'autres
composés carbonylés dans l'air intérieur
et dans l'air des chambres d'essai —
Méthode par échantillonnage actif
Indoor air —
Part 3: Determination of formaldehyde and other carbonyl compounds
in indoor air and test chamber air — Active sampling method
Numéro de référence
ISO 16000-3:2011(F)
©
ISO 2011
---------------------- Page: 1 ----------------------
ISO 16000-3:2011(F)
DOCUMENT PROTÉGÉ PAR COPYRIGHT
© ISO 2011
Droits de reproduction réservés. Sauf prescription différente, aucune partie de cette publication ne peut être reproduite ni utilisée sous
quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie et les microfilms, sans l'accord écrit
de l'ISO à l'adresse ci-après ou du comité membre de l'ISO dans le pays du demandeur.
ISO copyright office
Case postale 56 CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Publié en Suisse
ii © ISO 2011 – Tous droits réservés
---------------------- Page: 2 ----------------------
ISO 16000-3:2011(F)
Sommaire Page
Avant-propos . iv
Introduction . vi
1 Domaine d'application . 1
2 Références normatives . 2
3 Principe . 2
4 Limites et interférences . 2
5 Mesures de sécurité . 3
6 Appareillage . 4
7 Réactifs et matériaux . 7
8 Préparation des réactifs et des cartouches . 7
9 Mode opératoire . 10
10 Calculs . 20
11 Critères de performance et assurance qualité . 21
12 Fidélité et incertitude . 23
13 Rapport d'essai . 23
Annexe A (informative) Fidélité et incertitude. 24
Annexe B (informative) Points de fusion des dérivés DNPH-carbonylés . 26
Bibliographie . 27
© ISO 2011 – Tous droits réservés iii
---------------------- Page: 3 ----------------------
ISO 16000-3:2011(F)
Avant-propos
L'ISO (Organisation internationale de normalisation) est une fédération mondiale d'organismes nationaux de
normalisation (comités membres de l'ISO). L'élaboration des Normes internationales est en général confiée
aux comités techniques de l'ISO. Chaque comité membre intéressé par une étude a le droit de faire partie du
comité technique créé à cet effet. Les organisations internationales, gouvernementales et non
gouvernementales, en liaison avec l'ISO participent également aux travaux. L'ISO collabore étroitement avec
la Commission électrotechnique internationale (CEI) en ce qui concerne la normalisation électrotechnique.
Les Normes internationales sont rédigées conformément aux règles données dans les Directives ISO/CEI,
Partie 2.
La tâche principale des comités techniques est d'élaborer les Normes internationales. Les projets de Normes
internationales adoptés par les comités techniques sont soumis aux comités membres pour vote. Leur
publication comme Normes internationales requiert l'approbation de 75 % au moins des comités membres
votants.
L'attention est appelée sur le fait que certains des éléments du présent document peuvent faire l'objet de
droits de propriété intellectuelle ou de droits analogues. L'ISO ne saurait être tenue pour responsable de ne
pas avoir identifié de tels droits de propriété et averti de leur existence.
L'ISO 16000-3 a été élaborée par le comité technique ISO/TC 146, Qualité de l'air, sous-comité SC 6, Air
intérieur.
Cette deuxième édition annule et remplace la première édition (ISO 16000-3:2001), qui a fait l'objet d'une
révision technique.
L'ISO 16000 comprend les parties suivantes, présentées sous le titre général Air intérieur:
Partie 1: Aspects généraux de la stratégie d'échantillonnage
Partie 2: Stratégie d'échantillonnage du formaldéhyde
Partie 3: Dosage du formaldéhyde et d'autres composés carbonylés dans l'air intérieur et dans l'air des
chambres d'essai — Méthode par échantillonnage actif
Partie 4: Dosage du formaldéhyde — Méthode par échantillonnage diffusif
Partie 5: Stratégie d'échantillonnage pour les composés organiques volatils (COV)
Partie 6: Dosage des composés organiques volatils dans l'air intérieur des locaux et chambres d'essai
®
par échantillonnage actif sur le sorbant Tenax TA , désorption thermique et chromatographie en phase
gazeuse utilisant MS ou MS-FID
Partie 7: Stratégie d'échantillonnage pour la détermination des concentrations en fibres d'amiante en
suspension dans l'air
Partie 8: Détermination des âges moyens locaux de l'air dans des bâtiments pour caractériser les
conditions de ventilation
Partie 9: Dosage de l'émission de composés organiques volatils de produits de construction et d'objets
d'équipement — Méthode de la chambre d'essai d'émission
Partie 10: Dosage de l'émission de composés organiques volatils de produits de construction et d'objets
d'équipement — Méthode de la cellule d'essai d'émission
iv © ISO 2011 – Tous droits réservés
---------------------- Page: 4 ----------------------
ISO 16000-3:2011(F)
Partie 11: Dosage de l'émission de composés organiques volatils de produits de construction et d'objets
d'équipement — Échantillonnage, conservation des échantillons et préparation d'échantillons pour essai
Partie 12: Stratégie d'échantillonnage des polychlorobiphényles (PCB), des polychlorodibenzo-p-dioxines
(PCDD), des polychlorodibenzofuranes (PCDF) et des hydrocarbures aromatiques polycycliques (HAP)
Partie 13: Dosage des polychlorobiphényles (PCB) de type dioxine et des polychlorodibenzo-p-dioxines
(PCDD)/polychlorodibenzofuranes (PCDF) totaux (en phase gazeuse et en phase particulaire) —
Collecte sur des filtres adsorbants
Partie 14: Dosage des polychlorobiphényles (PCB) de type dioxine et des polychlorodibenzo-p-dioxines
(PCDD)/polychlorodibenzofuranes (PCDF) totaux (en phase gazeuse et en phase particulaire) —
Extraction, purification et analyse par chromatographie en phase gazeuse haute résolution et
spectrométrie de masse
Partie 15: Stratégie d'échantillonnage du dioxyde d'azote (NO )
2
Partie 16: Détection et dénombrement des moisissures — Échantillonnage par filtration
Partie 17: Détection et dénombrement des moisissures — Méthode par culture
Partie 18: Détection et dénombrement des moisissures — Échantillonnage par impaction
Partie 19: Stratégie d'échantillonnage des moisissures
Partie 23: Essai de performance pour l'évaluation de la réduction des concentrations en formaldéhyde
par des matériaux de construction sorptifs
Partie 24: Essai de performance pour l'évaluation de la réduction des concentrations en composés
organiques volatils (sauf formaldéhyde) par des matériaux de construction sorptifs
Partie 25: Dosage de l'émission de composés organiques semi-volatils des produits de construction —
Méthode de la micro-chambre
Partie 26: Stratégie d'échantillonnage du dioxyde de carbone (CO )
2
Partie 28: Détermination des émissions d'odeurs des produits de construction au moyen de chambres
d'essai
Les parties suivantes sont en cours d'élaboration:
Partie 21: Détection et dénombrement des moisissures — Échantillonnage à partir de matériaux
Partie 27: Détermination de la poussière fibreuse déposée sur les surfaces par microscopie électronique
à balayage (MEB) (méthode directe)
Partie 29: Méthodes d'essai pour détecteurs de composés organiques volatils (COV)
Partie 30: Essai sensoriel de l'air intérieur
Partie 31: Mesurage des ignifugeants basés sur des composés organophosphorés — Ester d'acide
phosphorique
Partie 32: Investigation de polluants et autres facteurs nocifs dans les constructions — Inspections
© ISO 2011 – Tous droits réservés v
---------------------- Page: 5 ----------------------
ISO 16000-3:2011(F)
Introduction
La présente partie de l'ISO 16000 est destinée à être utilisée pour caractériser l'air intérieur selon la stratégie
d'échantillonnage spécifiée dans l'ISO 16000-2. Elle est applicable au formaldéhyde et à d'autres composés
carbonylés. Elle a été soumise à essai pour 14 aldéhydes et cétones. Le formaldéhyde est le composé
carbonylé le plus simple, avec un atome de carbone, un atome d'oxygène et deux atomes d'hydrogène. Sous
sa forme mono-moléculaire, c'est un gaz réactif incolore et âcre. Il a été utilisé dans la production de résines,
d'adhésifs et de mousses isolantes d'urée formaldéhyde. Les émissions des panneaux de particules
(copeaux) et des isolations murales sont les principales sources de formaldéhyde dans l'air intérieur.
Le formaldéhyde est collecté en faisant passer de l'air à travers un milieu réactif qui convertit le composé en
un dérivé de pression de vapeur inférieure qui est plus efficacement retenu par l'échantillonneur et peut être
aisément analysé. La présente partie de l'ISO 16000 permet de doser le formaldéhyde et d'autres composés
carbonylés par réaction avec de la 2,4-dinitrophénylhydrazine imprégnée sur un sorbant pour les convertir en
leurs hydrazones correspondantes, qui peuvent être récupérées et mesurées avec une haute sensibilité,
précision et justesse. Les autres composés carbonylés qui peuvent être émis dans l'air par les solvants, les
adhésifs, les produits cosmétiques et d'autres sources peuvent également être dosés en utilisant la présente
partie de l'ISO 16000.
[12]
Le mode opératoire d'échantillonnage repose sur la méthode TO-11A de l'Agence américaine de protection
de l'environnement (EPA).
[15]
Le formaldéhyde et certains autres composés carbonylés ont un fort potentiel toxique .
[7][8] [2]-[6]
L'ISO 16017 et l'ISO 12219 portent plus particulièrement sur les mesurages relatifs aux composés
organiques volatils (COV).
vi © ISO 2011 – Tous droits réservés
---------------------- Page: 6 ----------------------
NORME INTERNATIONALE ISO 16000-3:2011(F)
Air intérieur —
Partie 3:
Dosage du formaldéhyde et d'autres composés carbonylés
dans l'air intérieur et dans l'air des chambres d'essai —
Méthode par échantillonnage actif
AVERTISSEMENT — Il convient que l'utilisateur de la présente partie de l'ISO 16000 connaisse bien
les pratiques courantes de laboratoire. La présente partie de l'ISO 16000 n'a pas pour but de traiter
tous les problèmes de sécurité qui sont, le cas échéant, liés à son utilisation. Il incombe à l'utilisateur
d'établir des pratiques appropriées en matière d'hygiène et de sécurité, et de s'assurer de la
conformité à la réglementation nationale en vigueur.
1 Domaine d'application
La présente partie de l'ISO 16000 spécifie un dosage du formaldéhyde (HCHO) et d'autres composés
1)
carbonylés (aldéhydes et cétones) dans l'air. La méthode est spécifique au formaldéhyde. Toutefois, si elle
est modifiée, au moins 12 autres composés carbonylés peuvent être détectés et quantifiés. Elle convient au
dosage du formaldéhyde et d'autres composés carbonylés dans la plage de concentration comprise entre
3 3
environ 1 µg/m et 1 mg/m . La méthode d'échantillonnage fournit un résultat moyen pondéré dans le temps
(TWA). Elle peut être utilisée pour l'échantillonnage du formaldéhyde dans l'air à long terme (1 h à 24 h) ou à
court terme (5 min à 60 min).
La présente partie de l'ISO 16000 spécifie un mode opératoire d'échantillonnage et d'analyse pour le
formaldéhyde et d'autres composés carbonylés qui implique un prélèvement de l'air sur des cartouches
imprégnées de 2,4-dinitrophénylhydrazine (DNPH) et une analyse ultérieure par chromatographie en phase
[12][16]
liquide à haute performance (CLHP) avec détection par absorption ultraviolette . La méthode n'est pas
adaptée pour les composés carbonylés à plus longues chaînes ou insaturés.
La présente partie de l'ISO 16000 est applicable au dosage des composés suivants:
acétaldéhyde 2,5-diméthylbenzaldéhyde m -tolualdéhyde
acétone formaldéhyde o -tolualdéhyde
benzaldéhyde isovaléraldéhyde p -tolualdéhyde
butyraldéhyde propionaldéhyde valéraldéhyde
capronaldéhyde
1) Dans la présente partie de l'ISO 16000, les noms traditionnels sont utilisés à la place de la nomenclature
systématique de l'IUPAC. Quelques noms équivalents sont:
acétaldéhyde: éthanal formaldéhyde: méthanal o -tolualdéhyde: 2-méthylbenzaldéhyde
acétone: 2-propanone isovaléraldéhyde: 3-méthylbutanal p -tolualdéhyde: 4-méthylbenzaldéhyde
butyraldéhyde: butanal propionaldéhyde: propanal valéraldéhyde: pentanal
capronaldéhyde: hexanal m -tolualdéhyde: 3-méthylbenzaldéhyde
© ISO 2011 – Tous droits réservés 1
---------------------- Page: 7 ----------------------
ISO 16000-3:2011(F)
2 Références normatives
Les documents de référence suivants sont indispensables pour l'application du présent document. Pour les
références datées, seule l'édition citée s'applique. Pour les références non datées, la dernière édition du
document de référence s'applique (y compris les éventuels amendements).
ISO/CEI 17025, Exigences générales concernant la compétence des laboratoires d'étalonnages et d'essais
3 Principe
La méthode spécifiée dans la présente partie de l'ISO 16000 implique l'aspiration d'air dans une cartouche
contenant du gel de silice imprégnée de réactif 2,4-dinitrophénylhydrazine (DNPH). Le principe de la méthode
repose sur la réaction spécifique du groupe carbonyle avec la DNPH en présence d'un acide pour former des
dérivés stables selon la réaction indiquée à la Figure 1. Les dérivés de DNPH sont analysés en termes de
présence d'aldéhydes et de cétones apparentées en utilisant la chromatographie en phase liquide à haute
performance (CLHP) avec une détection UV ou une détection à barrette de diodes. La détection a été élargie
à d'autres composés carbonylés qui peuvent être dosés comme indiqué en 9.3.5.
La présente partie de l'ISO 16000 indique à l'utilisateur comment préparer des cartouches d'échantillonnage à
partir de cartouches de gel de silice de qualité chromatographique disponibles dans le commerce, par
application de DNPH acidifiée sur chaque cartouche. Des cartouches de gel de silice pré-imprégnées de
DNPH sont également disponibles et sont recommandées car elles présentent en général une fabrication plus
uniforme et possèdent des niveaux de blanc moindres. Cependant, si des cartouches commerciales sont
utilisées, elles doivent répondre aux critères de performance de la présente partie de l'ISO 16000. Un autre
avantage des cartouches commerciales est qu'elles sont disponibles avec un gel de silice dont la
granulométrie est plus élevée, ce qui entraîne une moindre chute de pression dans la cartouche. Ces
cartouches à faible chute de pression peuvent être plus appropriées à l'échantillonnage de l'air au moyen de
pompes de prélèvement individuelles alimentées par batterie.
Composé carbonylé 2,4-Dinitrophénylhydrazine Dérivé DNPH
(aldéhyde ou cétone) (DNPH)
Légende
R, R' H, groupe alkyle, groupe aromatique
Figure 1 — Réaction des composés carbonylés pour former des 2,4-dinitrophénylhydrazones
4 Limites et interférences
4.1 Généralités
Le débit d'échantillonnage spécifié dans la présente partie de l'ISO 16000 a été validé pour des vitesses
d'échantillonnage pouvant atteindre 1,5 l/min. Cette limite de débit est principalement liée à l'importante chute
de pression (8 kPa à 1,0 l/min) dans les cartouches de gel de silice préparées par l'utilisateur, qui possèdent
des tailles de particules de 55 µm à 105 µm. Généralement, ces cartouches ne sont pas compatibles avec les
pompes alimentées par batterie utilisées dans les équipements d'échantillonnage individuels (par exemple
ceux utilisés par les hygiénistes industriels).
Le mode opératoire d'échantillonnage sur sorbant solide est spécifique à l'échantillonnage et à l'analyse du
formaldéhyde. Dans la présente méthode, les interférences sont provoquées par certains aldéhydes ou
cétones isomères qui ne sont pas séparés par le système CLHP lors de l'analyse d'autres aldéhydes et
cétones. Les composés organiques qui ont un même temps de rétention et une même absorbance
significative à 360 nm que le dérivé DNPH du formaldéhyde interfèrent. Ces interférences peuvent souvent
2 © ISO 2011 – Tous droits réservés
---------------------- Page: 8 ----------------------
ISO 16000-3:2011(F)
être supprimées en modifiant les conditions de séparation (par exemple en utilisant d'autres colonnes CLHP
ou des compositions de phase mobile).
La contamination par le formaldéhyde du réactif DNPH est un problème fréquent. La DNPH doit être purifiée
par de multiples recristallisations dans de l'acétonitrile de qualité UV (ACN). La recristallisation est effectuée
entre 40 °C et 60 °C, par lente évaporation du solvant, de façon à maximiser la taille des cristaux. Les niveaux
d'impureté des composés carbonylés dans la DNPH sont déterminés avant utilisation, par CLHP, et il convient
qu'ils soient inférieurs à 0,15 µg par cartouche.
Il convient d'éviter toute exposition à la lumière directe du soleil des cartouches d'échantillonnage imprégnées
[17]
de DNPH qui peut produire des artéfacts .
La méthode ne permet pas de quantifier avec précision l'acroléine et le crotonaldéhyde. En raison de la
[18]
formation de multiples pics dérivés et de l'instabilité des rapports de pic , des résultats imprécis peuvent
être obtenus pour ces composés.
Le dioxyde d'azote réagit avec la DNPH. De fortes concentrations en NO (par exemple pour les gazinières)
2
peuvent engendrer des problèmes car le temps de rétention du dérivé DNPH peut être similaire à celui du
[13][14][19]
dérivé DNPH du formaldéhyde, en fonction de la colonne CLHP et des paramètres .
4.2 Interférence due à l'ozone
Il convient de prêter une attention particulière en cas de suspicion de niveaux d'ozone anormalement élevés
dans la zone d'échantillonnage (par exemple les photocopieurs de bureau). L'ozone s'est avérée interférer
[20]
négativement en réagissant avec la DNPH et ses dérivés (les hydrazones) dans la cartouche . Le degré
d'interférence dépend des variations temporelles de l'ozone et des composés carbonylés, ainsi que de la
durée d'échantillonnage. Une importante interférence négative de l'ozone a été observée, même à des
3 3
concentrations en formaldéhyde et en ozone typiques de l'air ambiant propre (2 µg/m et 80 µg/m ,
[19]
respectivement) . Lors de l'analyse, la présence d'ozone dans l'échantillon est facilement décelée par
l'apparition de nouveaux composés dont les temps de rétention sont plus courts que ceux de l'hydrazone de
formaldéhyde. La Figure 2 illustre des chromatogrammes d'échantillons d'un flux d'air supplémenté en
formaldéhyde avec et sans ozone.
La solution la plus directe pour résoudre le problème d'interférence de l'ozone consiste à éliminer l'ozone
avant que l'air échantillonné n'atteigne la cartouche. Pour cela, un décomposeur ou un épurateur d'ozone
placé en face de la cartouche peut être utilisé. Les décomposeurs et les cartouches épuratrices d'ozone sont
disponibles dans le commerce. Un décomposeur peut être équipé d'un tuyau en cuivre de 1 m de 0,64 cm de
diamètre extérieur et de 0,46 cm de diamètre intérieur, rempli d'une solution aqueuse saturée d'iodure de
potassium, laissé au repos pendant quelques minutes (par exemple 5 min), purgé et séché avec un flux d'air
ou d'azote propre pendant environ 1 h. La capacité du décomposeur d'ozone tel que spécifié est d'environ
3
200 µg/m h. Les aldéhydes d'essai (formaldéhyde, acétaldéhyde, propionaldéhyde, benzaldéhyde et
p-tolualdéhyde) de marquage dynamique dans un flux d'air d'échantillonnage ambiant ont traversé le
[21]
décomposeur d'ozone avec pratiquement aucune perte . Les épurateurs d'ozone commerciaux constitués
d'une cartouche remplie avec 300 mg à 500 mg d'iodure de potassium granulaire se sont également révélés
[22]
efficaces pour éliminer l'ozone .
5 Mesures de sécurité
5.1 La 2,4-dinitrophénylhydrazine est explosive à l'état sec et doit être manipulée avec un soin tout
particulier. Elle est également toxique (chez le rat, LD = 654 mg/kg). Certains essais ont démontré qu'elle
50
est mutagène et elle est irritante pour la peau et les yeux.
5.2 L'acide perchlorique est stable et non oxydant à température ambiante, à des concentrations inférieures
à 68 % en fraction massique. Cependant, il est facilement déshydraté à des températures supérieures à
160 °C et peut provoquer des explosions au contact des alcools, du bois, de la cellulose et d'autres matériaux
oxydables. Il convient de le stocker dans un endroit sec et frais et de l'utiliser avec précaution, sous une hotte
d'aspiration uniquement.
© ISO 2011 – Tous droits réservés 3
---------------------- Page: 9 ----------------------
ISO 16000-3:2011(F)
Légende
A absorbance relative 1 inconnu
t temps 2 DNPH
A avec ozone 3 formaldéhyde
B sans ozone 4 acétaldéhyde
Figure 2 — Échantillons de formaldéhyde de la cartouche dans un flux d'air avec et sans ozone
6 Appareillage
Appareillage de laboratoire habituel et en particulier ce qui suit.
6.1 Échantillonnage
6.1.1 Cartouche d'échantillonnage, garnie de gel de silice et imprégnée de DNPH conformément à
l'Article 8, ou cartouche disponible dans le commerce.
La cartouche doit contenir une quantité minimale de 350 mg de gel de silice avec une charge minimale de
DNPH de 0,29 % en fraction massique. Le rapport du diamètre du lit à la longueur du lit du gel de silice ne
doit pas dépasser 1:1. La capacité de la cartouche pour le formaldéhyde doit être d'au moins 75 µg et
l'efficacité de prélèvement d'au moins 95 % à un débit d'échantillonnage de 1,5 l/min. Des cartouches
d'échantillonnage à très faibles niveaux de blanc et à haute performance sont disponibles dans le commerce.
NOTE Une chute de pression d'environ 19 kPa a été observée dans la cartouche d'échantillonnage préparée par
l'utilisateur, à un débit d'échantillonnage de 1,5 l/min. Certaines cartouches pré-imprégnées disponibles dans le commerce
présentent des chutes de pression moindres, ce qui permet d'utiliser des pompes de prélèvement individuelles alimentées
par batterie.
6.1.2 Pompe de prélèvement d'air, capable d'échantillonner avec justesse et précision à un débit de
0,1 l/min à 1,5 l/min.
6.1.3 Régulateur de débit, débitmètres massiques et régulateurs de débit massiques, ou tout autre
dispositif approprié pour mesurer et régler le débit d'air entre 0,50 l/min et 1,20 l/min dans la cartouche
d'échantillonnage.
4 © ISO 2011 – Tous droits réservés
---------------------- Page: 10 ----------------------
ISO 16000-3:2011(F)
6.1.4 Appareil d'étalonnage de débit, tel qu'un rotamètre, un débitmètre à lame de savon ou un compteur
humide.
6.2 Préparation de l'échantillon
6.2.1 Récipients pour cartouches, par exemple tubes de culture en verre borosilicaté (20 mm 125 mm)
avec bouchons à vis en polypropylène, ou autres récipients appropriés, pour transporter les cartouches
imprégnées.
6.2.2 Gants en polyéthylène, pour manipuler les cartouches contenant du gel de silice.
6.2.3 Récipients de transport, boîtiers métalliques à couvercle hermétique (par exemple d'un volume de
4 l) ou autres récipients appropriés, avec emballage à bulles d'air en polyéthylène ou autre rembourrage
approprié, pour contenir et protéger les récipients pour cartouche fermés hermétiquement.
NOTE Un sachet en plastique thermosoudable du type inclus avec certaines cartouches commerciales pré-
imprégnées de DNPH peut être utilisé pour stocker une cartouche imprégnée de DNPH après l'échantillonnage, si
approprié.
6.2.4 Support pour l'imprégnation des cartouches. Un rack pour seringues, constitué d'une plaque en
aluminium (0,16 cm ¥ 36 cm ¥ 53 cm) avec des pieds réglables aux quatre coins. Une matrice (5 ¥ 9) de trous
circulaires de diamètre légèrement supérieur à celui des seringues de 10 ml, percés symétriquement depuis
le centre de la plaque, pour le traitement discontinu de 45 cartouches pour le nettoyage, l'imprégnation et/ou
l'élution de l'échantillon (voir Figure 3).
6.2.5 Rampe de séchage des cartouches, tel qu'un support avec des raccords à gaz et avec plusieurs
connecteurs mâles pour seringues normalisés (voir Figure 3).
NOTE L'appareillage spécifié en 6.2.4 et 6.2.5 n'est nécessaire que si l'utilisateur choisit de fabriquer ses propres
cartouches imprégnées de DNPH.
6.3 Analyse de l'échantillon
6.3.1 Système CLHP, constitué:
a) d'un réservoir de phase mobile équipé d'un dispositif de dégazage (par exemple membrane sous
pression réduite);
b) d'une pompe à haute pression;
c) d'une vanne d'injection (échantillonneur automatique d'un volume de 25 µl ou d'un autre volume de
boucle approprié);
d) d'une colonne C-18 à phase inversée (par exemple diamètre intérieur de 4,6 mm ¥ 25 cm, taille des
particules de 5 µm);
e) d'un détecteur UV ou d'un détecteur à barrette de diodes fonctionnant à 360 nm;
f) d'un système d'acquisition de données ou d'un enregistreur à papier déroulant.
Le dérivé DNPH-formaldéhyde est dosé par CLHP à phase inversée isocratique, équipée d'un détecteur par
absorption UV fonctionnant à 360 nm. Une cartouche à blanc est également désorbée et analysée. Le
formaldéhyde et les autres composés carbonylés présents dans l'échantillon sont identifiés et quantifiés en
comparant leurs temps de rétention et leurs hauteurs ou surfaces de pic avec ceux des solutions étalons.
NOTE 1 La plupart des systèmes d'analyse CLHP commerciaux conviennent à cette application.
NOTE 2 Un four peut être utilisé pour garantir une température de fonctionnement constante dans la colonne et pour
améliorer la reproductibilité.
© ISO 2011 – Tous droits réservés 5
---------------------- Page: 11 ----------------------
ISO 16000-3:2011(F)
a) Rack pour l'imprégnation des cartouches
b) Rack pour le séchage des cartouches imprégnées de DNPH
Légende
1 seringues en verre de 10 ml 5 flux de gaz N
2
2 rack de tubes à essai 6 raccord pour seringues
3 cartouches 7 flacons pour déchets
4 béchers pour déchets
Figure 3 — Rack de seringues pour l'imprégnation et le séchage des cartouches d'échantillonnage
6 © ISO 2011 – Tous droits réservés
---------------------- Page: 12 ----------------------
ISO 16000-3:2011(F)
6.3.2 Seringues et pipettes
6.3.2.1 Seringues d'injection CLHP, d'une capacité d'au moins quatre fois le volume de boucle
(voir 6.3.1).
6.3.2.2 Seringues, d'un volume de 10 ml, utilisées pour préparer les cartouches imprégnées de DNPH
(les seringues en polypropylène conviennent).
6.3.2.3 Raccords et bouchons pour seringues, pour raccorder les cartouches au système
d'échantillonnage et pour boucher les cartouches préparées.
[1]
6.3.2.4 Pipettes, volumétriques et à distribution répétitive, d'une capacité de 0 ml à 10 ml, ISO 8655-2 .
7 Réactifs et matériaux
Au cours de l'analyse, sauf indication contraire, utiliser uniquement des réactifs de qualité analytique
reconnue, par exemple de qualité optimale, de qualité appropriée pour l'analyse chimique ou de qualité
appropriée pour l'analyse CLHP et de l'eau distillée ou déminéralisée ou de l'eau de pureté équivalente.
7.1 2,4-Dinitrophénylhydrazine, recristallisée au moins deux fois à l'aide d'acétonitrile de qualité UV avant
utilisation.
7.2 Acétonitrile, de qualité UV (il convient de soumettre à essai chaque lot de solvant avant utilisation).
7.3 Acide perchlorique, 60 % en fraction massique, r = 1,51 kg/l, qualité réactif (meilleure origine).
7.4 Acide chlorhydrique, 36,5 % à 38 % en fraction massique, r = 1,19 kg/l, qualité réactif (meilleure
origine).
7.5 Acide chlorhydrique, 2 mol/l, de qualité réactif (meilleure origine).
7.6 Formaldéhyde, solution à 37 % (fraction massique), qualité réactif (meilleure origine).
7.7 Aldéhydes et cétones, pureté élevée, utilisés pour la prépa
...
SLOVENSKI STANDARD
oSIST ISO 16000-3:2011
01-december-2011
1RWUDQML]UDNGHO 'RORþHYDQMHIRUPDOGHKLGDLQGUXJLKNDUERQLOQLKVSRMLQY
QRWUDQMHP]UDNXLQ]UDNXYSUHVNXVQLKNRPRUDK0HWRGDDNWLYQHJDY]RUþHQMD
Indoor air - Part 3: Determination of formaldehyde and other carbonyl compounds in
indoor air and test chamber air - Active sampling method
Air intérieur - Partie 3: Dosage du formaldéhyde et d'autres composés carbonylés dans
l'air intérieur et dans l'air des chambres d'essai - Méthode par échantillonnage actif
Ta slovenski standard je istoveten z: ISO 16000-3:2011
ICS:
13.040.20 Kakovost okoljskega zraka Ambient atmospheres
oSIST ISO 16000-3:2011 en,fr
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
oSIST ISO 16000-3:2011
---------------------- Page: 2 ----------------------
oSIST ISO 16000-3:2011
INTERNATIONAL ISO
STANDARD 16000-3
Second edition
2011-10-15
Indoor air —
Part 3:
Determination of formaldehyde and other
carbonyl compounds in indoor air and
test chamber air — Active sampling
method
Air intérieur —
Partie 3: Dosage du formaldéhyde et d'autres composés carbonylés
dans l'air intérieur et dans l'air des chambres d'essai — Méthode par
échantillonnage actif
Reference number
ISO 16000-3:2011(E)
©
ISO 2011
---------------------- Page: 3 ----------------------
oSIST ISO 16000-3:2011
ISO 16000-3:2011(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2011
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2011 – All rights reserved
---------------------- Page: 4 ----------------------
oSIST ISO 16000-3:2011
ISO 16000-3:2011(E)
Contents Page
Foreword . iv
Introduction . vi
1 Scope . 1
2 Normative references . 2
3 Principle . 2
4 Limitations and interferences . 2
5 Safety measures . 3
6 Apparatus . 4
7 Reagents and materials . 7
8 Preparation of reagents and cartridges . 7
9 Procedure . 10
10 Calculations . 19
11 Performance criteria and quality assurance . 20
12 Precision and uncertainty . 22
13 Test report . 22
Annex A (informative) Precision and uncertainty . 23
Annex B (informative) Melting points of DNPH-carbonyl derivatives . 25
Bibliography . 26
© ISO 2011 – All rights reserved iii
---------------------- Page: 5 ----------------------
oSIST ISO 16000-3:2011
ISO 16000-3:2011(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 16000-3 was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 6, Indoor air.
This second edition cancels and replaces the first edition (ISO 16000-3:2001), which has been technically
revised.
ISO 16000 consists of the following parts, under the general title Indoor air:
Part 1: General aspects of sampling strategy
Part 2: Sampling strategy for formaldehyde
Part 3: Determination of formaldehyde and other carbonyl compounds in indoor air and test chamber
air — Active sampling method
Part 4: Determination of formaldehyde — Diffusive sampling method
Part 5: Sampling strategy for volatile organic compounds (VOCs)
Part 6: Determination of volatile organic compounds in indoor and test chamber air by active sampling on
®
Tenax TA sorbent, thermal desorption and gas chromatography using MS or MS-FID
Part 7: Sampling strategy for determination of airborne asbestos fibre concentrations
Part 8: Determination of local mean ages of air in buildings for characterizing ventilation conditions
Part 9: Determination of the emission of volatile organic compounds from building products and
furnishing — Emission test chamber method
Part 10: Determination of the emission of volatile organic compounds from building products and
furnishing — Emission test cell method
Part 11: Determination of the emission of volatile organic compounds from building products and
furnishing — Sampling, storage of samples and preparation of test specimens
Part 12: Sampling strategy for polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins
(PCDDs), polychlorinated dibenzofurans (PCDFs) and polycyclic aromatic hydrocarbons (PAHs)
iv © ISO 2011 – All rights reserved
---------------------- Page: 6 ----------------------
oSIST ISO 16000-3:2011
ISO 16000-3:2011(E)
Part 13: Determination of total (gas and particle-phase) polychlorinated dioxin-like biphenyls (PCBs) and
polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDDs/PCDFs) — Collection on sorbent-backed filters
Part 14: Determination of total (gas and particle-phase) polychlorinated dioxin-like biphenyls (PCBs) and
polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDDs/PCDFs) — Extraction, clean-up and analysis by
high-resolution gas chromatography and mass spectrometry
Part 15: Sampling strategy for nitrogen dioxide (NO )
2
Part 16: Detection and enumeration of moulds — Sampling by filtration
Part 17: Detection and enumeration of moulds — Culture-based method
Part 18: Detection and enumeration of moulds — Sampling by impaction
Part 19: Sampling strategy for moulds
Part 23: Performance test for evaluating the reduction of formaldehyde concentrations by sorptive
building materials
Part 24: Performance test for evaluating the reduction of volatile organic compound (except
formaldehyde) concentrations by sorptive building materials
Part 25: Determination of the emission of semi-volatile organic compounds by building products — Micro-
chamber method
Part 26: Sampling strategy for carbon dioxide (CO )
2
Part 28: Determination of odour emissions from building products using test chambers
The following parts are under preparation:
Part 21: Detection and enumeration of moulds — Sampling from materials
Part 27: Determination of settled fibrous dust on surfaces by SEM (scanning electron microscopy) (direct
method)
Part 29: Test methods for VOC detectors
Part 30: Sensory testing of indoor air
Part 31: Measurement of flame retardants and plasticizers based on organophosphorus compounds —
Phosphoric acid ester
Part 32: Investigation of constructions on pollutants and other injurious factors — Inspections
© ISO 2011 – All rights reserved v
---------------------- Page: 7 ----------------------
oSIST ISO 16000-3:2011
ISO 16000-3:2011(E)
Introduction
This part of ISO 16000 is intended to be used for characterizing indoor air following the sampling strategy
specified in ISO 16000-2. It is applicable to formaldehyde and other carbonyl compounds. It has been tested
for 14 aldehydes and ketones. Formaldehyde is the simplest carbonyl compound, with one carbon, one
oxygen and two hydrogen atoms. In its monomolecular state, it is a colourless, pungent, reactive gas. It has
been used in the production of urea-formaldehyde resins, adhesives, and insulating foams. Emissions from
particle (chip) board and wall insulation are the major sources of formaldehyde in indoor air.
Formaldehyde is collected by passing air through a reactive medium that converts the compound to a
derivative of lower vapour pressure that is more efficiently retained by the sampler and can be easily analysed.
This part of ISO 16000 determines formaldehyde and other carbonyl compounds by reaction with
2,4-dinitrophenylhydrazine coated on to a sorbent to convert them to their corresponding hydrazones, which
can be recovered and measured with high sensitivity, precision, and accuracy. Other carbonyl compounds
that may be emitted into air from solvents, adhesives, cosmetics, and other sources can also be determined
using this part of ISO 16000.
[12]
The sampling procedure is based on US EPA method TO-11A .
[15]
Formaldehyde and certain other carbonyl compounds have a high toxic potential .
[7][8] [2]–[6]
ISO 16017 and ISO 12219 also focus on volatile organic compound (VOC) measurements.
vi © ISO 2011 – All rights reserved
---------------------- Page: 8 ----------------------
oSIST ISO 16000-3:2011
INTERNATIONAL STANDARD ISO 16000-3:2011(E)
Indoor air —
Part 3:
Determination of formaldehyde and other carbonyl compounds
in indoor air and test chamber air — Active sampling method
WARNING — Persons using this part of ISO 16000 should be familiar with normal laboratory practice.
This part of ISO 16000 does not purport to address all of the safety problems, if any, associated with
its use. It is the responsibility of the user to establish appropriate safety and health practices and to
ensure compliance with any national regulatory conditions.
1 Scope
This part of ISO 16000 specifies a determination of formaldehyde (HCHO) and other carbonyl compounds
1
(aldehydes and ketones) in air. The method is specific to formaldehyde but, with modification, at least
12 other aromatic as well as saturated and unsaturated aliphatic carbonyl compounds can be detected and
quantified. It is suitable for determination of formaldehyde and other carbonyl compounds in the approximate
3 3
concentration range 1 µg/m to 1 mg/m . The sampling method gives a time-weighted average (TWA) sample.
It can be used for long-term (1 h to 24 h) or short-term (5 min to 60 min) sampling of air for formaldehyde.
This part of ISO 16000 specifies a sampling and analysis procedure for formaldehyde and other carbonyl
compounds that involves collection from air on to adsorbent cartridges coated with 2,4-dinitrophenylhydrazine
(DNPH) and subsequent analysis of the hydrazones formed by high performance liquid chromatography
[12],[16]
(HPLC) with detection by ultraviolet absorption . The method is not suitable for longer chained or
unsaturated carbonyl compounds.
This part of ISO 16000 applies to the determination of:
acetaldehyde 2,5-dimethylbenzaldehyde m -tolualdehyde
acetone formaldehyde o -tolualdehyde
benzaldehyde isovaleraldehyde p -tolualdehyde
butyraldehyde propionaldehyde valeraldehyde
capronaldehyde
1 Instead of systematic IUPAC nomenclature, traditional names are used in this part of ISO 16000. Some equivalent
names are:
acetaldehyde: ethanal formaldehyde: methanal o -tolualdehyde: 2-methylbenzaldehyde
acetone: 2-propanone isovaleraldehyde: 3-methylbutanal p -tolualdehyde: 4-methylbenzaldehyde
butyraldehyde: butanal propionaldehyde: propanal valeraldehyde: pentanal
capronaldehyde: hexanal m -tolualdehyde: 3-methylbenzaldehyde
© ISO 2011 – All rights reserved 1
---------------------- Page: 9 ----------------------
oSIST ISO 16000-3:2011
ISO 16000-3:2011(E)
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories
3 Principle
The method specified in this part of ISO 16000 involves drawing air through a cartridge containing silica gel
coated with 2,4-dinitrophenylhydrazine (DNPH) reagent. The principle of the method is based on the specific
reaction of a carbonyl group with DNPH in the presence of an acid to form stable derivatives according to the
reaction shown in Figure 1. The DNPH derivatives are analysed for the parent aldehydes and ketones utilizing
high performance liquid chromatography (HPLC) with UV detection or diode array detection. The detection
has been extended to other carbonyl compounds that can be determined as outlined in 9.3.5.
This part of ISO 16000 instructs the user on how to prepare sampling cartridges from commercially available
chromatographic grade silica gel cartridges by the application of acidified DNPH to each cartridge.
Alternatively, pre-coated DNPH silica gel cartridges are available and are recommended since they are
generally more uniform in manufacture and possess lower blank levels. However, if commercial cartridges are
used, they shall be demonstrated to meet the performance criteria of this part of ISO 16000. Another
advantage of commercial cartridges is that they are available with larger particle size silica gel that results in a
lower pressure drop across the cartridge. These low pressure drop cartridges may be more suitable for
sampling air using battery-powered personal sampling pumps.
Carbonyl compound 2,4-Dinitrophenylhydrazine DNPH derivative
(aldehyde or ketone) (DNPH)
Key
R, R′ H, alkyl group, aromatic group
Figure 1 — Reaction of carbonyl compounds to form 2,4-dinitrophenylhydrazones
4 Limitations and interferences
4.1 General
The sampling flow rate specified in this part of ISO 16000 has been validated for sampling rates up to
1,5 l/min. This flow rate limitation is principally due to the high pressure drop (>8 kPa at 1,0 l/min) across the
user-prepared silica gel cartridges, which have particle sizes of 55 µm to 105 µm. These cartridges are not
generally compatible with battery-powered pumps used in personal sampling equipment (e.g. those used by
industrial hygienists).
The solid-sorbent sampling procedure is specific for sampling and analysis of formaldehyde. Interferences in
this method are caused by certain isomeric aldehydes or ketones that may be unresolved by the HPLC
system when analysing for other aldehydes and ketones. Any organic compounds that have the same
retention times and significant absorbance at 360 nm as the DNPH derivative of formaldehyde interfere. Such
interferences can often be overcome by altering the separation conditions (e.g. using alternative HPLC
columns or mobile phase compositions).
2 © ISO 2011 – All rights reserved
---------------------- Page: 10 ----------------------
oSIST ISO 16000-3:2011
ISO 16000-3:2011(E)
Formaldehyde contamination of the DNPH reagent is a frequently encountered problem. The DNPH shall be
purified by multiple recrystallizations in UV-grade acetonitrile (ACN). Recrystallization is accomplished, at
40 °C to 60 °C, by slow evaporation of the solvent to maximize crystal size. Impurity levels of carbonyl
compounds in the DNPH are determined prior to use by HPLC and should be less than 0,15 µg per cartridge.
Exposure of the DNPH-coated sampling cartridges to direct sunlight may produce artefacts and should be
[17]
avoided .
Acrolein and crotonaldehyde may not be accurately quantified by the method. Inaccurate results for these
[18]
compounds may result from the formation of multiple derivative peaks and the instability of the peak ratios .
Nitrogen dioxide reacts with DNPH. High concentrations of NO (e.g. for gas cooking stoves) may cause
2
problems as the retention time of the DNPH derivative may be similar to that of the DNPH formaldehyde
[13][14][19]
derivative, depending on the HPLC column and the parameters .
4.2 Ozone interference
If there is suspicion that abnormally high levels of ozone are present in the area being sampled (e.g. from
office copiers), special care should be exercised. Ozone has been shown to interfere negatively by reacting
[20]
with both DNPH and its derivatives (hydrazones) in the cartridge . The extent of interference depends on
the temporal variations of both the ozone and the carbonyl compounds and the duration of sampling.
Significant negative interference from ozone has been observed even at concentrations of formaldehyde and
[19]
3 3
ozone typical of clean ambient air (2 µg/m and 80 µg/m , respectively) . The presence of ozone in the
sample is readily inferred upon analysis by the appearance of new compounds with retention times shorter
than that of the hydrazone of formaldehyde. Figure 2 shows chromatograms of samples of a formaldehyde-
spiked air stream with and without ozone.
The most direct solution to ozone interference is to remove the ozone before the sampled air reaches the
cartridge. This can be accomplished by the use of an ozone denuder or scrubber placed in front of the
cartridge. Both ozone denuders and scrubber cartridges are commercially available. A denuder may be
constructed of 1 m of copper tubing of outside diameter 0,64 cm and of inside diameter 0,46 cm, that is filled
with a saturated solution of potassium iodide in water, allowed to stand for a few minutes (e.g. 5 min), drained
and dried with a stream of clean air or nitrogen for about 1 h. The capacity of the ozone denuder as specified
3
is about 200 µg/m h. Test aldehydes (formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde and
p-tolualdehyde) that were dynamically spiked into an ambient sample air stream passed through the ozone
[21]
denuder with practically no losses . Commercial ozone scrubbers made from a cartridge filled with 300 mg
[22]
to 500 mg of granular potassium iodide have also been found to be effective in removing ozone .
5 Safety measures
5.1 2,4-Dinitrophenylhydrazine is explosive in the dry state and shall be handled with extreme care. It is
also toxic (in the rat, LD = 654 mg/kg), has been shown to be mutagenic in some tests, and is irritating to the
50
eyes and skin.
5.2 Perchloric acid at concentrations less than 68 % mass fraction is stable and non-oxidizing at room
temperature. However, it is readily dehydrated at temperatures above 160 °C and can cause explosions on
contact with alcohols, wood, cellulose, and other oxidizable materials. It should be stored in a cool, dry place
and used only in a chemical fume hood with caution.
© ISO 2011 – All rights reserved 3
---------------------- Page: 11 ----------------------
oSIST ISO 16000-3:2011
ISO 16000-3:2011(E)
Key
A relative absorbance 1 unknown
t time 2 DNPH
A with ozone 3 formaldehyde
B without ozone 4 acetaldehyde
Figure 2 — Cartridge samples of formaldehyde in an air stream with and without ozone
6 Apparatus
Usual laboratory apparatus and in particular the following.
6.1 Sampling
6.1.1 Sampling cartridge, packed with silica gel and coated with DNPH in accordance with Clause 8, or as
available commercially.
The cartridge shall contain a minimum quantity of 350 mg of silica gel with a minimum DNPH loading of
0,29 % mass fraction. The ratio of the silica gel bed diameter to bed length shall not exceed 1:1. The capacity
of the cartridge for formaldehyde shall be at least 75 µg and the collection efficiency at least 95 % at a
sampling rate of 1,5 l/min. Sampling cartridges with very low blank levels and high performance are
commercially available.
NOTE A pressure drop through the user-prepared sample cartridge of about 19 kPa at a sampling rate of 1,5 l/min
has been observed. Some commercially available pre-coated cartridges exhibit lower pressure-drops, which permit the
use of battery-operated personal sampling pumps.
6.1.2 Air sampling pump, capable of accurately and precisely sampling at a flow rate of 0,1 l/min to
1,5 l/min.
6.1.3 Flow controller, mass flow meters and mass flow controllers, or other suitable device for metering
and setting air flow rates of 0,50 l/min to 1,20 l/min through the sample cartridge.
6.1.4 Flow calibrator, such as a rotameter, soap-bubble meter or wet test meter.
4 © ISO 2011 – All rights reserved
---------------------- Page: 12 ----------------------
oSIST ISO 16000-3:2011
ISO 16000-3:2011(E)
6.2 Sample preparation
6.2.1 Cartridge containers, e.g. borosilicate glass culture tubes (20 mm ¥ 125 mm) with polypropylene
screw caps, or other suitable containers, to transport coated cartridges.
6.2.2 Polyethylene gloves, to handle silica gel cartridges.
6.2.3 Transportation containers, friction-top metal cans (e.g. of volume 4 l) or other suitable containers,
with polyethylene air-bubble packing or other suitable padding, to hold and cushion the sealed cartridge
containers.
NOTE A heat-sealable foil-lined plastic pouch of the type included with some commercial pre-coated DNPH
cartridges can be used for storing a DNPH-coated cartridge after sampling, if appropriate.
6.2.4 Support for coating cartridges. A syringe rack, made from an aluminium plate
(0,16 cm ¥ 36 cm ¥ 53 cm) with adjustable legs on four corners. A matrix (5 ¥ 9) of circular holes of diameter
slightly larger than the diameter of the 10 ml syringes, symmetrically drilled from the centre of the plate, to
enable batch processing of 45 cartridges for cleaning, coating and/or sample elution (see Figure 3).
6.2.5 Cartridge-drying manifold, such as a support with gas connectors and with multiple standard male
syringe connectors (see Figure 3).
NOTE The apparatus specified in 6.2.4 and 6.2.5 is needed only if users choose to make their own DNPH-coated
cartridges.
6.3 Sample analysis
6.3.1 HPLC system, consisting of:
a) a mobile phase reservoir with an outgassing device (e.g. membrane under reduced pressure);
b) a high-pressure pump;
c) an injection valve (automatic sampler with a 25 µl or other convenient loop volume);
d) a C-18 reverse phase (RP) column (e.g. 25 cm ¥ 4,6 mm inside diameter, 5 µm particle size);
e) a UV detector or diode array detector operating at 360 nm;
f) a data system or strip chart recorder.
The DNPH-formaldehyde derivative is determined using isocratic reverse phase HPLC, equipped with an
ultraviolet (UV) absorption detector operated at 360 nm. A blank cartridge is likewise desorbed and analysed.
Formaldehyde and other carbonyl compounds in the sample are identified and quantified by comparison of
their retention times and peak heights or peak areas with those of standard solutions.
NOTE 1 Most commercial HPLC analytical systems are adequate for this application.
NOTE 2 A column oven can be used to assure constant column operating temperature and improve reproducibility.
6.3.2 Syringes and pipettes
6.3.2.1 HPLC injection syringes, with capacity at least four times the loop volume (see 6.3.1).
6.3.2.2 Syringes, volume 10 ml, used to prepare DNPH-coated cartridges (polypropylene syringes are
adequate).
6.3.2.3 Syringe fittings and plugs, to connect cartridges to the sampling system and to cap prepared
cartridges.
6.3.2.4 Pipettes, positive-displacement, repetitive-dispensing type, with capacities in the 0 ml to 10 ml
[1]
range, ISO 8655-2 .
© ISO 2011 – All rights reserved 5
---------------------- Page: 13 ----------------------
oSIST ISO 16000-3:2011
ISO 16000-3:2011(E)
a) Rack for coating cartridges
b) Rack for drying DNPH-coated cartridges
Key
1 10 ml glass syringes 5 N gas stream
2
2 test tube rack 6 syringe fitting
3 cartridges 7 waste vials
4 waste beakers
Figure 3 — Syringe rack for coating and drying sample cartridges
6 © ISO 2011 – All rights reserved
---------------------- Page: 14 ----------------------
oSIST ISO 16000-3:2011
ISO 16000-3:2011(E)
7 Reagents and materials
During the analysis, unless otherwise stated, use only reagents of recognized analytical grade, e.g. best
quality grade, grade for chemical analysis or grade for HPLC analysis, and distilled or demineralized water or
water of equivalent purity.
7.1 2,4-Dinitrophenylhydrazine, recrystallized at least twice with UV-grade acetonitrile before use.
7.2 Acetonitrile, UV grade (each batch of solvent should be tested before use).
7.3 Perchloric acid, 60 % mass fraction, r = 1,51 kg/l, reagent grade (best source).
7.4 Hydrochloric acid, 36,5 % to 38 % mass fraction, r = 1,19 kg/l, reagent grade (best source).
7.5 Hydrochloric acid, 2 mol/l, reagent grade (best source).
7.6 Formaldehyde, 37 % mass fraction solution, reagent grade (best source).
7.7 Aldehydes and ketones, high purity, used for preparation of DNPH derivative standards (optional).
7.8 Ethanol or methanol, HPLC grade.
7.9 Nitrogen, high purity grade (best source).
7.10 Charcoal, granular (best source).
7.11 Helium, high purity grade (best source).
8 Preparation of reagents and cartridges
8.1 Purification of 2,4-dinitrophenylhydrazine
Formaldehyde contamination of the DNPH reagent is a frequently encountered problem. The DNPH (7.1) shall
be purified by multiple recrystallizations in UV-grade acetonitrile (7.2). Recrystallization is accomplished, at
40 °C to 60 °C, by slow evaporation of the solvent to maximize crystal size. Impurity levels of carbonyl
compounds in the DNPH are determined prior to use by HPLC and should be less than 0,15 µg per cartridge
and per individual compound.
Prepare a supersaturated solution of DNPH by boiling excess DNPH in 200 ml of acetonitrile for
approximately 1 h. After 1 h, remove and transfer the supernatant to a covered beaker on a hot plate and
allow gradual cooling to 40 °C to 60 °C. Maintain the solution at this temperature (40 °C) until 95 % volume
fraction of solvent has evaporated. Decant the solution to waste, and rinse the remaining crystals twice with
three times their apparent volume of acetonitrile. Transfer the crystals to another clean beaker, add 200 ml of
acetonitrile, heat to boiling, and again let crystals grow slowly at 40 °C to 60 °C until 95 % volume fraction of
the solvent has evaporated. Repeat the rinsing process as specified above. Take an aliquot of the second
rinse, dilute 10 times with acetonitrile, acidify with 1 ml of 3,8 mol/l perchloric acid (7.3) per 100 ml of DNPH
solution, and analyse by HPLC, in accordance with 9.3.4.
WARNING — Carry out this procedure under a properly ventilated hood and behind an explosion
shield.
NOTE An acid is necessary to catalyse the reaction of carbonyl compounds with DNPH. Most strong inorganic acids
such as hydrochloric, sulfuric, phosphoric or perchloric acids perform satisfactorily. In rare cases, hydrochloric and sulfuric
acids cause problems.
An acceptable impurity level is <0,025 µg/ml of formaldehyde hydrazone in recrystallized DNPH reagent or
0,02 % mass fraction of the DNPH.
© ISO 2011 – All rights reserved 7
---------------------- Page: 15 ----------------------
oSIST ISO 16000-3:2011
ISO 16000-3:2011(E)
If the impurity level is not acceptable for the intended sampling application, repeat recrystallization. Transfer
the purified crystals to an
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.