EN ISO 16017-1:2000

SLOVENSKI STANDARD
01-maj-2002
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Indoor, ambient and workplace air - Sampling and analysis of volatile organic
compounds by sorbent tube/thermal desorption/capillary gas chromatography - Part 1:
Pumped sampling (ISO 16017-1:2000)
Innenraumluft, Außenluft und Luft am Arbeitsplatz - Probenahme und Analyse flüchtiger
organischer Verbindungen durch Sorptionsröhrchen/thermische Desorption/Kapillar-
Gaschromatographie - Teil 1: Probenahme mit einer Pumpe

(ISO 16017-1:2000)
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 1: Echantillonnage par pompage (ISO 16017-
1:2000)
Ta slovenski standard je istoveten z: EN ISO 16017-1:2000
ICS:
13.040.01 Kakovost zraka na splošno Air quality in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

INTERNATIONAL ISO
STANDARD 16017-1
First edition
2000-11-15
Indoor, ambient and workplace air —
Sampling and analysis of volatile organic
compounds by sorbent tube/thermal
desorption/capillary gas
chromatography —
Part 1:
Pumped 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 1: Échantillonnage par pompage
Reference number
ISO 16017-1:2000(E)
©
ISO 2000
ISO 16017-1:2000(E)
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ii © ISO 2000 – All rights reserved

ISO 16017-1:2000(E)
Contents Page
Foreword.iv
1 Scope .1
2 Normative references .2
3 Terms and definitions .2
4 Principle.3
5 Reagents and materials .3
6 Apparatus .5
7 Sample tube conditioning.6
8 Calibration of pump.7
9 Sampling.7
10 Procedure .8
10.1 Safety precautions.8
10.2 Desorption and analysis .8
10.3 Calibration .9
10.4 Determination of sample concentration.10
10.5 Determination of desorption efficiency.10
11 Calculations.10
11.1 Mass concentration of analyte .10
11.2 Volume concentration of analyte .11
12 Interferences .11
13 Performance characteristics .11
14 Test report .12
15 Quality control.12
Annex A (normative) Determination of breakthrough volumes from gas standards.21
Annex B (normative) Determination of breakthrough volume from the extrapolated retention volume.22
Annex C (informative) Description of sorbent types .23
Annex D (informative) Guidance on sorbent selection .24
Annex E (informative) Guidance on sorbent use .25
Annex F (informative) Summary of data on overall uncertainty, precision, bias and storage.26
Bibliography.28
ISO 16017-1:2000(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 3.
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 part of ISO 16017 may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
International Standard ISO 16017-1 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
Annexes A and B form a normative part of this part of ISO 16017. Annexes C through F are for information only.
iv © ISO 2000 – All rights reserved

INTERNATIONAL STANDARD ISO 16017-1:2000(E)
Indoor, ambient and workplace air — Sampling and analysis of
volatile organic compounds by sorbent tube/thermal
desorption/capillary gas chromatography —
Part 1:
Pumped 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 ambient, indoor and workplace atmospheres and the assessment of emissions from
materials in small- or full-scale test chambers.
This part of ISO 16017 is appropriate for a wide range of VOCs, including hydrocarbons, halogenated hydro-
1)
carbons, 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 will generally require
derivatization, very low boiling compounds will only be partially retained by the sorbents, depending on ambient
temperature, and can only be estimated qualitatively. Semi-volatile compounds will be fully retained by the
sorbents, but may only be partially recovered. Compounds for which this part of ISO 16017 has been tested are
given in tables. This part of ISO 16017 may be applicable to compounds not listed, but in these cases it is
advisable to use a back-up tube containing the same or a stronger sorbent.
This part of ISO 16017 is applicable to the measurement of airborne vapours of VOCs in a concentration range of
3 3
approximately 0,5�g/ m to 100 mg/m individual compound.
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 sorptive capacity is measured as a breakthrough volume of air, which determines the
maximum air volume that shall not be exceeded when sampling.
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 and molecular
sieves such as Spherocarb, or pure charcoal; at low nanogram levels for Tenax TA and at 5 ng to 50 ng levels for
�
other porous polymers such as Chromosorbs and Porapaks. Sensitivity is typically limited to 0,5 �g/m for 10-litre
air samples with this latter group of sorbents because of their inherent high background.
The procedure specified in this part of ISO 16017 is applicable to low flowrate personal sampling pumps and gives
a time-weighted average result. It is not applicable to the measurement of instantaneous or short-term fluctuations
in concentration.
1) The sorbents listed in annex C and elsewhere in this International Standard 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.
ISO 16017-1:2000(E)
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of
this part of ISO 16017. For dated references, subsequent amendments to, or revisions of, any of these publications
do not apply. However, parties to agreements based on this part of ISO 16017 are encouraged to investigate the
possibility of applying the most recent editions of the normative documents indicated below. For undated
references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain
registers of currently valid International Standards.
ISO 5725-1:1994, Accuracy (trueness and precision) of measurement methods and results — Part 1: General
principles and definitions.
ISO 5725-2:1994, Accuracy (trueness and precision) of measurement methods and results — Part 2: Basic method
for the determination of repeatability and reproducibility of a standard measurement method.
ISO 6141:2000, Gas analysis — Requirements for certificates for calibration gases and gas mixtures.
ISO 6145-1:1986, Gas analysis — Preparation of calibration gas mixtures using dynamic volumetric methods —
Part 1: Methods of calibration.
ISO 6145-3:1986, Gas analysis — Preparation of calibration gas mixtures — Dynamic volumetric methods —
Part 3: Periodic injections into a flowing gas stream.
ISO 6145-4:1986, Gas analysis — Preparation of calibration gas mixtures — Dynamic volumetric methods —
Part 4: Continuous injection method.
2)
ISO 6145-5:— , Gas analysis — Preparation of calibration gas mixtures using dynamic volumetric methods —
Part 5: Capillary calibration devices.
2)
ISO 6145-6:— , Gas analysis — Preparation of calibration gas mixtures using dynamic volumetric methods —
Part 6: Critical orifices.
ISO 6349:1979, Gas analysis — Preparation of calibration gas mixtures — Permeation method.
EN 1076:1997, Workplace atmospheres — Pumped sorbent tubes for the determination of gases and vapours —
Requirements and test methods.
3 Terms and definitions
For the purposes of this part of ISO 16017, the following terms and definitions apply.
3.1
breakthrough volume
volume of test atmosphere that can be passed through a sorbent tube before the concentration of eluting vapour
reaches 5 % of the applied test concentration
NOTE 1 The breakthrough volume varies with the vapour and the sorbent type.
NOTE 2 See reference [4]. 3.2
retention volume
elution volume at peak maximum of a small aliquot of an organic vapour eluted from a sorbent tube by air or
chromatographic carrier gas
2) To be published.
2 © ISO 2000 – All rights reserved

ISO 16017-1:2000(E)
4Principle
A measured volume of sample air is drawn through one (or more) sorbent tubes in series; an appropriate sorbent
(or sorbents) being selected for the compound or mixture to be sampled. Provided suitable sorbents are chosen,
volatile organic components are retained by the sorbent tube and thus are removed from the flowing air stream.
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. Analytical calibration is achieved by means of liquid or vapour spiking onto a sorbent tube.
5 Reagents and materials
During the analysis, use only reagents of recognized analytical reagent grade.
Fresh standard calibration blend solutions should be prepared weekly, or more frequently if evidence is noted of
deterioration, e.g. condensation reactions between alcohols and ketones.
5.1 Volatile organic compounds, for calibration purposes, using either liquid spiking (5.7 and 5.8) or vapour
spiking (5.4 to 5.6) onto sorbent tubes.
5.2 Dilution solvent, for preparing calibration blend solution for liquid spiking (5.7). This should be of
chromatographic quality. It shall be free from compounds co-eluting with the compound or compounds of interest
(5.1).
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.
5.3 Sorbents, of recommended particle size 0,18 mm to 0,25 mm (60 to 80 mesh).
Each sorbent should be preconditioned under a flow of inert gas by heating it overnight (= 16 h) at a temperature at
least 25�C below the published maximum for that sorbent before packing the tubes. To prevent recontamination of
the sorbents, 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.
NOTE 1 Sorbent particle sizes larger than 0,18 mm to 0,25 mm may be used but the breakthrough characteristics given in
Tables 1 to 6 may be affected. Smaller sorbent particle size ranges are not recommended because of back-pressure problems.
NOTE 2 A description of sorbents is given in annex C and a guide for sorbent selection is given in annex D. Equivalent
sorbents may be used. A guide to sorbent conditioning and analytical desorption parameters is given in annex E.
5.4 Calibration standards, preferably prepared by loading required amounts of the compounds of interest on
sorbent tubes from standard atmospheres (see 5.5 and 5.6), 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 5.7 and
5.8), provided that the accuracy of the spiking technique is either:
a) established by using procedures giving spiking levels fully traceable to primary standards of mass and/or
volume, or,
b) confirmed by comparison with reference materials, if available, standards produced using standard
atmospheres, or results of reference measurement procedures.
NOTE The loading ranges given in 5.6, 5.7 and 5.8 are not mandatory and approximate to the application range given in
clause 1 for a 2-litre sample. For specific applications in which larger volumes are used to measure lower concentrations, other
loading ranges may be more appropriate.
ISO 16017-1:2000(E)
5.5 Standard atmospheres.
Prepare standard atmospheres of known concentrations of the compound(s) of interest by a recognized procedure.
Methods described in ISO 6141, the appropriate part of ISO 6145 and ISO 6349 are suitable. 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.
5.6 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
3 3
with each batch of samples. Prepare standard atmospheres equivalent to 10 mg/m and 100�g/m . For workplace
air, load sorbent tubes with 100 ml, 200 ml, 400 ml, 1 l, 2 l, or 4 l of the 10 mg/m atmosphere. For ambient or
indoor air, load sorbent tubes with 100 ml, 200 ml, 400 ml, 1 l, 2 l, 4 l or 10 l of the 100�g/m atmosphere.
5.7 Solutions for liquid spiking.
5.7.1 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 (5.2), stopper and shake to mix.
5.7.2 Solution 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 5.7.1 Make up to 100 ml with
dilution solvent, stopper and shake to mix.
5.7.3 Solution containing approximately 100 ����g/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 (5.2), stopper and shake to mix.
5.7.4 Solution containing approximately 10 ��g/ml of liquid components.
��
Introduce 50 ml of dilution solvent into a 100 ml volumetric flask. Add 10 ml of solution described in 5.7.3. Make up
to 100 ml with dilution solvent, stopper and shake to mix.
5.7.5 Solution containing approximately 1 mg/ml of gas components.
For gases, e.g. ethylene oxide, a high level calibration solution may 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, but correct for any non-ideality of the particular pure gas compound.
4 © ISO 2000 – All rights reserved

ISO 16017-1:2000(E)
5.7.6 Solution containing approximately 10µg/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 10µl
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, but correct for any non-ideality of the
particular pure gas compound.
5.8 Standard sorbent tubes loaded by liquid spiking.
Prepare loaded sorbent tubes by injecting aliquots of standard solutions onto clean sorbent tubes as follows. Fit a
sorbent tube into the injection unit (6.10) through which inert purge gas and a 1µl to 4µl aliquot of an appropriate
standard solution, injected through the septum, are passed. After an appropriate time, disconnect and seal the
tube. Prepare fresh standards with each batch of samples. For workplace air, load sorbent tubes with 1µl to 5µl of
solutions 5.7.1, 5.7.2 or 5.7.5. For ambient and indoor air, load sorbent tubes with 1µl to 5µl of solutions 5.7.3,
5.7.4 or 5.7.6.
NOTE In the case of methanol, a purge gas flowrate of 100 ml/min and a 5 min purge time have been found to be
appropriate to eliminate most of the solution solvent from the tube. If other dilution solvents are used, the conditions should be
determined experimentally.
6 Apparatus
Use ordinary laboratory apparatus and the following.
6.1 Sorbent tubes, compatible with the thermal desorption apparatus to be used (6.9).
Typically, but not exclusively, sorbent tubes are constructed of stainless steel tubing, 6,3 mm (1/4 inch) OD, 5 mm
ID and 90 mm long. Tubes of other dimensions may be used but the safe sampling volumes (SSV) given in
Tables 1 to 6 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. One end of the tube is marked, for example by a
scored ring about 10 mm from the sampling inlet end. The tubes are packed with one or more preconditioned
sorbents (5.3) so that the sorbent bed will be within the desorber heated zone and a gap of at least 14 mm is
retained at each end to minimize errors due to diffusive ingress at very low pump flowrates. Tubes contain between
200 mg and 1 000 mg sorbent, depending on sorbent density (typically about 250 mg porous polymer or 500 mg
carbon molecular sieve or graphitized carbon). The sorbents are retained by stainless steel gauzes and/or
unsilanized glass wool plugs. If more than one sorbent is used in a single tube, the sorbents should be arranged in
order of increasing sorbent strength and separated by unsilanized glass wool, with the weakest sorbent nearest to
the marked sampling inlet end of the tube.
Do not pack sorbents with widely different (� 50�C) maximum desorption temperatures into a single tube, or it will
be impossible to condition or desorb the more stable sorbent(s) sufficiently thoroughly without causing degradation
of the least stable sorbent(s).
6.2 Sorbent tube end caps.
The tubes shall be sealed according to the requirements of EN 1076:1997, subclause 5.6, or equivalent, e.g. with
metal screw-cap fittings with polytetrafluoroethylene (PTFE) seals.
6.3 Sorbent tube unions.
Two sorbent tubes may be connected in series during sampling with metal screw-cap couplings with PTFE seals.
ISO 16017-1:2000(E)
6.4 Syringes, including a precision 10µl liquid syringe readable to 0,1µl, a precision 10 �l gas-tight syringe
readable to 0,1µl and a precision 1 ml gas-tight syringe readable to 0,01 ml.
6.5 Sampling pump
The pump should fulfil the requirements of EN 1232 [10] or equivalent.
The sampling pump shall be in accordance with local safety regulations.
6.6 Plastic or rubber tubing, about 90 cm long, of appropriate diameter to ensure a leak-proof fit to both pump
and sample tube or tube holder, if used. Clips should be provided to hold the sample tube and connecting tubing.
Sampling tubes shall not be used with plastic or rubber tubing upstream of the sorbent. The use of such tubing may
introduce contaminants or sorbed sampled VOCs.
6.7 Soap-bubble meter or other suitable device for calibrating pump.
The flow meter shall be traceably calibrated to a primary flow standard.
NOTE The use of an uncalibrated integral flow meter for the calibration of pump flowrates may result in systematic errors of
several tens of percent.
6.8 Gas chromatograph, fitted with a flame ionization, 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.
The gas chromatograph shall have a capillary column capable of separating the analytes of interest from other
components.
6.9 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
flowrate. 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 (10.2). The desorbed sample,
contained in the purge gas, is routed to the gas chromatograph and capillary column via a heated transfer line.
6.10 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.
7 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 E). Typical conditioning time is 10 min with carrier gas flowrate of 100 ml/min.
The carrier gas flow should be in a direction opposite to that used during sampling. Tubes should then be analysed,
using routine analytical parameters, to ensure that the thermal desorption blank is sufficiently small. If the blank is
unacceptable, tubes should be reconditioned by repeating this procedure. Once a sample has been analysed, the
tube may be reused to collect a further sample immediately. However, it is advisable to check the thermal
desorption blank if the tubes are left for an extended period before reuse, or if sampling for a different analyte is
envisaged. Tubes should be sealed with metal screwcaps with combined PTFE ferrule fittings and stored in an
airtight container when not used for sampling or being conditioned.
NOTE The sorbent tube blank level is acceptable if interfering peaks are no greater than 10% of the typical areas of the
analytes of interest.
6 © ISO 2000 – All rights reserved

ISO 16017-1:2000(E)
8 Calibration of pump
Calibrate the pump with a representative sorbent tube assembly in-line, using an appropriate external calibrated
meter.
One end of the calibrated flow meter should be at atmospheric pressure to ensure proper operation.
9 Sampling
Select a sorbent tube (or tube combination) appropriate for the compound or mixture to be sampled. Guidance on
suitable sorbents is given in annex D.
If more than one tube is to be used, prepare a tube assembly by joining the tubes with a union (6.3).
Attach the pump to the sorbent tube or tube assembly with plastic or rubber tubing, so that the tube containing the
stronger sorbent is nearest the pump.
When used for personal sampling, to minimize channelling the tube assembly should be mounted vertically in the
breathing zone. The pump is attached as appropriate to minimize inconvenience. When used for fixed location
sampling, a suitable sampling site is chosen.
Turn the pump on and adjust the flowrate so that the recommended sample volume is taken in the available time.
The recommended air sample volume for the volatile organic compounds covered by this standard is between 1
litre and 10 litres. If the total sample is likely to exceed 1 mg (i.e. 1 mg on each tube), the sample volume shall be
reduced accordingly, or overload may occur.
NOTE 1 Sampling efficiency is 100 % (quantitative), provided the sampling capacity of the sorbents is not exceeded. If this
capacity is exceeded, breakthrough of vapour from the tube assembly will occur. The breakthrough volume may be measured
by sampling from a standard vapour atmosphere, whilst monitoring the effluent air with a flame ionization or equivalent detector
(a suitable method is described in annex A). Alternatively, instead of determining the breakthrough volume directly, the
mathematically related retention volume may be determined. The retention volume is determined chromatographically at
elevated temperatures and subsequent extrapolation to room temperature. A suitable method is described in annex B.
The breakthrough volume of porous polymers vary with ambient air temperature, reducing by a factor of about 2 for
each 10�C rise in temperature. It also varies with sampling flowrate, being reduced substantially at flowrates below
5 ml/min or above 500 ml/min. The breakthrough volumes of carbon molecular sieves are less affected by
temperature and flowrate, but are substantially reduced at high concentrations of volatile organic vapour or high
relative humidity. To allow a suitable margin of safety, a safe sampling volume (SSV) is defined such that it is a
volume of not more than 70 % of the 5 %-breakthrough volume (see A.1.1 in annex A) or 50 % of the retention
volume (see B.1 in annex B). Tables 1 to 6 give typical values for retention volumes and safe sampling volumes.
These values have been determined by the chromatographic method (annex B).
NOTE 2 The safe sampling volumes in Tables 1 to 6 have been determined by the chromatographic method (annex B).
Measurements by the direct method (annex A) [4] indicate that the chromatographic method is a reliable indication of the true
breakthrough capacity except under conditions of high concentrations or very high humidity. These measurements [4] indicate
that breakthrough volumes at high (80 %) humidity are about a factor of two lower for porous polymers and a factor of ten lower
for carbonaceous sorbents than the low humidity value. If high concentrations [� 300 mg/m (100 ppm)] are also anticipated, the
breakthrough volumes for carbonaceous sorbents should be further reduced by a factor of two.
If safe sampling volumes for compounds are estimated which are not listed in Table 1, this estimation is only
possible for such compounds which are situated between the two listed compounds of homologues of a chemical
group. In all other cases the safe sampling volume shall be tested experimentally with appropriate trials (e.g. similar
sampling media in-line and separate analysis).
Note and record the times, temperature, flowrate or register reading if appropriate and the barometric pressure
when the pump was turned on. At the end of the sampling period, note and record the flowrate or register reading,
turn the pump off, and note and record the time, temperature and barometric pressure.
ISO 16017-1:2000(E)
Disconnect the sample tube assembly and seal both ends of each tube with compression seals. Tighten these
seals securely. The tubes should be uniquely labelled. Solvent-containing paints and markers or adhesive labels
should not be used to label the tubes.
If samples are not to be analysed within 8 h, place them in a clean, uncoated, refrigerated sealed metal or glass
container. If possible the sampler should be refrigerated during transportation.
Record air temperature and barometric pressure periodically during sampling if it is desired to express
concentrations reduced to specific conditions (11.1).
Field blanks should be prepared by using tubes identical to those used for sampling and subjecting them to the
same handling procedure as the sample tubes except for the actual period of sampling. Label these as blanks.
NOTE 3 Since this method uses thermal desorption, unless the TD apparatus has the facility to retrap the sample after
analysis, there will generally only be one opportunity to analyse the sample. If the sample is important and the chance of
overload and/or sample breakthrough is a possibility, a second sample at a lower flowrate should be taken.
10 Procedure
10.1 Safety precautions
This part of ISO 16017 does not purport to address all of the safety concerns, if any, associated with its use. It is
the responsibility of the user of this part of ISO 16017 to establish appropriate health and safety practices and
determine the applicability of regulatory limitations prior to use.
10.2 Desorption and analysis
Place the sorbent tube in a compatible thermal desorption apparatus. Purge the air from the tube to avoid
chromatographic artefacts arising from the thermal oxidation of the sorbent or gas chromatographic stationary
phase. Then heat the tube to displace the organic vapours which are passed to the gas chromatograph by means
of a carrier gas stream. The gas flow direction at this stage should be the reverse of that used during sampling, i.e.
the marked end of the tube should be nearest the gas chromatograph column inlet. Typically the gas flowrate
through the tube should be in the order of 30 ml/min to 50 ml/min for optimum desorption efficiency.
For the initial air purge, it is usually necessary to use 10� the tube volume (i.e. 20 ml to 30 ml) of inert gas to
completely displace the volume of air (2 ml to 3 ml) in the tube. However, if strongly hydrophilic sorbents are
needed, it may be necessary to employ a larger purge to reduce sorbed air and water to prevent ice formation
blocking the cold trap. During the purge period, care should be taken to minimize heating of the tube.
The desorbed sample occupies a volume of several millilitres of gas, so that pre-concentration is essential prior to
capillary GC analysis. This can be achieved using a small, cooled, secondary sorbent trap, which can be desorbed
sufficiently rapidly at low flowrates (� 5 ml/min) to minimize band-broadening and produce capillary-compatible
peaks. Alternatively, an empty secondary trap, or one containing an inert material such as glass beads, can be
used to pre-concentrate the sample, but such traps typically require cooling to below –100�C. Alternatively, the
desorbed sample can be passed directly to the gas chromatograph (single-stage desorption), where it shall be
refocused. This typically requires a high phase-ratio column (e.g. 5µm film thickness, 0,2 mm to 0,32 mm ID) and a
sub-ambient starting temperature.
If a secondary sorbent cold trap is not available and if sub-zero capillary cryofocusing temperatures are used to
preconcentrate the analytes, water shall be completely eliminated from the sample tube prior to desorption in order
to prevent ice formation blocking the capillary tubing and stopping the thermal desorption process.
NOTE 1 If a secondary cold trap is not available and optimum sample tube desorption flowrates of 30 ml/min to 50 ml/min are
used, a minimum split ratio of 30:1 to 50:1 will typically be required for operation with high-resolution capillary columns. Single-
stage thermal desorption may thus limit sensitivity.
Desorption conditions should be chosen such that desorption from the sample tube is complete, and no sample
loss occurs in the secondary trap, if used. Typical parameters are:
8 © ISO 2000 – All rights reserved

ISO 16017-1:2000(E)
Desorption temperature
250�C to 325�C
Desorption time 5 min to 15 min
Desorption flowrate 30 ml/min to 50 ml/min
Cold trap low +20�Cto –180�C, depending on type of cold trap
Cold trap high
250�C to 350�C
Cold trap sorbent typically same as tubes, 40 mg to 100 mg, if used
Carrier gas helium
Split ratios Split ratios between the sample tube and secondary trap and
between the secondary trap and analytical column (if applicable)
should be selected dependent on expected atmospheric
concentration. (See guidance from respective manufacturers of
the thermal desorption apparatus.)
The desorption temperature depends on the analyte and the sorbent used. Recommendations are given in
Tables 1 to 6, but the maximum desorption temperatures given in annexes D and E for particular sorbents should
be respected. Due to their potential thermal instability, secondary and tertiary volatile amines and some
polyhalogenated compounds having one or two carbon atoms, especially brominated compounds, may suffer some
thermal degredation.
Set the sample flow path temperature (transfer line temperature) high enough to prevent analyte condensation but
not so high as to cause degradation. Analytes sufficiently volatile to be present in the vapour phase in air at
ambient temperature, do not usually require flow path temperatures above 150�C, however some types of
apparatus may require higher temperatures.
Set up the gas chromatograph for the analysis of volatile organic compounds. A variety of chromatographic
columns may be used for the analysis of these compounds. The choice will depend largely on which compounds, if
any, are present that might interfere in the chromatographic analysis.
NOTE 2 Typical examples, as used to determine the data in Table 8, are 50 m � 0,22 mm fused silica columns with thick-film
(1µm to 5µm) dimethylsiloxane or a 50 m stationary phase of 7 % cyanopropyl, 7 % phenyl, 86 % methylsiloxane. Typical
operating conditions for these columns are a temperature programme from 50 �Cto 250 �Cat5�C /min, with an initial hold time
of 10 min at 50�C.
The capillary column or, preferably, a length of uncoated, deactivated fused silica, should be threaded back
through the transfer line from the thermal desorption apparatus to the gas chromatograph such that it reaches as
close as possible to the sorbent in the cold trap or as near as possible to the tube in a single-stage desorber.
Internal tubing shall be inert and dead volumes shall be minimized. A split valve(s) is conveniently placed at the
inlet and/or outlet of the secondary trap. The split valve on the outlet of the secondary trap may be located either at
the inlet or the outlet of the transfer line. Split ratios depend on the application.
NOTE 3 Lower split ratios are suitable for ambient (typically 1:1 to 10:1) and indoor and some workplace air measurements
(typically 1:1 to 20:1); higher split ratios for most workplace air measurements (typically 100:1 to 1000:1).
Correspondence of retention time on a single column should not be regarded as proof of identity.
10.3 Calibration
Analyse each sorbent tube standard (5.6 or 5.8) by thermal desorption and gas chromatography.
Prepare a calibration graph by plotting the base-ten logarithm of the areas of the analyte peaks, corrected for blank
levels, on the vertical scale against the base-ten logarithm of the mass of the analyte, in micrograms, on the
sorbent tube standard corresponding to the solutions 5.7 or atmospheres 5.4.
ISO 16017-1:2000(E)
NOTE If the calibration range is less than one order of magnitude, then it is not necessary to take logarithms of the data.
10.4 Determination of sample concentration
Analyse the samples and sample blanks as described for the calibration standards in 10.2. Determine the peak
area and read from the calibration graph the mass of the analyte in the desorbed sample.
10.5 Determination of desorption efficiency
The efficiency of desorption should be checked by comparing the chromatographic response of a sorbent tube
standard (10.3) with that obtained by injecting aliquots of the standard solutions or the atmosphere directly into the
gas chromatograph. Thus prepare a second calibration graph of peak area against mass of analyte as in 10.3, but
using solutions 5.7 or atmosphere 5.6. This calibration should be the same or nearly the same as that in 10.3. The
desorption efficiency is the response of a tube standard divided by that of the corresponding liquid standard
injected directly. If the desorption efficiency is less than 95 %, change the desorption parameters accordingly.
NOTE Some makes of thermal desorber do not have a direct liquid injection
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