SIST EN ISO 16017-2:2003

Indoor, ambient and workplace air - Sampling and analysis of volatile organic compounds by sorbent tube/thermal desorption/capillary gas chromatography - Part 2: Diffusive sampling (ISO 16017-2:2003)

ISO 16017-2:2003 gives general guidance for the sampling and analysis of volatile organic compounds (VOCs) in air. It is applicable to indoor, ambient and workplace air.
ISO 16017-2:2003 is applicable to a wide range of VOCs, including hydrocarbons, halogenated hydrocarbons, ester, glycol ethers, ketones and alcohols. A number of sorbents are recommended for the sampling of these VOCs, each sorbent having a different range of applicability. Very polar compounds generally require derivatisation; very low boiling compounds are only partially retained by the sorbents and can only be estimated qualitatively. Semi-volatile compounds are fully retained by the sorbents, but may only be partially recovered.
ISO 16017-2:2003 is applicable to the measurement of airborne vapours of VOCs in a concentration range of approximately 0,002 mg/m3 to 100 mg/m3 individual organic for an exposure time of 8 h, or 0,3 g/m3 to 300 g/m3 individual organic for an exposure time of four weeks.
The upper limit of the useful range is set by the sorptive capacity of the sorbent used and by the linear dynamic range of the gas chromatograph column and detector or by the sample splitting capability of the analytical instrumentation used. The lower limit of the useful range depends on the noise level of the detector and on blank levels of analyte and/or interfering artefacts on the sorbent tubes. Artefacts are typically sub-nanogram for well-conditioned Tenax GR and carbonaceous sorbents, carbonized molecular sieves and pure charcoals; at low nanogram levels for Tenax TA and at 5 ng to 50 ng levels for other porous polymers.

Innenraumluft, Außenluft und Luft am Arbeitsplatz - Probenahme und Analyse flüchtiger organischer Verbindungen durch Sorptionsröhrchen/thermische Desorption/Kapillar-Gaschromatographie - Teil 2: Probenahme mit Passivsammlern (ISO 16017-2:2003)

Dieser Teil der ISO 16017 gibt allgemeine Hinweise für die Probenahme und Analyse flüchtiger organischer Verbindungen (VOC) in der Luft. Er ist anwendbar für die Bereiche Innenraumluft, Außenluft und Luft am Arbeitsplatz.
Dieser Teil der ISO 16017 ist für eine große Bandbreite von VOC, einschließlich Kohlenwasserstoffen, halogenierten Kohlenwasserstoffen, Estern, Glykolethern, Ketonen und Alkoholen, anwendbar. Eine Vielzahl an Sorbenzien ) wird für die Probenahme dieser VOC empfohlen; jedes Sorbens hat einen unterschiedlichen Anwendungsbereich. Sehr polare Verbindungen erfordern im Allgemeinen eine Derivatisierung. Verbindungen mit sehr niedrigem Siedepunkt werden nur partiell von den Sorbenzien zurückgehalten und können nur qualitativ abgeschätzt werden. Semi-flüchtige Verbindungen werden vollständig durch die Sorbenzien zurückgehalten, können aber nur zum Teil wiedergefunden werden.
Dieser Teil der ISO 16017 ist anwendbar für die Messung von VOC-haltigen Dämpfen in der Luft im Konzentrationsbereich von ungefähr 0,002 mg/m3 bis 100 mg/m3 für jede einzelne Verbindung bei einer Expositionszeit von 8 h oder 0,3 µg/m3 bis 300 µg/m3 für jede einzelne Verbindung bei einer Expositionszeit von 4 Wochen.
Die obere Nachweisgrenze eines sinnvollen Anwendungsbereiches wird durch die Sorptionskapazität des verwendeten Sorbens und durch den linearen dynamischen Bereich der Gaschromatographiesäule und des Detektors oder durch die Beschaffenheit des Probensplits in dem verwendeten analytischen Gerät festgelegt. Die untere Nachweisgrenze eines sinnvollen Anwendungsbereiches hängt von dem Rauschverhalten des Detektors und von den Blindwerten der zu bestimmenden Verbindungen und/oder den störenden Artefakten auf den Sorptionsröhrchen ab. Artefakte liegen typischerweise unterhalb des Nanogrammbereiches für gut gereinigtes Tenax

Air intérieur, air ambiant et air des lieux de travail - Echantillonnage et analyse des composés organiques volatils par tube a adsorption/désorption thermique/chromatographie en phase gazeuse sur capillaire - Partie 2: Echantillonnage par diffusion (ISO 16017-2:2003)

L'ISO 16017-2:2003 donne des lignes directrices générales portant sur l'échantillonnage et l'analyse des composés organiques volatils (COV) dans l'air. Elle est applicable à l'air intérieur, à l'air ambiant et à l'air des lieux de travail.
L'ISO 16017-2:2003 est applicable à un grand nombre de COV, y compris les hydrocarbures, les hydrocarbures halogénés, les esters, les éthers de glycol, les cétones et les alcools. Certains adsorbants sont recommandés pour l'échantillonnage de ces COV, chaque adsorbant ayant des applications particulières. Les composés fortement polaires doivent généralement être dérivés; les composés à point d'ébullition très bas sont seulement partiellement retenus par les adsorbants et leur évaluation ne peut être que qualitative. En revanche, les composés semi-volatils sont totalement retenus par les adsorbants mais ne peuvent être que partiellement récupérés.
L'ISO 16017-2:2003 est applicable au mesurage des vapeurs de COV en suspension dans l'air sur une étendue de concentration en masse des composés organiques individuels comprise entre 0,002 milligrammes par mètre cube et 100 milligrammes par mètre cube environ pour une durée d'exposition de 8 h, ou une étendue de concentration en masse des composés organiques individuels comprise entre 0,3 microgrammes par mètre cube et 300 microgrammes par mètre cube pour une durée d'exposition de quatre semaines.
La limite supérieure de l'étendue utile est déterminée par la capacité d'adsorption de l'adsorbant utilisé et par l'étendue dynamique linéaire de la colonne et du détecteur du chromatographe en phase gazeuse ou par la capacité de séparation des échantillons des instruments d'analyse utilisés. La limite inférieure de l'étendue utile dépend du niveau de bruit du détecteur et des niveaux à blanc de l'analyte et/ou des artefacts d'interférences sur les tubes à adsorption. Ces artefacts sont généralement d'un ordre inférieur au nanogramme pour les Tenax GR correctement étalonnés et pour les adsorbants carbonés tels que les matériaux de type Carbopack/Carbotrap, pour les tamis moléculaires carbonés tels que le Spherocarb et pour les charbons purs; ils sont de l'ordre du nanogramme pour le Tenax TA et de 5 nanogrammes à 50 nanogrammes pour les autres polymères poreux tels que les Chromosorbs et les Porapaks.

Notranji in zunanji zrak ter zrak na delovnem mestu – Vzorčenje in analiza hlapnih organskih spojin z absorpcijskimi cevkami in kapilarno plinsko kromatografijo s toplotno desorpcijo – 2. del: Difuzijsko vzorčenje (ISO 16017-2:2003)

General Information

• Status: Published
• Publication Date: 31-Oct-2003
• ICS: 13.040.01 - Air quality in general
• Technical Committee: KAZ - Air quality
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Nov-2003
• Due Date: 01-Nov-2003
• Completion Date: 01-Nov-2003
• Ref Project: EN ISO 16017-2:2003 - Indoor, ambient and workplace air - Sampling and analysis of volatile organic compounds by sorbent tube/thermal desorption/capillary gas chromatography - Part 2: Diffusive sampling (ISO 16017-2:2003)

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN ISO 16017-2:2003
01-november-2003
1RWUDQMLLQ]XQDQML]UDNWHU]UDNQDGHORYQHPPHVWX±9]RUþHQMHLQDQDOL]DKODSQLK
RUJDQVNLKVSRMLQ]DEVRUSFLMVNLPLFHYNDPLLQNDSLODUQRSOLQVNRNURPDWRJUDILMRV
WRSORWQRGHVRUSFLMR±GHO'LIX]LMVNRY]RUþHQMH,62
Indoor, ambient and workplace air - Sampling and analysis of volatile organic
compounds by sorbent tube/thermal desorption/capillary gas chromatography - Part 2:
Diffusive sampling (ISO 16017-2:2003)
Innenraumluft, Außenluft und Luft am Arbeitsplatz - Probenahme und Analyse flüchtiger
organischer Verbindungen durch Sorptionsröhrchen/thermische Desorption/Kapillar-
Gaschromatographie - Teil 2: Probenahme mit Passivsammlern (ISO 16017-2:2003)
Air intérieur, air ambiant et air des lieux de travail - Echantillonnage et analyse des
composés organiques volatils par tube a adsorption/désorption
thermique/chromatographie en phase gazeuse sur capillaire - Partie 2: Echantillonnage
par diffusion (ISO 16017-2:2003)
Ta slovenski standard je istoveten z: EN ISO 16017-2:2003
ICS:
13.040.01 Kakovost zraka na splošno Air quality in general
SIST EN ISO 16017-2:2003 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 16017-2:2003

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SIST EN ISO 16017-2:2003
EUROPEAN STANDARD
EN ISO 16017-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2003
ICS 13.040.01
English version
Indoor, ambient and workplace air - Sampling and analysis of
volatile organic compounds by sorbent tube/thermal
desorption/capillary gas chromatography - Part 2: Diffusive
sampling (ISO 16017-2:2003)
Air intérieur, air ambiant et air des lieux de travail - Innenraumluft, Außenluft und Luft am Arbeitsplatz -
Echantillonnage et analyse des composés organiques Probenahme und Analyse flüchtiger organischer
volatils par tube à adsorption/désorption Verbindungen durch Sorptionsröhrchen/thermische
thermique/chromatographie en phase gazeuse sur Desorption/Kapillar- Gaschromatographie - Teil 2:
capillaire - Partie 2: Echantillonnage par diffusion (ISO Probenahme mit Passivsammlern (ISO 16017-2:2003)
16017-2:2003)
This European Standard was approved by CEN on 21 March 2003.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United
Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2003 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 16017-2:2003 E
worldwide for CEN national Members.

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SIST EN ISO 16017-2:2003
EN ISO 16017-2:2003 (E)
CORRECTED  2003-07-16
Foreword
This document (EN ISO 16017-2:2003) has been prepared by Technical Committee ISO/TC 146
"Air quality" in collaboration with Technical Committee CEN/TC 264 "Air quality", the secretariat
of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of
an identical text or by endorsement, at the latest by November 2003, and conflicting national
standards shall be withdrawn at the latest by November 2003.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of
the following countries are bound to implement this European Standard: Austria, Belgium, Czech
Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and
the United Kingdom.
Endorsement notice
The text of ISO 16017-2:2003 has been approved by CEN as EN ISO 16017-2:2003 without any
modifications.
2

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SIST EN ISO 16017-2:2003


INTERNATIONAL ISO
STANDARD 16017-2
First edition
2003-05-15


Indoor, ambient and workplace air —
Sampling and analysis of volatile organic
compounds by sorbent tube/thermal
desorption/capillary gas
chromatography —
Part 2:
Diffusive sampling
Air intérieur, air ambiant et air des lieux de travail — Échantillonnage et
analyse des composés organiques volatils par tube à
adsorption/désorption thermique/chromatographie en phase gazeuse
sur capillaire —
Partie 2: Échantillonnage par diffusion




Reference number
ISO 16017-2:2003(E)
©
ISO 2003

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SIST EN ISO 16017-2:2003
ISO 16017-2:2003(E)
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©  ISO 2003
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ii © ISO 2003 — All rights reserved

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SIST EN ISO 16017-2:2003
ISO 16017-2:2003(E)
Contents Page
Foreword. iv
1 Scope. 1
2 Normative references . 1
3 Principle . 2
4 Reagents and materials. 2
5 Apparatus. 4
6 Sample tube conditioning . 5
7 Sampling . 5
8 Procedure. 6
8.1 Safety precautions . 6
8.2 Desorption and analysis. 6
8.3 Calibration. 8
8.4 Determination of sample concentration . 8
8.5 Determination of desorption efficiency . 8
8.6 Calibration of uptake rate. 8
9 Calculations. 9
9.1 Mass concentration of analyte . 9
9.2 Volume concentration of analyte . 9
9.3 Uptake rates. 10
10 Interferences. 10
11 Performance characteristics. 11
12 Test report. 11
13 Quality control. 11
Annex A (informative) Operating principles of diffusive sampling . 22
Annex B (informative) Description of sorbent types. 28
Annex C (informative) Guidance on sorbent selection. 29
Annex D (informative) Guidance on sorbent use . 30
Annex E (informative) Summary of data on overall uncertainty, precision, bias and storage. 31
Bibliography . 33

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SIST EN ISO 16017-2:2003
ISO 16017-2:2003(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 16017-2 was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 6, Indoor air.
ISO 16017 consists of the following parts, under the general title Indoor, ambient and workplace air —
Sampling and analysis of volatile organic compounds by sorbent tube/thermal desorption/capillary gas
chromatography:
 Part 1: Pumped sampling
 Part 2: Diffusive sampling

iv © ISO 2003 — All rights reserved

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SIST EN ISO 16017-2:2003
INTERNATIONAL STANDARD ISO 16017-2:2003(E)

Indoor, ambient and workplace air — Sampling and analysis of
volatile organic compounds by sorbent tube/thermal
desorption/capillary gas chromatography —
Part 2:
Diffusive sampling
1 Scope
This part of ISO 16017 gives general guidance for the sampling and analysis of volatile organic compounds
(VOCs) in air. It is applicable to indoor, ambient and workplace air.
This part of ISO 16017 is applicable to a wide range of VOCs, including hydrocarbons, halogenated
1)
hydrocarbons, esters, glycol ethers, ketones and alcohols. A number of sorbents are recommended for the
sampling of these VOCs, each sorbent having a different range of applicability. Very polar compounds
generally require derivatisation; very low boiling compounds are only partially retained by the sorbents and
can only be estimated qualitatively. Semi-volatile compounds are fully retained by the sorbents, but may only
be partially recovered.
This part of ISO 16017 is applicable to the measurement of airborne vapours of VOCs in a mass
3 3
concentration range of approximately 0,002 mg/m to 100 mg/m individual organic for an exposure time of
3 3
8 h, or 0,3 µg/m to 300 µg/m individual organic for an exposure time of four weeks.
The upper limit of the useful range is set by the sorptive capacity of the sorbent used and by the linear
dynamic range of the gas chromatograph column and detector or by the sample splitting capability of the
analytical instrumentation used. The lower limit of the useful range depends on the noise level of the detector
and on blank levels of analyte and/or interfering artefacts on the sorbent tubes. Artefacts are typically sub-
nanogram for well-conditioned Tenax GR and carbonaceous sorbents such as Carbopack/Carbotrap type
materials, carbonized molecular sieves such as Spherocarb and pure charcoals. Artefacts are typically at low
nanogram levels for Tenax TA and at 5 ng to 50 ng levels for other porous polymers such as Chromosorbs
and Porapaks.
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 16000-1, Indoor air — Part 1: General aspects of sampling strategy

1) The sorbents listed in Annex B and elsewhere in this part of ISO 16017 are those known to perform as specified under
this part of ISO 16017. Each sorbent or product that is identified by a trademarked name is unique and has a sole
manufacturer; however, they are widely available from many different suppliers. This information is given for the
convenience of users of this part of ISO 16017 and does not constitute an endorsement by ISO of the product named.
Equivalent products may be used if they can be shown to lead to the same results.
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SIST EN ISO 16017-2:2003
ISO 16017-2:2003(E)
3 Principle
The diffusive sampler (or samplers) is exposed to air for a measured time period. The rate of sampling is
determined by prior calibration in a standard atmosphere (see 8.6). The organic vapour migrates down the
tube by diffusion and is collected on the sorbent (see Annex A). The collected vapour (on each tube) is
desorbed by heat and is transferred under inert carrier gas into a gas chromatograph equipped with a capillary
column and a flame ionization detector or other suitable detector, where it is analysed. The analysis is
calibrated by means of liquid or vapour spiking onto a sorbent tube.
Information on possible saturation of the sorbent bed, the effect of transients and the effect of face velocity is
given in Annex A. Annex A also explains the dependence of effective uptake rates on the concentration level
of pollutants and the time of diffusive sampling, for non-ideal sorbents, which results in different values being
given in Tables 1 and 2. Further detailed information on the theory of performance of diffusive samplers is
[1]
given in prEN 13528-3 .
4 Reagents and materials
During the analysis, use only reagents of recognized analytical reagent grade.
Fresh standard solutions should be prepared weekly, or more frequently if evidence is noted of deterioration,
e.g. condensation reactions between alcohols and ketones.
4.1 Volatile organic compounds.
A wide range of VOCs are required as reagents for calibration purposes, using either liquid spiking (4.7 and
4.8) or vapour spiking (4.4 to 4.6) onto sorbent tubes.
4.2 Dilution solvent, for preparing calibration blend solutions for liquid spiking (4.7).
The solvent should be of chromatographic quality. It shall be free from compounds co-eluting with the
compound(s) of interest (4.1).
NOTE Methanol is frequently used. Alternative dilution solvents, e.g. ethyl acetate or cyclohexane, can be used,
particularly if there is no possibility of reaction or chromatographic co-elution.
4.3 Sorbents, preferably of particle size 0,18 mm to 0,25 mm (60 mesh to 80 mesh).
Each sorbent should be preconditioned under a flow of inert gas by heating it overnight at a temperature at
least 25 °C below the published maximum for that sorbent before packing the tubes. They shall be kept in a
clean atmosphere during cooling to room temperature, storage, and loading into the tubes. Wherever possible,
analytical desorption temperatures should be kept below those used for conditioning. Tubes prepacked by the
manufacturer are also available for most sorbents and as such only require conditioning. Care should be
taken with the disposal of the sorbents, using normal laboratory practice.
NOTE A guide for sorbent selection is given in Annex C. Equivalent sorbents may be used. A guide to sorbent
conditioning and analytical desorption parameters is given in Annex D. In most cases the sorbents can be used for indoor
air measurements as well as for ambient air and workplace atmosphere measurements.
4.4 Calibration standards.
Calibration standards are preferably prepared by loading required amounts of the compounds of interest on
sorbent tubes from standard atmospheres (see 4.5 and 4.6), as this procedure most closely resembles the
practical sampling situation.
If this way of preparation is not practicable, standards may be prepared by a liquid spiking procedure (see 4.7
and 4.8) provided that the accuracy of the spiking technique is established by one of the following methods:
a) by using procedures giving spiking levels fully traceable to primary standards of mass and/or volume;
2 © ISO 2003 — All rights reserved

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SIST EN ISO 16017-2:2003
ISO 16017-2:2003(E)
b) confirmed by comparison with reference materials, if available;
c) confirmed by comparison with standards produced using standard atmospheres;
d) confirmed by comparison with results of reference measurement procedures.
4.5 Standard atmospheres, of known concentrations of the compound(s) of interest.
Prepare standard atmospheres by an independent method. Methods described in ISO 6141 and several parts
of ISO 6145 are suitable (see Bibliography). If the procedure is not applied under conditions that allow the
establishment of full traceability of the generated concentrations to primary standards of mass and/or volume,
or if the chemical inertness of the generation system cannot be guaranteed, the concentrations shall be
confirmed using an independent procedure.
4.6 Standard sorbent tubes, loaded by spiking from standard atmospheres.
Prepare loaded sorbent tubes by passing an accurately known volume of the calibration atmosphere through
the sorbent tube, e.g. by means of a pump. The volume of atmosphere sampled shall not exceed the
breakthrough volume of the analyte-sorbent combination. After loading, disconnect and seal the tube. Prepare
fresh standards with each batch of samples. Prepare standard atmospheres of mass concentrations
3 3
equivalent to 10 mg/m and 100 µg/m . For workplace air, load sorbent tubes with 100 ml, 200 ml, 400 ml, 1 l,
3
2 l, or 4 l of the 10 mg/m atmosphere. For ambient or indoor air load sorbent tubes with 100 ml, 200 ml,
3
400 ml, 1 l, 2 l, 4 l or 10 l of the 100 µg/m atmosphere.
4.7 Solutions for liquid spiking.
4.7.1 Solution containing approximately 10 mg/ml of each liquid component.
Accurately weigh approximately 1 g of substance or substances of interest into a 100 ml volumetric flask,
starting with the least volatile substance. Make up to 100 ml with dilution solvent (4.2), stopper and shake to
mix.
4.7.2 Solutions containing approximately 1 mg/ml of liquid components.
Introduce 50 ml of dilution solvent into a 100 ml volumetric flask. Add 10 ml of solution 4.7.1 Make up to
100 ml with dilution solvent, stopper and shake to mix.
4.7.3 Solution containing approximately 100 µg/ml of each liquid component.
Accurately weigh approximately 10 mg of substance or substances of interest into a 100 ml volumetric flask,
starting with the least volatile substance. Make up to 100 ml with dilution solvent (4.2), stopper and shake to
mix.
4.7.4 Solution containing approximately 10 µg/ml of liquid components.
Introduce 50 ml of dilution solvent into a 100 ml volumetric flask. Add 10 ml of solution 4.7.3. Make up to
100 ml with dilution solvent, stopper and shake to mix.
4.7.5 Solution containing approximately 1 mg/ml of gas components.
For gases, e.g. ethylene oxide, a high-level calibration solution can be prepared as follows. Obtain gas at
atmospheric pressure by filling a small plastic gas bag from a gas cylinder containing pure gas. Fill a 1 ml gas-
tight syringe with 1 ml of the pure gas and close the valve of the syringe. Using a 2 ml septum vial, add 2 ml
dilution solvent and close with the septum cap. Insert the tip of the syringe needle through the septum cap into
the dilution solvent. Open the valve and withdraw the plunger slightly to allow the dilution solvent to enter the
syringe. The action of the gas dissolving in the dilution solvent creates a vacuum, and the syringe fills with
solvent. Return the solution to the flask. Flush the syringe twice with the solution and return the washings to
the flask. Calculate the mass of gas added using the gas laws, i.e. 1 mole of gas at STP (standard
temperature and pressure: 273,15 K and 1 013,25 hPa) occupies 22,4 litres.
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SIST EN ISO 16017-2:2003
ISO 16017-2:2003(E)
4.7.6 Solution containing approximately 10 µg/ml of gas components
For gases, e.g. ethylene oxide, a low level calibration solution may be prepared as follows. Obtain pure gas at
atmospheric pressure by filling a small plastic gas bag from a gas cylinder. Fill a 10 µl gas-tight syringe with
10 µl of the pure gas and close the valve of the syringe. Using a 2 ml septum vial, add 2 ml dilution solvent
and close with the septum cap. Insert the tip of the syringe needle through the septum cap into the dilution
solvent. Open the valve and withdraw the plunger slightly to allow the dilution solvent to enter the syringe. The
action of the gas dissolving in the dilution solvent creates a vacuum, and the syringe fills with solvent. Return
the solution to the flask. Flush the syringe twice with the solution and return the washings to the flask.
Calculate the mass of gas added using the gas laws, i.e. 1 mole of gas at STP occupies 22,4 litres.
4.8 Standard sorbent tubes loaded by liquid spiking
Loaded sorbent tubes are prepared by injecting aliquots of standard solutions onto clean sorbent tubes as
follows. A sorbent tube is fitted into the injection unit (5.7) through which inert purge gas is passed at
100 ml/min and a 1 µl to 4 µl aliquot of an appropriate standard solution injected through the septum. After
5 min, the tube is then disconnected and sealed. Prepare fresh standards with each batch of samples. For
workplace air, load sorbent tubes with 1 µl to 5 µl of solution 4.7.1, 4.7.2 or 4.7.5. For ambient and indoor air,
load sorbent tubes with 1 µl to 5 µl of solution 4.7.3, 4.7.4 or 4.7.6.
5 Apparatus
Use ordinary laboratory apparatus and the following devices.
5.1 Sorbent tubes.
These tubes shall be compatible with the thermal desorption apparatus to be used (5.6). Typically, but not
exclusively, they are constructed of stainless steel tubing of dimensions 6,3 mm (1/4 in) OD, 5 mm ID and
90 mm long. Tubes of other dimensions may be used, but the uptake rates given in Table 1 are based on
these tube dimensions. For labile analytes, such as sulfur-containing compounds, glass-lined or glass tubes
(typically 4 mm ID) should be used. Mark one end of the tube, for example by a scored ring, about 10 mm
from the (diffusive) sampling end. Pack the tubes with preconditioned sorbents so that the sorbent bed will be
within the desorber heated zone and a consistent gap of about 14 mm is retained at the marked (diffusive)
end of the tube.
Uptake rates in Table 1 are given for tubes with a nominal air gap (between sorbent bed and diffusive end
[2]
cap) of at least 14 mm. In practice, packed tube dimensions vary , and tubes should be rejected where the
air gap (between stainless steel screen retaining the sorbent bed and the end of the tube) is outside the range
14,0 mm to 14,6 mm.
Tubes contain between 200 mg and 1 000 mg sorbent, depending on sorbent density, which is typically about
250 mg porous polymer, or 500 mg carbon molecular sieve or graphitized carbon. The sorbents are retained
by a stainless steel gauze at the diffusion end and an unsilanized glass wool plug and/or a second stainless
gauze at the other end.
5.2 Sorbent tube end caps.
The tubes shall be sealed, e.g. with metal screw cap fittings with PTFE seals.
5.3 Sorbent tube end caps for sampling.
The diffusive end cap is similar to 5.2, but allows the ingress of vapour through a metal gauze, the size of the
opening being the same as the cross-section of the tube.
Some versions of the end cap incorporate a silicone membrane next to the gauze.
4 © ISO 2003 — All rights reserved

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SIST EN ISO 16017-2:2003
ISO 16017-2:2003(E)
5.4 Syringes.
A precision 10 µl liquid syringe readable to 0,1 µl, a precision 10 µl gas-tight syringe readable to 0,1 µl and a
precision 1 ml gas-tight syringe readable to 0,01 ml.
5.5 Gas chromatograph, fitted with a flame ionization detector, photoionization detector, mass
spectrometric or other suitable detector capable of detecting an injection of 0,5 ng toluene with a signal-to-
noise ratio of at least 5 to 1, and including a gas chromatograph capillary column capable of separating the
analytes of interest from other components.
5.6 Thermal desorption apparatus, for the two-stage thermal desorption of the sorbent tubes and transfer
of the desorbed vapours via an inert gas flow into a gas chromatograph.
A typical apparatus contains a mechanism for holding the tubes to be desorbed whilst they are heated and
purged simultaneously with inert carrier gas. The desorption temperature and time is adjustable, as is the
carrier gas flow rate. The apparatus should also incorporate additional features, such as automatic sample
tube loading, leak-testing, and a cold trap in the transfer line to concentrate the desorbed sample (8.2). The
desorbed sample, contained in the purge gas, is routed to the gas chromatograph and capillary column via a
heated transfer line.
5.7 Injection facility for preparing standards by liquid spiking.
A conventional gas chromatographic injection port may be used for preparing sample tube standards. This
can be used in situ, or it can be mounted separately. The carrier gas line to the injector should be retained.
The back of the injection port should be adapted if necessary to fit the sample tube. This can be done
conveniently by means of a compression coupling with an O-ring seal.
6 Sample tube conditioning
Prior to use, tubes should be reconditioned by desorbing them at a temperature at or just above the analytical
desorption temperature (see Annex D) for 10 min with a carrier gas flow of at least 100 ml/min. The carrier gas
flow should be towards the diffusive sampling end to prevent recontamination of the sorbents. Tubes should
then be analysed, using routine analytical parameters, to ensure that the thermal desorption blank is
sufficiently small. If the blank is unaccepta
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