ISO 11338-1:2003
(Main)Stationary source emissions — Determination of gas and particle-phase polycyclic aromatic hydrocarbons — Part 1: Sampling
Stationary source emissions — Determination of gas and particle-phase polycyclic aromatic hydrocarbons — Part 1: Sampling
ISO 11338-1:2003 describes methods for the determination of the mass concentration of polycyclic aromatic hydrocarbons (PAHs) in flue gas emissions from stationary sources such as aluminium smelters, coke works, waste incinerators, power stations, and industrial and domestic combustion appliances. ISO 11338-1:2003 describes three sampling methods, which are here regarded as of equivalent value, and specifies the minimum requirements for effective PAH sampling. The three sampling methods are the dilution method (A), the heated filter/condenser/adsorber method (B) and the cooled probe/adsorber method (C). All three methods are based on representative isokinetic sampling, as the PAHs are commonly associated with particles in flue gas. Information is provided to assist in the choice of the appropriate sampling method for the measurement application under consideration. ISO 11338-1:2003 is not applicable to the sampling of fugitive releases of PAHs. NOTE Methods for sample preparation, clean-up and analysis are described in ISO 11338-2 and are intended to be combined with one of the sampling methods described in ISO 11338-1 to complete the whole measurement procedure.
Émissions de sources fixes — Détermination des hydrocarbures aromatiques polycycliques sous forme gazeuse et particulaire — Partie 1: Échantillonnage
L'ISO 11338-1:2003 décrit des méthodes de détermination de la concentration massique des hydrocarbures aromatiques polycycliques (HAP) dans les émissions d'effluents gazeux provenant de sources fixes telles que les creusets d'aluminium, les cokeries, les incinérateurs de déchets, les centrales électriques et les installations industrielles et domestiques. L'ISO 11338-1:2003 décrit trois méthodes d'échantillonnage, considérées ici comme équivalentes, et spécifie les exigences minimales qui s'appliquent à l'échantillonnage effectif des HAP. Les trois méthodes d'échantillonnage sont la méthode de dilution (A), la méthode de filtration/condensation/adsorption avec chauffage (B) et la méthode de sondage/adsorption avec refroidissement (C). Les trois méthodes sont basées sur un échantillonnage isocinétique représentatif car les HAP sont en général associés à des particules dans des effluents gazeux. Des informations sont fournies pour aider au choix de la méthode d'échantillonnage appropriée pour l'application considérée. L'ISO 11338-1:2003 n'est pas applicable à l'échantillonnage des émissions fugitives de HAP. NOTE Les méthodes de préparation des échantillons, de purification et d'analyse sont décrites dans l'ISO 11338-2 et sont à combiner avec l'une des méthodes d'échantillonnage décrites dans l'ISO 11338-1 pour mener à bien l'ensemble du mode opératoire de mesurage.
Emisije nepremičnih virov – Določanje plinske in trdne faze policikličnih aromatskih ogljikovodikov - 1. del: Vzorčenje
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INTERNATIONAL ISO
STANDARD 11338-1
First edition
2003-06-01
Stationary source emissions —
Determination of gas and particle-phase
polycyclic aromatic hydrocarbons —
Part 1:
Sampling
Émissions de sources fixes — Détermination sous forme gazeuse et
particulaire des hydrocarbures aromatiques polycycliques —
Partie 1: Échantillonnage
Reference number
ISO 11338-1:2003(E)
©
ISO 2003
---------------------- Page: 1 ----------------------
ISO 11338-1:2003(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.
© ISO 2003
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 2003 — All rights reserved
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ISO 11338-1:2003(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope. 1
2 Normative references. 1
3 Terms and definitions. 2
4 Principles and minimum requirements for the three sampling methods . 2
4.1 Principles. 2
4.2 General minimum requirements for all sampling methods. 2
4.3 General preparation and sampling. 3
5 Method A — Dilution method. 4
5.1 Principle. 4
5.2 Minimum requirements. 4
5.3 Preparation and sampling. 5
6 Method B — (Heated) filter/condenser/adsorber method. 7
6.1 Principle. 7
6.2 Minimum requirements. 7
6.3 Preparation and sampling. 7
7 Method C — Cooled probed/adsorber method . 9
7.1 Principle. 9
7.2 Minimum requirements. 9
7.3 Preparation and sampling. 10
Annex A (informative) Applicability of the sampling methods . 12
Annex B (informative) Schematic presentations, dimensions and materials of some tested
sampling devices . 14
Bibliography . 25
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ISO 11338-1:2003(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 11338-1 was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 1, Stationary
source emissions.
ISO 11338 consists of the following parts, under the general title Stationary source emissions —
Determination of gas and particle-phase polycyclic aromatic hydrocarbons:
Part 1: Sampling
Part 2: Sample preparation, clean-up and determination
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ISO 11338-1:2003(E)
Introduction
Polycyclic aromatic hydrocarbons (PAHs) are a group of aromatic hydrocarbons, some members of which are
probable and others possible human carcinogens. Human exposure to PAHs can occur via food, soil, water,
air and skin contact with materials containing PAHs. While PAH are formed in natural processes (e.g. forest
fires), man-made atmospheric emissions of these compounds originate from the combustion of coal, gas,
wood and oil, from a range of industrial processes such as coke production, aluminium smelting and from
vehicles.
The quantification of atmospheric releases of PAH from stationary sources is an important part of the
environmental impact assessment of certain industrial processes.
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INTERNATIONAL STANDARD ISO 11338-1:2003(E)
Stationary source emissions — Determination of gas
and particle-phase polycyclic aromatic hydrocarbons —
Part 1:
Sampling
1 Scope
This part of ISO 11338 describes methods for the determination of the mass concentration of polycyclic
aromatic hydrocarbons (PAHs) in flue gas emissions from stationary sources such as aluminium smelters,
coke works, waste incinerators, power stations, and industrial and domestic combustion appliances.
This part of ISO 11338 describes three sampling methods, which are here regarded as of equivalent value,
and specifies the minimum requirements for effective PAH sampling. The three sampling methods are the
dilution method (A), the heated filter/condenser/adsorber method (B) and the cooled probe/adsorber
method (C). All three methods are based on representative isokinetic sampling, as the PAHs are commonly
associated with particles in flue gas.
Information is provided to assist in the choice of the appropriate sampling method for the measurement
application under consideration.
This part of ISO 11338 is not applicable to the sampling of fugitive releases of PAHs.
NOTE Methods for sample preparation, clean-up and analysis are described in ISO 11338-2 and are intended to be
combined with one of the sampling methods described in this part of ISO 11338 to complete the whole measurement
procedure.
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 4225:1994, Air quality — General aspects — Vocabulary
ISO 9096:1992, Stationary source emissions — Determination of concentration and mass flow rate of
particulate material in gas-carrying ducts — Manual gravimetric method
ISO 12141, Stationary source emissions — Determination of mass concentration of particulate matter (dust) at
low concentrations — Manual gravimetric method
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ISO 11338-1:2003(E)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 4225 and the following apply.
3.1
chimney
stack or final exit duct on a stationary process used for the dispersion of residual process gases
3.2
mass concentration
concentration of a substance in an emitted flue gas, expressed in units of mass per cubic metre
3.3
polycyclic aromatic hydrocarbon
PAH
compound that contains two or more fused aromatic rings made up only of carbon and hydrogen atoms
3.4
stationary source emissions
gases emitted by a stationary plant or process and transported to a chimney for dispersion into the
atmosphere
4 Principles and minimum requirements for the three sampling methods
4.1 Principles
Devices for the three sampling methods, illustrated in Figure B.1 (Method A), Figures B.2 and B.3 (Method B)
and Figure B.7 (Method C), can be applied for the sampling of PAH from stationary sources. They are
regarded as likely to produce equivalent results, however no comparative trials have been published to
establish this.
In general, as PAHs are present in both the vapour phase and on particles, the PAHs are collected in several
parts of the sampling train: the particle filter, condensate flask and solid or liquid adsorber. The choice of the
sampling method depends on the measurement application (see Table A.1 and Table A.2).
The three sampling methods A, B and C are discussed in detail in Clauses 5, 6 and 7, respectively.
Annex A provides further information on the applicability of the sampling methods.
After extraction and clean-up, the PAH are quantified either by High Performance Liquid Chromatography
(HPLC) using a fluorescence detector, diode array or UV detector, or by GC-FID/MS (low or high resolution
MS). Applicable methods for preparation, clean-up and determination are described in ISO 11338-2.
4.2 General minimum requirements for all sampling methods
The following steps shall be carried out irrespective of the sampling method chosen.
a) Carry out isokinetic sampling at representative points in the duct cross-section, in accordance with
ISO 9096.
b) Before sampling, rinse the inside of the sampling device with acetone, dichloromethane or methanol and
then with toluene. Alternatively, immerse the parts in methanol and subject them to ultrasonic vibration for
2 h, and subsequently dry at 150 °C. Store these washings and analyse only if the results indicate that
the sampler could have been contaminated before sampling, for example if the results unexpectedly
exceed the relevant emission limit.
c) Carry out a leak check before every sampling procedure.
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ISO 11338-1:2003(E)
If the joints in the equipment are of ground glass, any slight leak can be dealt with by wetting the joints
with a small amount of clean water. Greases should never be used for this purpose.
d) The minimum velocity in the sorbent bed shall be:
3
for XAD-2 (thickness 50 mm, volume 35 cm ): less than 34 cm/s;
3
for PU foam (thickness 50 mm, volume 98 cm ): less than 30 cm/s.
e) Check each batch of filters, solvents and reagents for preparation for background PAH levels.
f) The glass parts of the sampling devices shall be protected from light during and after sampling, cooled
after sampling and cleaned after the extraction procedure.
g) Clean the probe thoroughly after each sample is taken. Add the probe rinse to the rinse from the rest of
the sample.
h) If the probe is contaminated with particles which cannot be easily removed, wipe away the particles with a
quartz wool swab steeped in acetone. Extract this quartz wool swab together with the filter.
i) If the sampling device is cleaned at the measurement site for reuse there, the probe, the nozzle, the filter
casings and all other parts of the sampling apparatus which have been in contact with the sample gas
and so could still be contaminated shall, after cleaning to remove the sample, be rinsed with acetone,
dichloromethane or methanol and followed by a toluene rinse. As before, this sample shall be preserved
in case of concern about cross-contamination between samples.
j) Extract samples within 1 week and preferably within 24 h. Store the samples in the dark at – 7 °C.
4.3 General preparation and sampling
The following steps shall be carried out irrespective of the sampling method chosen.
a) Choose the sampling location with regard to the safety of the personnel, the suitability of the
measurement cross-section (in accordance with ISO 9096), accessibility and availability of electrical
power.
b) Before the sampling starts, determine the flue gas density, pressure, temperature and if possible the gas
composition. In addition, to ensure isokinetic conditions, determine the velocity and temperature profile
across the cross-section of the flue gas channel. Choose the correct size of the sampling probe nozzle
calculated from the flue gas velocity and the approximate maximum flowrate achievable through the
sampler to ensure that the sampler will be capable of isokinetic sampling at all the measurement points in
the duct cross-section.
c) The parts of the sampler which come into contact with the sample and which have been carefully cleaned
in the laboratory shall be
transported in clean boxes, all the components having been sealed carefully;
assembled in situ, carefully avoiding contact with the operator's fingers on the parts of the sampling
equipment which will later be in contact with the sample.
d) After sampling, store all materials containing sampled PAH under cooled conditions and protected from
light.
The following data shall be recorded during sampling:
sample volume (standard conditions);
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ISO 11338-1:2003(E)
sample temperature (in the gas meter);
mean flue gas velocity;
diameter of the stack;
moisture content of the flue gas;
mean oxygen content of the flue gas during the sampling period;
static pressure and temperature in the stack;
sampling flowrate.
To provide an estimate of the contamination present in the sampler and sampling matrices before sampling
and as a result of sampler assembly and transport, an additional sampling unit may be taken to the sampling
location, rinsed and analysed. Unfortunately contamination incidents are random in their occurrence, and so
this will only provide an estimate of the blank values. As a result, subtraction should not take place. However,
results in which the contribution of this blank is substantial should be treated with caution.
NOTE In order to obtain information on the performance of the sampler, internal standards can be added to the
sampling equipment (e.g. on the filters or the adsorbent) and their recovery measured. However, the internal standards
are bound to the filter in a manner different to that by which the native PAHs are bound to the fly ash, so there may be
differences in behaviour during sampling and extraction.
5 Method A — Dilution method
5.1 Principle
A proportion of the flue gas is collected isokinetically via a sampling probe heated to the temperature of the
flue gas. The flue gas is cooled very rapidly to temperatures below 40 °C in a mixing chamber using dried,
filtered and, if appropriate, cooled air. This dilution prevents condensation of water present in the gas sample.
In addition, dilution seeks to minimize the reactions of the separated PAH with other flue gas components, e.g.
NO, NO , SO , SO and HCl. The sampling conditions are similar to the natural dilution and cooling
2 2 3
processes of flue gases emitted into the atmosphere.
The diluted flue gas is then passed through a silicone-bonded glass fibre filter impregnated with paraffin oil.
This retains PAH components with 4 to 7 rings. If sampling for more volatile PAHs (2- or 3-ring compounds) is
1)
required, a solid adsorbent can be incorporated downstream of the filter in the sampling train.
3 3
The sample gas flowrate through the sampling probe should be in the range of 2 m /h to 8 m /h. Normally
3 3
within 1,5 h of sampling, sufficient PAH for analysis has been collected, usually in about 8 m to 10 m . After
sampling, the filter and, if used, the solid adsorbent are extracted and analysed.
A schematic representation of a tested sampling device is given in Figure B.1.
5.2 Minimum requirements
The following procedures shall be followed.
a) Keep the filter at < 40 °C. Avoid condensation on the filter.
1) Porapak PS is an example of a suitable product available commercially. This information is given for the convenience of users of this
part of ISO 11338 and does not constitute an endorsement by ISO of this product.
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ISO 11338-1:2003(E)
b) Include a solid-adsorber stage downstream of the filter if volatile PAH are to be reported.
3
c) Change the filter and solid-adsorber unit for cleaning the dilution air after a gas volume of 100 m has
been sampled.
5.3 Preparation and sampling
5.3.1 Sampling train and its operation
The unit for sampling a given quantity of partial flue gas consists of a nozzle, an elbow joint, and the probe.
The nozzle used shall have an effective diameter of between 6 mm and 30 mm. Choose the correct nozzle
size, in accordance with ISO 12141 or ISO 9096, to ensure isokinetic sampling is possible. Heat the probe to
the same temperature as the flue gas; this prevents any changes in the PAH due to temperature increases as
well as any change in the state of aggregation of the sample gas components. Measure the sampled gas
temperature at the exit from the probe and control the temperature of the probe by use of a thermostat.
Sampling probes with a diameter of 8 mm to 10 mm are used; the diameter of the probe is dependent on the
dimensions of the flue gas channel. The heat output of the probe is 250 W/m to 500 W/m, depending on the
tube length and extent of insulation.
In the mixing chamber the flue gas is mixed turbulently with dry ambient air. This dilution air enters at right
angles to the direction of flow of the sampled flue gas, and is first deflected by the walls of the chamber and
then mixes with the flue gas, which has passed through an insulated tube (8 mm to 10 mm long) which
projects into the chamber. The gas-mixing zone is 150 mm long and has a diameter of 50 mm.
The sample filter is located at the exit of the mixing chamber, and the dilution-air filter is located at the entry to
the mixing chamber. The filters are mounted in two-part filter casings, sealed with O-rings and then fixed with
snap closures to the mixing channel. Solid adsorbers may be linked downstream of both filters if the
measurement of 2- or 3-ring PAHs is required. The filter casings contain sensors for measuring the
temperature of the diluted sampling gas stream and the dilution air.
The sampling filter casing is connected with a flexible hose to a unit which measures the total flowrate of the
sampled flue gas and the dilution air. The flow of dilution air is measured before the dilution air filter casing by
a similar unit. The measurement of the flowrates is carried out by measuring the pressure drop across orifice
plates and the absolute pressure and by Pt-100 temperature sensors. Other calibrated suitable flowrate-
measuring devices may be used. The dimensions of the orifice plates are such that the ratio of the orifice
2
diameter (d) to the plate diameter (D) is (d/D) = 0,56. The calibration constants for the orifice plates are
determined at suitable intervals at the laboratory and then checked by operating the two nozzles from a
sampler in series.
The regulation of the sample flowrate to ensure isokinetic sampling can be fully automatic via a
microprocessor-controlled evaluation and control unit; but manual operation is also possible as long as the
flow is adjusted at least every 10 min. The automatic control system ensures that the sample gas flowrate is
maintained at isokinetic conditions and the filter temperature does not exceed 40 °C. The initial values are set
before sampling, based on temperature, pressure and gas velocity in the flue gas duct and in both flow
measurement units, as well as the composition of the flue gas. The theoretical value for sample gas flowrate is
then calculated using the measured temperature, pressure and gas velocity in the flue gas duct and in both
flow measurement units at intervals of 1 s and, if appropriate, the sample and dilution air flowrates are then
altered automatically.
Measuring devices for pressure, temperature, flue gas velocity and flue gas composition, especially moisture,
are required.
2)
A vacuum pump, a blower or a compressed-air-driven ejector can be used for the suction.
2) A Roots blower is an example of a suitable product available commercially. This information is given for the convenience of users of
this part of ISO 11338 and does not constitute an endorsement by ISO of this product.
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ISO 11338-1:2003(E)
The dilution air is passed through a drying tower to reduce atmospheric moisture and cooled, if appropriate,
using a heat exchanger.
5.3.2 Preparation
Before sampling, an internal standard can be dissolved in methanol or acetone and uniformly distributed over
the filter surface and/or the solid adsorber. The filter shall not be used for sampling until at least 2 h after the
internal standard has been applied. The filter with the internal standard may be stored for several days if
protected from light at –7 °C.
Check the sampling system for leaks before the sampling probe is inserted into the flue gas duct. To check
the system for the absence of leaks, close with stoppers both the nozzle of the sampling probe and the fitting
by which air enters the drying tower. Turn on the suction aggregate to produce the lowest absolute pressure
within the sampler that will be used during sampling. Then close the shutoff valve. The measured leak volume
shall be less than 5 % of the sampling flow. If the leak is larger than this, steps shall be taken to identify and
eliminate the leak (which most often arises from a defective O-ring or from a loose screw connection).
Before sampling starts, check the experimental parameters and constants stored in the evaluation and control
unit, if one is used and, if necessary, alter to parameters valid for the next sampling process.
Then fit the probe in the flue gas channel, with the shutoff valve closed to prevent backward flow through the
sampler. Preheat the suction tube to the temperature of the flue gas, normally after the leak check has been
performed.
3
Replace the filter and the solid adsorber unit used to clean the dilution air after a volume of 100 m has
passed through them.
5.3.3 Sampling
Once the sampler nozzle has been placed at the correct initial sampling position within the duct, sampling can
start. Regulate the dilution sampler either by an automatic evaluation and control unit or by manual control. At
the start of the sampling process, set the dilution air to a maximum, open the shutoff valve and adjust the
valves controlling the dilution air and sampled flue gas very rapidly until the correct flue gas flowrate for
isokinetic sampling is established. Regulate the dilution air flowrate by the valve to give a temperature of
40 °C at the sampling filter (see manufacturers’ operation manual).
During the sampling procedure using an automatic control unit, the display screen shall show the temperature
at the sampling filter, the sample volume already aspirated, the aspirated partial gas stream and the
temperature, pressure, differential pressure, the flue gas streams and the cooling air as well as the total gas
stream (flue gas - cooling air) at differential intervals of 1 s. Similar parameters shall be recorded at intervals
of 10 min or less if manual control is carried out.
Sampling may be interrupted at any time and then continued with unchanged settings, e.g. for system
measurements, to incorporate the sampling probe in another measurement axis. Closing the shutoff valve and
shutting off the pump will terminate sampling. Depending on the automatic control unit used, the data obtained
can be printed out, stored or displayed.
The sampler is then disassembled and the sample filter and solid adsorber are removed and stored. The
sampling filter is protected from UV radiation, sealed in an air tight enclosure such as a polyethylene bag and
stored under cool conditions (– 7 °C) in the dark until required for extraction. The adsorbent is left in the
adsorbent cartridge which is closed off with glass stoppers and protected from light. The parts of the sampling
equipment train before the adsorbent cartridge which came into contact with flue gas shall be checked at the
conclusion of the measurements for deposits and cleaned, if necessary. Any residues shall be added to the
material to be analysed, to be extracted in conjunction with the filters.
After sampling, analyse the following parts:
filter;
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ISO 11338-1:2003(E)
solid adsorber;
rinsing solutions.
NOTE The dilution air filter and adsorbent can be analysed as a blank, to obtain information on any possible
contamination from the ambient air during sampling
6 Method B — (Heated) filter/condenser/adsorber method
6.1 Principle
Flue gas is drawn from the duct isokinetically through a nozzle and a heated sampling probe to a particle filter
in a heated enclosure. Keep the filter above the dewpoint of the flue gas but at a temperature no higher than
the duct temperature. If there is a high particle content in the sample gas, a cyclone or quartz wool cartridge
can be used upstream of the filter to prevent the filter being overloaded. A properly sealed quartz, glass or
titanium-lined suction probe shall be used. Pass either all, a known fraction, or a known amount of the flow,
through a condenser which is attached downstream of the filter to cool the sample gas to below 20 °C.
Capture gaseous PAH by condensation in impingers and/or adsorption on solid adsorbents downstream from
the condenser. As the flue gas cools in the condenser, moisture is collected. Sampler designs have been
used in which either the condensate is collected in a flask before the flue gas passes through the adsorber, or
the condensate and the gas pass through the adsorber and then to the condensate flask. No comparisons
between the two approaches are known at the time of writing.
3 3
The sample volume flowrate can be from 1 m /h to 6 m /h, depending on the design of the sampling train.
After sampling, rinse the sampling device and the adsorber or impinger solutions, depending on which is used,
and extract and analyse the filter and acetone/toluene washings.
A schematic representation of a tested sampling device is given in Figures B.2 and B.3.
6.2 Minimum requirements
The following proced
...
SLOVENSKI STANDARD
SIST ISO 11338-1:2004
01-junij-2004
(PLVLMHQHSUHPLþQLKYLURY±'RORþDQMHSOLQVNHLQWUGQHID]HSROLFLNOLþQLK
DURPDWVNLKRJOMLNRYRGLNRYGHO 9]RUþHQMH
Stationary source emissions -- Determination of gas and particle-phase polycyclic
aromatic hydrocarbons -- Part 1: Sampling
Émissions de sources fixes -- Détermination des hydrocarbures aromatiques
polycycliques sous forme gazeuse et particulaire -- Partie 1: Échantillonnage
Ta slovenski standard je istoveten z: ISO 11338-1:2003
ICS:
13.040.40 (PLVLMHQHSUHPLþQLKYLURY Stationary source emissions
SIST ISO 11338-1:2004 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST ISO 11338-1:2004
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SIST ISO 11338-1:2004
INTERNATIONAL ISO
STANDARD 11338-1
First edition
2003-06-01
Stationary source emissions —
Determination of gas and particle-phase
polycyclic aromatic hydrocarbons —
Part 1:
Sampling
Émissions de sources fixes — Détermination sous forme gazeuse et
particulaire des hydrocarbures aromatiques polycycliques —
Partie 1: Échantillonnage
Reference number
ISO 11338-1:2003(E)
©
ISO 2003
---------------------- Page: 3 ----------------------
SIST ISO 11338-1:2004
ISO 11338-1:2003(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.
© ISO 2003
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 2003 — All rights reserved
---------------------- Page: 4 ----------------------
SIST ISO 11338-1:2004
ISO 11338-1:2003(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope. 1
2 Normative references. 1
3 Terms and definitions. 2
4 Principles and minimum requirements for the three sampling methods . 2
4.1 Principles. 2
4.2 General minimum requirements for all sampling methods. 2
4.3 General preparation and sampling. 3
5 Method A — Dilution method. 4
5.1 Principle. 4
5.2 Minimum requirements. 4
5.3 Preparation and sampling. 5
6 Method B — (Heated) filter/condenser/adsorber method. 7
6.1 Principle. 7
6.2 Minimum requirements. 7
6.3 Preparation and sampling. 7
7 Method C — Cooled probed/adsorber method . 9
7.1 Principle. 9
7.2 Minimum requirements. 9
7.3 Preparation and sampling. 10
Annex A (informative) Applicability of the sampling methods . 12
Annex B (informative) Schematic presentations, dimensions and materials of some tested
sampling devices . 14
Bibliography . 25
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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 11338-1 was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 1, Stationary
source emissions.
ISO 11338 consists of the following parts, under the general title Stationary source emissions —
Determination of gas and particle-phase polycyclic aromatic hydrocarbons:
Part 1: Sampling
Part 2: Sample preparation, clean-up and determination
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Introduction
Polycyclic aromatic hydrocarbons (PAHs) are a group of aromatic hydrocarbons, some members of which are
probable and others possible human carcinogens. Human exposure to PAHs can occur via food, soil, water,
air and skin contact with materials containing PAHs. While PAH are formed in natural processes (e.g. forest
fires), man-made atmospheric emissions of these compounds originate from the combustion of coal, gas,
wood and oil, from a range of industrial processes such as coke production, aluminium smelting and from
vehicles.
The quantification of atmospheric releases of PAH from stationary sources is an important part of the
environmental impact assessment of certain industrial processes.
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SIST ISO 11338-1:2004
INTERNATIONAL STANDARD ISO 11338-1:2003(E)
Stationary source emissions — Determination of gas
and particle-phase polycyclic aromatic hydrocarbons —
Part 1:
Sampling
1 Scope
This part of ISO 11338 describes methods for the determination of the mass concentration of polycyclic
aromatic hydrocarbons (PAHs) in flue gas emissions from stationary sources such as aluminium smelters,
coke works, waste incinerators, power stations, and industrial and domestic combustion appliances.
This part of ISO 11338 describes three sampling methods, which are here regarded as of equivalent value,
and specifies the minimum requirements for effective PAH sampling. The three sampling methods are the
dilution method (A), the heated filter/condenser/adsorber method (B) and the cooled probe/adsorber
method (C). All three methods are based on representative isokinetic sampling, as the PAHs are commonly
associated with particles in flue gas.
Information is provided to assist in the choice of the appropriate sampling method for the measurement
application under consideration.
This part of ISO 11338 is not applicable to the sampling of fugitive releases of PAHs.
NOTE Methods for sample preparation, clean-up and analysis are described in ISO 11338-2 and are intended to be
combined with one of the sampling methods described in this part of ISO 11338 to complete the whole measurement
procedure.
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 4225:1994, Air quality — General aspects — Vocabulary
ISO 9096:1992, Stationary source emissions — Determination of concentration and mass flow rate of
particulate material in gas-carrying ducts — Manual gravimetric method
ISO 12141, Stationary source emissions — Determination of mass concentration of particulate matter (dust) at
low concentrations — Manual gravimetric method
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3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 4225 and the following apply.
3.1
chimney
stack or final exit duct on a stationary process used for the dispersion of residual process gases
3.2
mass concentration
concentration of a substance in an emitted flue gas, expressed in units of mass per cubic metre
3.3
polycyclic aromatic hydrocarbon
PAH
compound that contains two or more fused aromatic rings made up only of carbon and hydrogen atoms
3.4
stationary source emissions
gases emitted by a stationary plant or process and transported to a chimney for dispersion into the
atmosphere
4 Principles and minimum requirements for the three sampling methods
4.1 Principles
Devices for the three sampling methods, illustrated in Figure B.1 (Method A), Figures B.2 and B.3 (Method B)
and Figure B.7 (Method C), can be applied for the sampling of PAH from stationary sources. They are
regarded as likely to produce equivalent results, however no comparative trials have been published to
establish this.
In general, as PAHs are present in both the vapour phase and on particles, the PAHs are collected in several
parts of the sampling train: the particle filter, condensate flask and solid or liquid adsorber. The choice of the
sampling method depends on the measurement application (see Table A.1 and Table A.2).
The three sampling methods A, B and C are discussed in detail in Clauses 5, 6 and 7, respectively.
Annex A provides further information on the applicability of the sampling methods.
After extraction and clean-up, the PAH are quantified either by High Performance Liquid Chromatography
(HPLC) using a fluorescence detector, diode array or UV detector, or by GC-FID/MS (low or high resolution
MS). Applicable methods for preparation, clean-up and determination are described in ISO 11338-2.
4.2 General minimum requirements for all sampling methods
The following steps shall be carried out irrespective of the sampling method chosen.
a) Carry out isokinetic sampling at representative points in the duct cross-section, in accordance with
ISO 9096.
b) Before sampling, rinse the inside of the sampling device with acetone, dichloromethane or methanol and
then with toluene. Alternatively, immerse the parts in methanol and subject them to ultrasonic vibration for
2 h, and subsequently dry at 150 °C. Store these washings and analyse only if the results indicate that
the sampler could have been contaminated before sampling, for example if the results unexpectedly
exceed the relevant emission limit.
c) Carry out a leak check before every sampling procedure.
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If the joints in the equipment are of ground glass, any slight leak can be dealt with by wetting the joints
with a small amount of clean water. Greases should never be used for this purpose.
d) The minimum velocity in the sorbent bed shall be:
3
for XAD-2 (thickness 50 mm, volume 35 cm ): less than 34 cm/s;
3
for PU foam (thickness 50 mm, volume 98 cm ): less than 30 cm/s.
e) Check each batch of filters, solvents and reagents for preparation for background PAH levels.
f) The glass parts of the sampling devices shall be protected from light during and after sampling, cooled
after sampling and cleaned after the extraction procedure.
g) Clean the probe thoroughly after each sample is taken. Add the probe rinse to the rinse from the rest of
the sample.
h) If the probe is contaminated with particles which cannot be easily removed, wipe away the particles with a
quartz wool swab steeped in acetone. Extract this quartz wool swab together with the filter.
i) If the sampling device is cleaned at the measurement site for reuse there, the probe, the nozzle, the filter
casings and all other parts of the sampling apparatus which have been in contact with the sample gas
and so could still be contaminated shall, after cleaning to remove the sample, be rinsed with acetone,
dichloromethane or methanol and followed by a toluene rinse. As before, this sample shall be preserved
in case of concern about cross-contamination between samples.
j) Extract samples within 1 week and preferably within 24 h. Store the samples in the dark at – 7 °C.
4.3 General preparation and sampling
The following steps shall be carried out irrespective of the sampling method chosen.
a) Choose the sampling location with regard to the safety of the personnel, the suitability of the
measurement cross-section (in accordance with ISO 9096), accessibility and availability of electrical
power.
b) Before the sampling starts, determine the flue gas density, pressure, temperature and if possible the gas
composition. In addition, to ensure isokinetic conditions, determine the velocity and temperature profile
across the cross-section of the flue gas channel. Choose the correct size of the sampling probe nozzle
calculated from the flue gas velocity and the approximate maximum flowrate achievable through the
sampler to ensure that the sampler will be capable of isokinetic sampling at all the measurement points in
the duct cross-section.
c) The parts of the sampler which come into contact with the sample and which have been carefully cleaned
in the laboratory shall be
transported in clean boxes, all the components having been sealed carefully;
assembled in situ, carefully avoiding contact with the operator's fingers on the parts of the sampling
equipment which will later be in contact with the sample.
d) After sampling, store all materials containing sampled PAH under cooled conditions and protected from
light.
The following data shall be recorded during sampling:
sample volume (standard conditions);
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sample temperature (in the gas meter);
mean flue gas velocity;
diameter of the stack;
moisture content of the flue gas;
mean oxygen content of the flue gas during the sampling period;
static pressure and temperature in the stack;
sampling flowrate.
To provide an estimate of the contamination present in the sampler and sampling matrices before sampling
and as a result of sampler assembly and transport, an additional sampling unit may be taken to the sampling
location, rinsed and analysed. Unfortunately contamination incidents are random in their occurrence, and so
this will only provide an estimate of the blank values. As a result, subtraction should not take place. However,
results in which the contribution of this blank is substantial should be treated with caution.
NOTE In order to obtain information on the performance of the sampler, internal standards can be added to the
sampling equipment (e.g. on the filters or the adsorbent) and their recovery measured. However, the internal standards
are bound to the filter in a manner different to that by which the native PAHs are bound to the fly ash, so there may be
differences in behaviour during sampling and extraction.
5 Method A — Dilution method
5.1 Principle
A proportion of the flue gas is collected isokinetically via a sampling probe heated to the temperature of the
flue gas. The flue gas is cooled very rapidly to temperatures below 40 °C in a mixing chamber using dried,
filtered and, if appropriate, cooled air. This dilution prevents condensation of water present in the gas sample.
In addition, dilution seeks to minimize the reactions of the separated PAH with other flue gas components, e.g.
NO, NO , SO , SO and HCl. The sampling conditions are similar to the natural dilution and cooling
2 2 3
processes of flue gases emitted into the atmosphere.
The diluted flue gas is then passed through a silicone-bonded glass fibre filter impregnated with paraffin oil.
This retains PAH components with 4 to 7 rings. If sampling for more volatile PAHs (2- or 3-ring compounds) is
1)
required, a solid adsorbent can be incorporated downstream of the filter in the sampling train.
3 3
The sample gas flowrate through the sampling probe should be in the range of 2 m /h to 8 m /h. Normally
3 3
within 1,5 h of sampling, sufficient PAH for analysis has been collected, usually in about 8 m to 10 m . After
sampling, the filter and, if used, the solid adsorbent are extracted and analysed.
A schematic representation of a tested sampling device is given in Figure B.1.
5.2 Minimum requirements
The following procedures shall be followed.
a) Keep the filter at < 40 °C. Avoid condensation on the filter.
1) Porapak PS is an example of a suitable product available commercially. This information is given for the convenience of users of this
part of ISO 11338 and does not constitute an endorsement by ISO of this product.
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b) Include a solid-adsorber stage downstream of the filter if volatile PAH are to be reported.
3
c) Change the filter and solid-adsorber unit for cleaning the dilution air after a gas volume of 100 m has
been sampled.
5.3 Preparation and sampling
5.3.1 Sampling train and its operation
The unit for sampling a given quantity of partial flue gas consists of a nozzle, an elbow joint, and the probe.
The nozzle used shall have an effective diameter of between 6 mm and 30 mm. Choose the correct nozzle
size, in accordance with ISO 12141 or ISO 9096, to ensure isokinetic sampling is possible. Heat the probe to
the same temperature as the flue gas; this prevents any changes in the PAH due to temperature increases as
well as any change in the state of aggregation of the sample gas components. Measure the sampled gas
temperature at the exit from the probe and control the temperature of the probe by use of a thermostat.
Sampling probes with a diameter of 8 mm to 10 mm are used; the diameter of the probe is dependent on the
dimensions of the flue gas channel. The heat output of the probe is 250 W/m to 500 W/m, depending on the
tube length and extent of insulation.
In the mixing chamber the flue gas is mixed turbulently with dry ambient air. This dilution air enters at right
angles to the direction of flow of the sampled flue gas, and is first deflected by the walls of the chamber and
then mixes with the flue gas, which has passed through an insulated tube (8 mm to 10 mm long) which
projects into the chamber. The gas-mixing zone is 150 mm long and has a diameter of 50 mm.
The sample filter is located at the exit of the mixing chamber, and the dilution-air filter is located at the entry to
the mixing chamber. The filters are mounted in two-part filter casings, sealed with O-rings and then fixed with
snap closures to the mixing channel. Solid adsorbers may be linked downstream of both filters if the
measurement of 2- or 3-ring PAHs is required. The filter casings contain sensors for measuring the
temperature of the diluted sampling gas stream and the dilution air.
The sampling filter casing is connected with a flexible hose to a unit which measures the total flowrate of the
sampled flue gas and the dilution air. The flow of dilution air is measured before the dilution air filter casing by
a similar unit. The measurement of the flowrates is carried out by measuring the pressure drop across orifice
plates and the absolute pressure and by Pt-100 temperature sensors. Other calibrated suitable flowrate-
measuring devices may be used. The dimensions of the orifice plates are such that the ratio of the orifice
2
diameter (d) to the plate diameter (D) is (d/D) = 0,56. The calibration constants for the orifice plates are
determined at suitable intervals at the laboratory and then checked by operating the two nozzles from a
sampler in series.
The regulation of the sample flowrate to ensure isokinetic sampling can be fully automatic via a
microprocessor-controlled evaluation and control unit; but manual operation is also possible as long as the
flow is adjusted at least every 10 min. The automatic control system ensures that the sample gas flowrate is
maintained at isokinetic conditions and the filter temperature does not exceed 40 °C. The initial values are set
before sampling, based on temperature, pressure and gas velocity in the flue gas duct and in both flow
measurement units, as well as the composition of the flue gas. The theoretical value for sample gas flowrate is
then calculated using the measured temperature, pressure and gas velocity in the flue gas duct and in both
flow measurement units at intervals of 1 s and, if appropriate, the sample and dilution air flowrates are then
altered automatically.
Measuring devices for pressure, temperature, flue gas velocity and flue gas composition, especially moisture,
are required.
2)
A vacuum pump, a blower or a compressed-air-driven ejector can be used for the suction.
2) A Roots blower is an example of a suitable product available commercially. This information is given for the convenience of users of
this part of ISO 11338 and does not constitute an endorsement by ISO of this product.
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The dilution air is passed through a drying tower to reduce atmospheric moisture and cooled, if appropriate,
using a heat exchanger.
5.3.2 Preparation
Before sampling, an internal standard can be dissolved in methanol or acetone and uniformly distributed over
the filter surface and/or the solid adsorber. The filter shall not be used for sampling until at least 2 h after the
internal standard has been applied. The filter with the internal standard may be stored for several days if
protected from light at –7 °C.
Check the sampling system for leaks before the sampling probe is inserted into the flue gas duct. To check
the system for the absence of leaks, close with stoppers both the nozzle of the sampling probe and the fitting
by which air enters the drying tower. Turn on the suction aggregate to produce the lowest absolute pressure
within the sampler that will be used during sampling. Then close the shutoff valve. The measured leak volume
shall be less than 5 % of the sampling flow. If the leak is larger than this, steps shall be taken to identify and
eliminate the leak (which most often arises from a defective O-ring or from a loose screw connection).
Before sampling starts, check the experimental parameters and constants stored in the evaluation and control
unit, if one is used and, if necessary, alter to parameters valid for the next sampling process.
Then fit the probe in the flue gas channel, with the shutoff valve closed to prevent backward flow through the
sampler. Preheat the suction tube to the temperature of the flue gas, normally after the leak check has been
performed.
3
Replace the filter and the solid adsorber unit used to clean the dilution air after a volume of 100 m has
passed through them.
5.3.3 Sampling
Once the sampler nozzle has been placed at the correct initial sampling position within the duct, sampling can
start. Regulate the dilution sampler either by an automatic evaluation and control unit or by manual control. At
the start of the sampling process, set the dilution air to a maximum, open the shutoff valve and adjust the
valves controlling the dilution air and sampled flue gas very rapidly until the correct flue gas flowrate for
isokinetic sampling is established. Regulate the dilution air flowrate by the valve to give a temperature of
40 °C at the sampling filter (see manufacturers’ operation manual).
During the sampling procedure using an automatic control unit, the display screen shall show the temperature
at the sampling filter, the sample volume already aspirated, the aspirated partial gas stream and the
temperature, pressure, differential pressure, the flue gas streams and the cooling air as well as the total gas
stream (flue gas - cooling air) at differential intervals of 1 s. Similar parameters shall be recorded at intervals
of 10 min or less if manual control is carried out.
Sampling may be interrupted at any time and then continued with unchanged settings, e.g. for system
measurements, to incorporate the sampling probe in another measurement axis. Closing the shutoff valve and
shutting off the pump will terminate sampling. Depending on the automatic control unit used, the data obtained
can be printed out, stored or displayed.
The sampler is then disassembled and the sample filter and solid adsorber are removed and stored. The
sampling filter is protected from UV radiation, sealed in an air tight enclosure such as a polyethylene bag and
stored under cool conditions (– 7 °C) in the dark until required for extraction. The adsorbent is left in the
adsorbent cartridge which is closed off with glass stoppers and protected from light. The parts of the sampling
equipment train before the adsorbent cartridge which came into contact with flue gas shall be checked at the
conclusion of the measurements for deposits and cleaned, if necessary. Any residues shall be added to the
material to be analysed, to be extracted in conjunction with the filters.
After sampling, analyse the following parts:
filter;
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solid adsorber;
rinsing solutions.
NOTE The dilution air filter and adsorbent can be analysed as a blank, to obtain information on any possible
contamination from the ambient air during sampling
6 Method B — (Heated) filter/condenser/adsorber method
6.1 Principle
Flue gas is drawn from the duct isokinetically through a nozzle and a heated sampling probe to a particle filter
in a heated enclosure. Keep the filter above the dewpoint of the flue gas but at a temperature no higher than
the duct temperature. If there is a high particle content in the sample gas, a cyclone or quartz wool cartridge
can be u
...
NORME ISO
INTERNATIONALE 11338-1
Première édition
2003-06-01
Émissions de sources fixes —
Détermination des hydrocarbures
aromatiques polycycliques sous forme
gazeuse et particulaire —
Partie 1:
Échantillonnage
Stationary source emissions — Determination of gas and particle-phase
polycyclic aromatic hydrocarbons —
Part 1: Sampling
Numéro de référence
ISO 11338-1:2003(F)
©
ISO 2003
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ISO 11338-1:2003(F)
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© ISO 2003
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Publié en Suisse
ii © ISO 2003 – Tous droits réservés
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ISO 11338-1:2003(F)
Sommaire Page
Avant-propos. iv
Introduction . v
1 Domaine d'application. 1
2 Références normatives. 1
3 Termes et définitions . 1
4 Principes et exigences minimales pour les trois méthodes d'échantillonnage. 2
4.1 Principes . 2
4.2 Exigences minimales générales applicables à l'ensemble des méthodes
d'échantillonnage. 2
4.3 Préparations d'ordre général et échantillonnage . 3
5 Méthode A — Méthode de dilution . 4
5.1 Principe . 4
5.2 Exigences minimales. 5
5.3 Préparation et échantillonnage . 5
6 Méthode B — Méthode de filtre/condenseur/adsorbant (avec chauffage). 7
6.1 Principe . 7
6.2 Exigences minimales. 8
6.3 Préparation et échantillonnage . 8
7 Méthode C — Méthode de sondage/adsorption avec refroidissement . 10
7.1 Principe . 10
7.2 Exigences minimales. 10
7.3 Préparation et échantillonnage . 10
Annexe A (informative) Applicabilité des méthodes d'échantillonnage . 13
Annexe B (informative) Représentations schématiques, dimensions et matériaux de certains
dispositifs d'échantillonnage soumis à l'essai. 15
Bibliographie . 26
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ISO 11338-1:2003(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 11338-1 a été élaborée par le comité technique ISO/TC 146, Qualité de l'air, sous-comité SC 1,
Émissions de sources fixes.
L'ISO 11338 comprend les parties suivantes, présentées sous le titre général Émissions de sources fixes —
Détermination des hydrocarbures aromatiques polycycliques sous forme gazeuse et particulaire:
Partie 1: Échantillonnage
Partie 2: Préparation des échantillons, purification et détermination
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ISO 11338-1:2003(F)
Introduction
Les hydrocarbures aromatiques polycycliques (HAP) font partie du groupe des hydrocarbures aromatiques.
Certains membres de ce groupe sont probablement des carcinogènes pour l'homme et d'autres sont
considérés comme des carcinogènes potentiels. L'exposition humaine aux HAP peut se produire via la
nourriture, le sol, l'eau, l'air et par le contact de la peau avec des matériaux en contenant. Les HAP se forment
de façon naturelle (par exemple lors de feux de forêt), mais certaines émissions atmosphériques, engendrées
par l'homme, de ces composés proviennent de la combustion de charbon, de gaz, de bois et de pétrole, de
certains processus industriels tels que la production de coke, la fonte d'aluminium et des véhicules.
La quantification des émissions de HAP dans l'atmosphère à partir de sources fixes représente un aspect
important de l'évaluation de l'impact de certains processus industriels sur l'environnement.
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NORME INTERNATIONALE ISO 11338-1:2003(F)
Émissions de sources fixes — Détermination des
hydrocarbures aromatiques polycycliques sous forme gazeuse
et particulaire —
Partie 1:
Échantillonnage
1 Domaine d'application
La présente partie de l'ISO 11338 décrit des méthodes de détermination de la concentration massique des
hydrocarbures aromatiques polycycliques (HAP) dans les émissions d'effluents gazeux provenant de sources
fixes telles que les creusets d'aluminium, les cokeries, les incinérateurs de déchets, les centrales électriques
et les installations industrielles et domestiques.
La présente partie de l'ISO 11338 décrit trois méthodes d'échantillonnage, considérées ici comme
équivalentes, et spécifie les exigences minimales qui s'appliquent à l'échantillonnage effectif des HAP. Les
trois méthodes d'échantillonnage sont la méthode de dilution (A), la méthode de
filtration/condensation/adsorption avec chauffage (B) et la méthode de sondage/adsorption avec
refroidissement (C). Les trois méthodes sont basées sur un échantillonnage isocinétique représentatif car les
HAP sont en général associés à des particules dans des effluents gazeux.
Des informations sont fournies pour aider au choix de la méthode d'échantillonnage appropriée pour
l'application considérée.
La présente partie de l'ISO 11338 n'est pas applicable à l'échantillonnage des émissions fugitives de HAP.
NOTE Les méthodes de préparation des échantillons, de purification et d'analyse sont décrites dans l'ISO 11338-2 et
sont à combiner avec l'une des méthodes d'échantillonnage décrites dans la présente partie de l'ISO 11338 pour mener à
bien l'ensemble du mode opératoire de mesurage.
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 4225:1994, Qualité de l'air — Aspects généraux — Vocabulaire
ISO 9096:1992, Émissions de sources fixes — Détermination de la concentration et du débit-masse de
matières particulaires dans des veines gazeuses — Méthode gravimétrique manuelle
ISO 12141, Émissions de sources fixes — Détermination d’une faible concentration en masse de matières
particulaires (poussières) — Méthode gravimétrique manuelle
3 Termes et définitions
Pour les besoins du présent document, les termes et définitions suivants, ainsi que ceux donnés dans
l'ISO 4225, s'appliquent.
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ISO 11338-1:2003(F)
3.1
cheminée
conduit de rejet final d'une source fixe utilisé pour la dispersion des gaz résiduels d'un processus industriel
3.2
concentration en masse
concentration massique
concentration d'une substance dans un effluent gazeux émis, exprimée en unités de masse par mètre cube
3.3
hydrocarbure aromatique polycyclique
HAP
composé contenant au moins deux cycles aromatiques condensés constitués seulement d'atomes de carbone
et d'atomes d'hydrogène
3.4
émissions de sources fixes
gaz émis par une usine ou une installation fixe, évacués dans l'atmosphère par une cheminée
4 Principes et exigences minimales pour les trois méthodes d'échantillonnage
4.1 Principes
Les dispositifs pour les trois méthodes d'échantillonnage présentées à la Figure B.1 (Méthode A), aux
Figures B.2 et B.3 (Méthode B) et à la Figure B.7 (Méthode C) peuvent être utilisés pour l'échantillonnage des
HAP provenant de sources fixes. Ils sont considérés comme pouvant fournir des résultats équivalents bien
qu'aucun essai comparatif n'ait été publié pour établir ce fait.
En règle générale, comme les HAP sont présents à la fois dans la phase gazeuse et sur des particules, ils
sont recueillis dans différents éléments de l'équipement de prélèvement: le filtre à particules, la fiole à
condensats et l'unité d'adsorption (solide) ou d'absorption (liquide). Le choix de la méthode d'échantillonnage
dépend de l'application de mesurage (voir Tableau A.1 et Tableau A.2).
Les trois méthodes d'échantillonnage A, B et C sont respectivement décrites en détail dans les Articles 5, 6
et 7.
L'Annexe A fournit des informations complémentaires en ce qui concerne l'applicabilité des méthodes
d'échantillonnage.
Après l'extraction et la purification, les HAP sont quantifiés soit par chromatographie en phase liquide à haute
performance (HPLC) avec un détecteur de fluorescence, un détecteur à barrette de diodes ou un détecteur
d'UV, soit par chromatographie en phase gazeuse, avec un détecteur à ionisation de flamme, couplée à un
spectromètre de masse (spectrométrie de masse haute ou basse résolution). Les méthodes applicables à la
préparation, à la purification et à la détermination sont décrites dans l'ISO 11338-2.
4.2 Exigences minimales générales applicables à l'ensemble des méthodes
d'échantillonnage
Les étapes suivantes doivent être effectuées quelle que soit la méthode d'échantillonnage choisie.
a) Effectuer l'échantillonnage isocinétique en des points représentatifs d'une section tranversale du conduit,
conformément à l'ISO 9096.
b) Avant l'échantillonnage, rincer l'intérieur du dispositif d'échantillonnage avec de l'acétone, du
dichlorométhane ou du méthanol, puis avec du toluène. Comme alternative, plonger les pièces dans le
méthanol, et les soumettre à des vibrations par ultrasons pendant 2 h, après quoi les sécher à 150 °C.
Stocker les bains de rinçage et ne procéder à l'analyse que lorsque les résultats indiquent que
l'échantillonneur a pu être contaminé avant l'échantillonnage, par exemple en cas de résultats dépassant
de façon inattendue la limite d'émission attendue.
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c) Effectuer un contrôle d'étanchéité avant chaque processus d'échantillonnage.
Si les joints du dispositif sont en verre rodé, il est possible de remédier aux fuites peu importantes par
humidification des joints avec un peu d'eau propre. Il convient de ne jamais utiliser de graisse dans ce cas.
d) La vitesse minimale dans la couche d'adsorbant doit être
3
inférieure à 34 cm/s pour la résine XAD-2 (épaisseur 50 mm, volume 35 cm );
3
inférieure à 30 cm/s pour la mousse de polyuréthanne (PUF) (épaisseur 50 mm, volume 98 cm ).
e) Contrôler les niveaux de blancs de HAP de chaque lot de filtres, de solvants et de réactifs de la
préparation.
f) Protéger les parties en verre des dispositifs d'échantillonnage de la lumière pendant et après le
prélèvement, les refroidir après l'échantillonnage et les nettoyer après le processus d'extraction.
g) Nettoyer soigneusement la sonde après chaque prélèvement d'échantillon. Ajouter le rinçage de la sonde
au rinçage du reste de l'échantillon.
h) Si la sonde est contaminée par des particules dont l'élimination est difficile, retirer ces dernières à l'aide
d'un tampon en laine de quartz trempé dans de l'acétone. Extraire ce tampon de laine de quartz en
même temps que le filtre.
i) Si le dispositif d'échantillonnage est nettoyé sur le site de mesurage pour réutilisation ultérieure, la sonde,
la buse, les porte-filtres et les autres pièces de l'appareillage de prélèvement qui ont été en contact avec
le gaz échantillon et qui sont donc susceptibles d'être contaminés, doivent, après le nettoyage suivant le
prélèvement de l'échantillon, être rincés avec de l'acétone, du dichlorométhane ou du méthanol, puis
avec du toluène. Comme il a été évoqué plus haut, cet échantillon doit être conservé en cas de problème
de contamination croisée entre échantillons.
j) Extraire les échantillons dans un délai d'une semaine et, de préférence, dans les 24 h. Stocker les
échantillons à l'abri de la lumière à la température de -7 °C.
4.3 Préparations d'ordre général et échantillonnage
Les étapes suivantes doivent être effectuées quelle que soit la méthode d'échantillonnage choisie.
a) Choisir l'emplacement d'échantillonnage en prenant en compte la sécurité du personnel, l'adaptation de
la section transversale de mesurage (conformément à l'ISO 9096) l'accessibilité et la disponibilité d'une
alimentation électrique.
b) Avant de commencer l'échantillonnage, déterminer la masse volumique, la pression et la température de
l'effluent gazeux et, si possible, la composition du gaz. En outre, pour garantir des conditions
isocinétiques, déterminer le profil de la vitesse et de la température au niveau de la section transversale
du conduit d'effluent gazeux. Choisir la dimension correcte pour la buse de la sonde d'échantillonnage
calculée en fonction de la vitesse des effluents gazeux et du débit maximal approximatif susceptibles
d'être atteints au niveau de l'échantillonneur, pour garantir que celui-ci sera en mesure d'effectuer des
échantillonnages isocinétiques en tous les points de mesurage de la section transversale du conduit de
gaz.
c) Les pièces de l'échantillonneur qui seront en contact avec l'échantillon et ayant été soigneusement
nettoyées en laboratoire doivent être
transportées dans des boîtes propres et les composants placés dans des emballages hermétiques;
assemblées in situ, en prenant soin d'éviter tout contact des doigts de l'opérateur avec les différentes
pièces de l'équipement d'échantillonnage qui seront plus tard en contact avec l'éprouvette.
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d) Une fois l'échantillonnage terminé, stocker tous les matériaux contenant des hydrocarbures aromatiques
polycycliques échantillonnés au frais et à l'abri de la lumière.
Au cours de l'échantillonnage, les données suivantes doivent être consignées:
le volume de l'échantillon (conditions normalisées);
la température de l'échantillon (dans le débitmètre);
la vitesse moyenne des effluents gazeux;
le diamètre de la cheminée;
la teneur en eau des effluents gazeux;
la teneur moyenne en oxygène des effluents gazeux pendant la période d'échantillonnage;
la pression statique et la température dans la cheminée;
le débit de l'échantillonnage.
Pour obtenir une estimation de la contamination de l'échantillonneur et des matrices d'échantillonnage avant
l'échantillonnage, et à la suite de l'assemblage et du transport de l'échantillonneur, il est possible d'apporter
un autre appareil d'échantillonnage sur place, de le rincer et d'analyser le rinçage. Malheureusement, les
incidents de contamination sont aléatoires et le résultat obtenu fournira seulement une estimation des valeurs
de blanc. Par conséquent, il n'est pas recommandé de faire la soustraction. Cependant, il convient de traiter
avec précaution les résultats dans lesquels la contribution du blanc est conséquente.
NOTE Pour obtenir des informations sur les performances de l'échantillonneur, des étalons internes peuvent être
ajoutés à l'équipement d'échantillonnage (c'est-à-dire sur les filtres ou l'adsorbant) et leur taux de récupération mesuré.
Cependant, le lien existant entre les étalons internes et le filtre sera différent du lien existant entre les HAP d'origine et les
cendres volantes. Par conséquent, des différences de comportement peuvent survenir lors de l'échantillonnage et de
l'extraction.
5 Méthode A — Méthode de dilution
5.1 Principe
Une certaine quantité d'effluent gazeux est collectée de façon isocinétique via une sonde d'échantillonnage
chauffée à la température de l'effluent gazeux. L'effluent gazeux est très rapidement porté à une température
inférieure à 40 °C dans une chambre de mélange utilisant de l'air sec filtré et, le cas échéant, refroidi. Cette
dilution empêche la condensation de l'eau présente dans l'échantillon de gaz. En outre, elle permet de réduire
les réactions entre les hydrocarbures aromatiques polycycliques ainsi séparés et les autres composants
d'effluent gazeux (par exemple NO, NO , SO , SO et HCl). Les conditions d'échantillonnage sont similaires
2 2 3
aux processus de dilution et de refroidissement naturels des effluents gazeux émis dans l'atmosphère.
L'effluent gazeux dilué passe ensuite dans un filtre en fibre de verre siliconé imprégné d'huile de paraffine.
Cette opération permet de retenir les composants de HAP contenant 4 à 7 cycles. Si un échantillonnage de
1)
HAP plus volatils (2 ou 3 cycles) est requis, un adsorbant solide peut être incorporé en aval du filtre dans
l'appareillage de prélèvement.
1) Porapak PS est un exemple de produit approprié disponible sur le marché. Cette information est donnée à l'intention
des utilisateurs de la présente Norme internationale et ne signifie nullement que l'ISO approuve ou recommande l'emploi
exclusif du produit ainsi désigné.
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3 3
Il convient que le débit du gaz d'échantillonnage dans la sonde soit compris entre 2 m /h et 8 m /h. En règle
générale, un échantillonnage de 1,5 h permet de collecter suffisamment de HAP pour analyse dans un
3 3
volume d'environ 8 m à 10 m . Après l'échantillonnage, le filtre et, le cas échéant, l'adsorbant solide sont
prélevés et analysés.
La Figure B.1 donne une représentation schématique d'un dispositif d'échantillonnage soumis à l'essai.
5.2 Exigences minimales
Les procédures suivantes doivent être respectées.
a) Conserver le filtre à une température inférieure à 40 °C. Éviter la condensation sur le filtre.
b) Incorporer un adsorbant solide en aval du filtre lorsque la présence de HAP volatils doit être consignée.
c) Changer le filtre et l'unité d'adsorption solide permettant le nettoyage de l'air de dilution après
3
échantillonnage de 100 m de gaz.
5.3 Préparation et échantillonnage
5.3.1 Appareillage de prélèvement et fonctionnement
L'appareil permettant d'échantillonner une quantité donnée d'effluent gazeux partiel se compose d'une buse,
d'un coude et d'une sonde. La buse utilisée doit avoir un diamètre effectif compris entre 6 mm et 30 mm.
Choisir une taille de buse conformément à l'ISO 12141 ou à l'ISO 9096, permettant d'assurer un
échantillonnage isocinétique. Chauffer la sonde à la même température que l'effluent gazeux. Cela permet
d'éviter des modifications des HAP dues à une augmentation de la température, et des modifications de l'état
d'agrégation des composants gazeux de l'échantillon. Mesurer la température du gaz échantillonné en sortie
de la sonde et contrôler la température de la sonde à l'aide d'un thermostat. Des sondes d'échantillonnage
d'un diamètre de 8 mm à 10 mm sont utilisées, et leur diamètre dépend des dimensions du conduit d'effluent
gazeux. La perte de chaleur de la sonde est de 250 W/m à 500 W/m, selon la longueur du tube et le degré
d'isolation.
Dans la chambre de mélange, l'effluent gazeux est mélangé par turbulence avec de l'air ambiant séché. L'air
de dilution entre perpendiculairement à la direction du flux de l'effluent gazeux échantillonné. Dans un premier
temps, il est dévié par les parois de la chambre de mélange, puis il se mélange avec l'effluent gazeux qui,
après être passé dans un tube isolé (de 8 mm à 10 mm de long), s'est trouvé projeté dans la chambre de
mélange. La zone de mélange de gaz mesure 150 mm de long et son diamètre est de 50 mm.
Le filtre échantillon est placé en sortie de la chambre de mélange et le filtre d'air de dilution, en entrée. Les
filtres sont montés dans des porte-filtres en deux parties, rendus étanches par des joints toriques puis fixés à
la chambre de mélange par des clips. Des adsorbants solides peuvent être placés en aval des deux filtres
lorsque des mesurages de HAP de 2 ou 3 cycles sont requis. Les porte-filtres contiennent des capteurs
permettant de mesurer la température du flux de gaz d'échantillonnage dilué et de l'air de dilution.
Le porte-filtre d'échantillonnage est relié par un tuyau souple à un appareil qui mesure le débit total de
l'effluent gazeux échantillonné et de l'air de dilution. Le débit de l'air de dilution est mesuré en amont du
porte-filtre par un appareil similaire. Le débit est obtenu en mesurant la dépression au niveau des
diaphragmes et la pression absolue et en utilisant des capteurs de température Pt-100. D'autres appareils de
mesurage de débit étalonnés et appropriés peuvent être utilisés. Les dimensions des diaphragmes sont telles
2
que le rapport du diamètre de l'orifice (d) au diamètre du diaphragme (D) est (d/D) = 0,56. Les constantes
d'étalonnage des diaphragmes sont déterminées à intervalles appropriés en laboratoire, puis contrôlées à
l'aide de deux buses d'échantillonneur fonctionnant en série.
La régulation du débit de l'échantillon permettant d'assurer un échantillonnage isocinétique peut être
complètement automatisée à l'aide d'une unité de régulation automatique par microprocesseur, mais elle peut
également être effectuée manuellement tant que le débit est ajusté à des intervalles de 10 min au maximum.
Le système de régulation automatique garantit que le débit du gaz échantillon est maintenu à des conditions
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ISO 11338-1:2003(F)
isocinétiques et que la température du filtre ne dépasse pas 40 °C. Les valeurs initiales sont définies avant
l'échantillonnage, d'une part, en fonction de la température, de la pression et de la vitesse du gaz à l'intérieur
du conduit d'effluent gazeux et dans les deux appareils de mesurage du débit, et, d'autre part, en fonction de
la composition de l'effluent gazeux. La valeur théorique du débit de gaz de l'échantillon est ensuite calculée à
l'aide de la température, de la pression et de la vitesse du gaz mesurées dans le conduit d'effluent gazeux et
dans les deux appareils de mesurage du débit, à des intervalles de 1 s et, le cas échéant, les débits de
l'échantillon et de l'air de dilution sont automatiquement modifiés.
Les appareils de mesurage sont requis pour déterminer les paramètres suivants: pression, température,
vitesse et composition des effluents gazeux (et notamment, leur teneur en eau).
2)
Une pompe à vide, une pompe ou une pompe à éjecteur à air comprimé peuvent être utilisées pour
l'aspiration.
L'air de dilution passe par une tour de séchage permettant de réduire la teneur en eau de l'atmosphère et est
refroidi, le cas échéant, à l'aide d'un échangeur thermique.
5.3.2 Préparations
Avant l'échantillonnage, un étalon interne peut être dissous dans du méthanol ou de l'acétone et réparti
uniformément sur la surface du filtre et/ou sur l'adsorbant solide. Le filtre pour échantillonnage ne doit pas être
utilisé avant un délai de 2 h minimum après application de l'étalon interne. Le filtre avec étalon interne peut
être stocké pendant plusieurs jours à l'abri de la lumière et à la température de -7 °C.
Contrôler l'étanchéité du système d'échantillonnage avant insertion de la sonde d'échantillonnage dans le
conduit d'effluent gazeux. Pour vérifier l'absence de fuite, obturer à l'aide de bouchons la buse de la sonde
d'échantillonnage et le dispositif par lequel l'air rentre dans la tour de séchage. Mettre le dispositif d'aspiration
en route pour atteindre la pression absolue la plus faible à l'intérieur de l'échantillonneur qui sera utilisé
pendant le prélèvement. Puis fermer le robinet d'arrêt. Il faut que le volume de fuite mesuré soit inférieur à
5 % du débit d'échantillonnage. Si la fuite est supérieure à ce chiffre, des mesures doivent être prises pour
identifier et éliminer la fuite (qui, le plus souvent, a pour origine un joint torique défectueux ou des vis
insuffisamment serrées).
Avant le début de l'échantillonnage, vérifier les paramètres d'expérimentation et les constantes
éventuellement utilisés, stockés dans l'unité de régulation, et, si nécessaire, les modifier pour en faire des
paramètres valides pour le processus d'échantillonnage suivant.
Placer ensuite la sonde dans le conduit d'effluent gazeux et fermer le robinet d'arrêt pour éviter une
contre-pression dans l'échantillonneur. Préchauffer le tube d'aspiration à la température de l'effluent gazeux,
en règle générale après que le contrôle de l'étanchéité a été effectué.
Remplacer le filtre et l'unité d'adsorption solide utilisés pour nettoyer l'air de dilution lorsqu'ils ont traité un
3
volume de 100 m .
5.3.3 Échantillonnage
Une fois la buse de l'échantillonneur placée à l'emplacement d'échantillonnage initial correct à l'intérieur du
conduit, le prélèvement peut commencer. Réguler l'échantillonneur de dilution soit par une unité automatique
de régulation, soit manuellement. Au
...
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