SIST EN ISO 27108:2013
(Main)Water quality - Determination of selected plant treatment agents and biocide products - Method using solid-phase microextraction (SPME) followed by gas chromatography-mass spectrometry (GC-MS) (ISO 27108:2010)
Water quality - Determination of selected plant treatment agents and biocide products - Method using solid-phase microextraction (SPME) followed by gas chromatography-mass spectrometry (GC-MS) (ISO 27108:2010)
This International Standard specifies a method for the determination of the dissolved amount of selected plant treatment agents and biocide products in drinking water, ground water and surface water by solid-phase microextraction (SPME) followed by gas chromatography-mass spectrometry (GC-MS). The limit of determination depends on the matrix, on the specific compound to be analysed and on the sensitivity of the mass spectrometer. For most plant treatment agents and biocides to which this International Standard applies, it is at least 0,05 μg/l. Validation data related to a concentration range between 0,05 μg/l and 0,3 μg/l have been demonstrated in an interlaboratory trial. This method may be applicable to other compounds not explicitly covered by this International Standard or to other types of water. However, it is necessary to verify the applicability of this method for these special cases. NOTE Determinations by this International Standard are performed on small sample amounts (e.g. sample volumes between 8 ml and 16 ml).
Wasserbeschaffenheit - Bestimmung ausgewählter Pflanzenbehandlungsmittel, Biozide und Abbauprodukte - Verfahren mittels Gaschromatographie (GC-MS) nach Festphasenmikroextraktion (SPME) (ISO 27108:2010)
Diese Internationale Norm legt ein Verfahren für die Bestimmung ausgewählter Pflanzenschutzmittel und Biozidprodukte, gelöst in Trink , Grund und Oberflächenwasser fest, mittels Festphasenmikroextraktion (SPME) und einem gaschromatographischen Verfahren mit massenspektrometrischer Detektion (GC-MS). Die Bestimmungsgrenze des Verfahrens ist abhängig von der Probenmatrix, der jeweils zu untersuchenden Verbindung und der Empfindlichkeit des Massenspektrometers. Für die meisten Pflanzenschutzmittel und Biozidprodukte, auf die sich diese Internationale Norm bezieht (siehe Tabelle 1), liegt sie mindestens bei 0,05 µg/l. In einem Ringversuch wurden Daten zur Methodenvalidierung in einem Konzentrationsbereich von 0,05 µg/l bis 0,3 µg/l erhoben.
Die Anwendbarkeit des Verfahrens auf weitere, in dieser Internationalen Norm nicht ausdrücklich genannten Verbindungen oder andere Wässer ist nicht ausgeschlossen; sie muss jedoch im Einzelfall geprüft werden.
ANMERKUNG Die Bestimmungen nach dieser Internationalen Norm werden mit kleinen Probenvolumina (z. B. zwischen 8 ml und 16 ml) durchgeführt.
Qualité de l'eau - Détermination d'agents de traitement et de produits d'usine sélectionnés - Méthode utilisant une micro-extraction en phase solide (MEPS) suivie d'une chromatographie en phase gazeuse-spectrométrie de masse (CG-SM) (ISO 27108:2010)
L'ISO 27108:2010 spécifie une méthode pour la détermination de la quantité d'agents de traitement et de produits d'usine sélectionnés dissous dans l'eau potable, les eaux souterraines et les eaux de surface par micro-extraction en phase solide (MEPS) suivie d'une chromatographie en phase gazeuse-spectrométrie de masse (CG-SM). La limite de la détermination dépend de la matrice, du composé spécifique à analyser et de la sensibilité du spectromètre de masse. Pour la plupart des agents de traitement et de produits d'usine auxquels l'ISO 27108:2010 s'applique, elle est d'au moins 0,05 µg/l. Les données de validation relatives à une gamme de concentrations comprises entre 0,05 µg/l et 0,3 µg/l ont été démontrées lors d'un essai interlaboratoires.
Cette méthode peut être applicable à d'autres composés qui ne sont pas explicitement traités dans l'ISO 27108:2010 ou à d'autres types d'eau. Toutefois, il est nécessaire de vérifier l'applicabilité de cette méthode à ces cas particuliers.
Kakovost vode - Določevanje izbranih sredstev za zaščito rastlin in biocidov - Metoda s plinsko kromatografijo/masno spektrometrijo (GC/MS) po mikroekstrakciji na trdni fazi (SPME) (ISO 27108:2010)
Ta mednarodni standard določa metodo za določanje raztopljene količine izbranih sredstev za zaščito rastlin in biocidov v pitni vodi, podtalnici in površinski vodi s plinsko kromatografijo/masno spektrometrijo (GC/MS) po mikroekstrakciji na trdni fazi (SPME). Meja določevanja je odvisna od matrice, specifične spojine za analizo in občutljivosti masnega spektometra. Pri večini sredstev za zaščito rastlin in biocidov, za katere velja ta mednarodni standard, znaša ta meja vsaj 0,05 μg/l. Podatki o validaciji, ki se nanašajo na razpon koncentracije med 0,05 μg/l in 0,3 μg/l, so bili prikazani z mednarodnim medlaboratorijskim poskusom. Ta metoda lahko velja za druge spojine, ki niso izrecno zajete v tem mednarodnem standardu, ali za druge vrste vode. Vendar je treba za te posebne primere uporabnost te metode preveriti. OPOMBA: Določbe iz tega mednarodnega standarda izhajajo iz majhnih vzorčnih količin (tj. vzorčni volumen med 8 in 16 ml).
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 27108:2013
01-september-2013
.DNRYRVWYRGH'RORþHYDQMHL]EUDQLKVUHGVWHY]D]DãþLWRUDVWOLQLQELRFLGRY
0HWRGDVSOLQVNRNURPDWRJUDILMRPDVQRVSHNWURPHWULMR *&06 SR
PLNURHNVWUDNFLMLQDWUGQLID]L 630( ,62
Water quality - Determination of selected plant treatment agents and biocide products -
Method using solid-phase microextraction (SPME) followed by gas chromatography-
mass spectrometry (GC-MS) (ISO 27108:2010)
Wasserbeschaffenheit - Bestimmung ausgewählter Pflanzenbehandlungsmittel, Biozide
und Abbauprodukte - Verfahren mittels Gaschromatographie (GC-MS) nach
Festphasenmikroextraktion (SPME) (ISO 27108:2010)
Qualité de l'eau - Détermination d'agents de traitement et de produits d'usine
sélectionnés - Méthode utilisant une micro-extraction en phase solide (MEPS) suivie
d'une chromatographie en phase gazeuse-spectrométrie de masse (CG-SM) (ISO
27108:2010)
Ta slovenski standard je istoveten z: EN ISO 27108:2013
ICS:
13.060.50 3UHLVNDYDYRGHQDNHPLþQH Examination of water for
VQRYL chemical substances
SIST EN ISO 27108:2013 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN ISO 27108:2013
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SIST EN ISO 27108:2013
EUROPEAN STANDARD
EN ISO 27108
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2013
ICS 13.060.50
English Version
Water quality - Determination of selected plant treatment agents
and biocide products - Method using solid-phase microextraction
(SPME) followed by gas chromatography-mass spectrometry
(GC-MS) (ISO 27108:2010)
Qualité de l'eau - Détermination d'agents de traitement et Wasserbeschaffenheit - Bestimmung ausgewählter
de produits d'usine sélectionnés - Méthode utilisant une Pflanzenschutzmittel und Biozidprodukte - Verfahren
micro-extraction en phase solide (MEPS) suivie d'une mittels Festphasenmikroextraktion (SPME) gefolgt von der
chromatographie en phase gazeuse-spectrométrie de Gaschromatographie und Massenspektrometrie (GC-MS)
masse (CG-SM) (ISO 27108:2010) (ISO 27108:2010)
This European Standard was approved by CEN on 12 April 2013.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same
status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2013 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 27108:2013: E
worldwide for CEN national Members.
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SIST EN ISO 27108:2013
EN ISO 27108:2013 (E)
Contents Page
Foreword .3
2
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SIST EN ISO 27108:2013
EN ISO 27108:2013 (E)
Foreword
The text of ISO 27108:2010 has been prepared by Technical Committee ISO/TC 147 “Water quality” of the
International Organization for Standardization (ISO) and has been taken over as EN ISO 27108:2013 by
Technical Committee CEN/TC 230 “Water analysis” the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by February 2014, and conflicting national standards shall be withdrawn
at the latest by February 2014.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech
Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
Endorsement notice
The text of ISO 27108:2010 has been approved by CEN as EN ISO 27108:2013 without any modification.
3
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SIST EN ISO 27108:2013
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SIST EN ISO 27108:2013
INTERNATIONAL ISO
STANDARD 27108
First edition
2010-04-15
Water quality — Determination of
selected plant treatment agents and
biocide products — Method using solid-
phase microextraction (SPME) followed
by gas chromatography-mass
spectrometry (GC-MS)
Qualité de l'eau — Détermination d'agents de traitement et de produits
d'usine sélectionnés — Méthode utilisant une micro-extraction en phase
solide (MEPS) suivie d'une chromatographie en phase gazeuse-
spectrométrie de masse (CG-SM)
Reference number
ISO 27108:2010(E)
©
ISO 2010
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SIST EN ISO 27108:2013
ISO 27108:2010(E)
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ii © ISO 2010 – All rights reserved
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SIST EN ISO 27108:2013
ISO 27108:2010(E)
Contents Page
Foreword .iv
Introduction.v
1 Scope.1
2 Normative references.1
3 Principle.1
4 Interferences .2
5 Reagents.4
6 Apparatus.5
7 Sampling and sample pretreatment .6
8 Procedure.6
9 Calibration.8
10 Calculation .11
11 Expression of results.11
12 Test report.11
Annex A (informative) Examples of gas chromatograms for compounds listed in Table 1 .12
Annex B (informative) Mass spectra of compounds of Table 1 (full-scan, EI, 70 eV).21
Annex C (informative) Precision data .35
Annex D (informative) General information about SPME .36
Bibliography.37
© ISO 2010 – All rights reserved iii
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SIST EN ISO 27108:2013
ISO 27108:2010(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 27108 was prepared by Technical Committee ISO/TC 147, Water quality, Subcommittee SC 2, Physical,
chemical and biochemical methods.
iv © ISO 2010 – All rights reserved
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SIST EN ISO 27108:2013
ISO 27108:2010(E)
Introduction
In recent years, ground water contamination as well as surface water contamination by pesticides has become
a matter of public concern. Identification and quantification of pesticides at trace level concentrations often
require both high sensitive chromatographic equipment and effective enrichment steps. In the analysis of
aqueous samples, sample preparation techniques including solid-phase extraction (SPE) are frequently the
most time-consuming steps and in many cases can be effectively replaced by solid-phase microextraction
(SPME).
When using this International Standard, it may be necessary in some cases to determine whether and to what
extent particular problems could require the specification of additional marginal conditions.
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SIST EN ISO 27108:2013
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SIST EN ISO 27108:2013
INTERNATIONAL STANDARD ISO 27108:2010(E)
Water quality — Determination of selected plant treatment
agents and biocide products — Method using solid-phase
microextraction (SPME) followed by gas chromatography-mass
spectrometry (GC-MS)
WARNING — Persons using this International Standard should be familiar with normal laboratory
practice. This International Standard does not purport to address all of the safety problems, if any,
associated with its use. It is the responsibility of the user to establish appropriate safety and health
practices and to ensure compliance with any national regulatory conditions.
IMPORTANT — It is absolutely essential that tests conducted according to this International Standard
be carried out by suitably trained staff.
1 Scope
This International Standard specifies a method for the determination of the dissolved amount of selected plant
treatment agents and biocide products in drinking water, ground water and surface water by solid-phase
microextraction (SPME) followed by gas chromatography-mass spectrometry (GC-MS). The limit of
determination depends on the matrix, on the specific compound to be analysed and on the sensitivity of the
mass spectrometer. For most plant treatment agents and biocides to which this International Standard applies,
it is at least 0,05 µg/l. Validation data related to a concentration range between 0,05 µg/l and 0,3 µg/l have
been demonstrated in an interlaboratory trial.
This method may be applicable to other compounds not explicitly covered by this International Standard or to
other types of water. However, it is necessary to verify the applicability of this method for these special cases.
NOTE Determinations by this International Standard are performed on small sample amounts (e.g. sample volumes
between 8 ml and 16 ml).
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 3696, Water for analytical laboratory use — Specification and test methods
ISO 5667-1, Water quality — Sampling — Part 1: Guidance on the design of sampling programmes and
sampling techniques
ISO 5667-3, Water quality — Sampling — Part 3: Guidance on the preservation and handling of water
samples
3 Principle
Substances under investigation are extracted from the water sample by solid-phase microextraction (SPME)
according to their equilibrium of distribution. The extraction is performed by a chemically modified fused-silica
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SIST EN ISO 27108:2013
ISO 27108:2010(E)
fibre, the surface of which is coated with a suitable adsorbent polymer. During extraction, the fibre is
immersed in the liquid sample. After completion of the extraction procedure, the fibre is drawn back into the
needle, removed from the sample vial, and introduced directly into the GC injector. The analytes are
transferred to the GC column by thermal desorption.
The analytes are separated, identified and quantified by means of capillary gas chromatography with mass
spectrometric detection (GC-MS) using electron impact (EI) ionisation mode.
Table 1 — Plant treatment agents and biocide products determined by this method
Reference No. in example
Molar mass
chromatograms of Figure
Name Molecular formula CAS registry No.
g/mol A.1 A.2 A.3
Dichlobenil C H ClN 1194-65-6 172,0 1 1 1
7 3 2
Desethylatrazine C H ClN 6190-65-4 187,6 2 2 3
6 10 5
Desethylterbutylazine C H ClN 30125-63-4 201,7 3 3 2
7 12 5
Simazine C H ClN 122-34-9 201,7 4 4 7
7 12 5
Atrazine C H ClN 1912-24-9 215,7 6 5 5
8 14 5
Lindane C H Cl 58-89-9 290,8 7 6 8
6 6 6
Terbutylazine C H ClN 5915-41-3 229,7 8 7 6
9 16 5
Metribuzine C H NOS 21087-64-9 214,3 9 8 14
8 14 4
Parathion-methyl C H NOPS 298-00-0 263,2 10 9 11
8 10 5
Heptachlor C H Cl 76-44-8 373,3 11 10 9
10 5 7
Terbutryn C H NS 886-50-0 241,4 12 11 12
10 19 5
Aldrin C H Cl 309-00-2 364,9 13 12 10
12 8 6
Metolachlor C H ClNO 51218-45-2 283,8 14 13 13
15 22 2
Parathion-ethyl C H NOPS 56-38-2 291,3 15 14 15
10 14 5
exo-Heptachlorepoxide C H ClO 1024-57-3 389,3 16 16 16
10 5 7
Pendimethalin C H N O 40487-42-1 281,3 17 15 17
13 19 3 4
endo-Heptachlorepoxide C H ClO 28044-83-9 389,3 18 17 18
10 5 7
Triclosan C H Cl O 3380-34-5 289,5 19 18 19
12 7 3 2
Dieldrin C H ClO 60-57-1 380,9 20 19 20
12 8 6
Carfentrazone-ethyl C H Cl F N O 128639-02-1 412,2 21 20 21
15 14 2 3 3 3
Diflufenican C H F N O 83164-33-4 394,3 22 21 22
19 11 5 2 2
Mefenpyr-diethyl C H Cl N O 135590-91-9 373,2 23 22 23
16 18 2 2 4
4 Interferences
4.1 Interferences during sampling
To avoid interference, collect samples as specified in Clause 7, observing the instructions specified in
ISO 5667-1 and ISO 5667-3.
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SIST EN ISO 27108:2013
ISO 27108:2010(E)
4.2 Interferences during extraction procedure
Commercially available SPME fibres differ frequently in quality. Variations in the selectivity of the materials
also frequently occur from batch to batch, thus possibly causing significant deviations in extraction yield. This
does not basically impair their suitability, apart from a resulting higher detection limit of individual substances.
Inadequately conditioned fibres frequently result in lower extraction yields and poorly reproducible results;
therefore precondition new fibres according to Clause 8. Also condition used fibres by performing the whole
SPME process using at least two sampling vials containing only water (5.1) prior to starting with the first
sample of a new sample sequence.
Sensitivity of fibres gradually decreases throughout a sequence of samples. Therefore regular measurements
of the reference solution within the sample sequence (see 9.1) are recommended. The fibre is still usable if
the method shows required sensitivity for substances under investigation.
Adding sodium chloride to the sample results in a clear improvement of the extraction yield for most
substances listed in Table 1. The addition of common salt (near saturation) is therefore recommended. Some
substances listed in Table 1 show a reverse effect, which in most cases is weaker. Salt additions of < 20 % of
the saturation concentration (e.g. about 0,5 g of NaCl in an 8 ml water sample) cause a deterioration in
reproducibility. It is important to keep to exactly the same salt additions for all samples of a calibration
sequence and/or sample sequence.
Salt deposits may accumulate in the metal syringe needle of the fibre holder after extended use. Salt deposits
always occur when the syringe needle of the fibre holder is immersed in the water sample during extraction.
This may damage the fibres and the injector liner. Therefore adjust the immersion depth precisely, and, if
necessary, rinse out the SPME syringe needle to dissolve any encrusted salt.
To ensure that the measurements are of high accuracy and precision, keep extraction time constant (e.g.
60 min) within a sample sequence for all samples. It is highly preferable to use an automatic sampler with an
SPME option.
For automatic operation, preferably use sampling vials with a thin septum (e.g. 0,9 mm to 1,3 mm thickness)
in order to avoid any mechanical problems when piercing the septum of the sample vial with the metal syringe
needle.
NOTE This is of particular importance when using automatic sampler systems that move sample vials in a circle,
because otherwise damage to the piercing metal syringe needle (including the exposed fibre) can occur during extraction.
Extraction of some of the substances listed in Table 1 using the procedure according to Clause 8 depends on
the temperature. As a rule, somewhat higher extraction yields are obtained at lower temperatures. Maintain
extraction temperature constant (e.g. 30 °C) within a sample sequence for all samples in order to obtain
reproducible extraction yields.
4.3 Interferences during gas chromatography and mass spectrometry procedure
Interferences may be caused, e.g. by the injection system used or by inadequate separation of the analytes.
Experienced operators, using the information given in the instrument manuals, may be able to minimise this
type of interference. Regular checking of the chromatographic and spectrometric system is required to
maintain adequate performance. Required system stability should be checked regularly by the use of a
GC standard.
Ascertain the necessary penetration depth for the fibres for thermal desorption in the GC injector. The
penetration depth corresponds to the hottest point of the injector and shall be kept constant during a
measuring sequence.
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SIST EN ISO 27108:2013
ISO 27108:2010(E)
5 Reagents
The reagents shall be free from impurities possibly interfering with the GC-MS analysis.
Use solvents and reagents of sufficient purity, i.e. with negligibly low impurities compared with the
concentration of analytes to be determined. As reagents, use, as far as available, “residual grade” or better in
order to obtain low blanks. Verify by blank determinations and, if necessary, apply additional cleaning steps.
5.1 Water, complying with the requirements of ISO 3696, grade 1 or equivalent.
5.2 Operating gases for the gas chromatograph-mass spectrometer, of high purity and in accordance
with manufacturer's specifications.
5.3 Sodium chloride, NaCl.
5.4 Solvents, e.g. ethyl acetate, C H O ; acetone (propanone), C H O; acetonitrile, CH CN.
4 8 2 3 6 3
For the preparation of stock solutions of individual reference substances (5.9.2) use the appropriate solvent.
However, it is recommended to prepare multi-component stock solutions (5.9.3) using either acetone or ethyl
acetate.
5.5 Sodium hydroxide solution, w(NaOH) = 25 % mass fraction.
5.6 Hydrochloric acid, w(HCl) = 25 % mass fraction or sulfuric acid, w(H SO ) = 12,5 % mass fraction.
2 4
5.7 Sodium thiosulfate pentahydrate, Na S O ·5 H O.
2 2 3 2
5.8 Internal standard, e.g. atrazine-d , lindane-d or parathion-ethyl-d .
5 6 10
As internal standard, choose a substance with similar physicochemical properties (extraction behaviour,
retention time) as the substance to be determined. The internal standard should not be present in the sample
to be analysed. The choice of a substance may be difficult and it depends on the problem to be resolved; in
any case, the suitability should be checked. It is highly recommended to use a deuterium-labelled or
13
C-enriched substance listed in Table 1 as an internal standard. It may be advantageous to use more than
one internal standard.
Prepare stock solutions of individual internal standard substances in the same way as specified for individual
reference substances (5.9.2).
5.9 Reference substances
5.9.1 General
Reference substances (listed in Table 1) of defined concentration suitable for both the preparation of stock
solutions and the preparation of spiked aqueous multi-component reference solutions used for calibration of
the total procedure (9.2).
5.9.2 Stock solutions of individual reference substances
As an example, place 50 mg of a reference substance into a 100 ml one-mark volumetric flask (6.6), dissolve
in an appropriate solvent (5.4) and make up to the mark with the same solvent.
Store stock solutions at temperatures between 1 °C and 5 °C according to ISO 5667-3, protected from light.
They are stable for at least 12 months.
NOTE Deep freezing of stock solutions is also possible and commonly applied.
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SIST EN ISO 27108:2013
ISO 27108:2010(E)
5.9.3 Multi-component stock solutions of reference substances
As an example, transfer 1 ml of each of the solutions of the individual substances (5.9.2) and the internal
standard substances (5.8) into a 100 ml one-mark volumetric flask (6.6) and make up to the mark with ethyl
acetate or acetone (5.4).
Store multi-component stock solutions at temperatures between 1 °C and 5 °C, protected from light. They are
stable for at least 6 months.
5.9.4 Aqueous multi-component reference solutions used for calibration of the total procedure
Prepare the aqueous reference solution for calibration of the total procedure as follows.
Measure 100 ml of water, e.g. in a one-mark volumetric flask (6.6) and add a magnetic stir bar.
Place the flask on a magnetic stirrer and switch on.
Using a microlitre syringe, measure 10 µl of the multi-component stock solution (5.9.3) and dispense it below
the surface of the stirred water. Continue to stir for about 5 min with the volumetric flask covered.
Adjust the agitation speed so that no turbulence funnel is formed.
Prepare reference solutions of higher and lower concentrations in the same way using correspondingly
prepared multi-component stock solutions (5.9.3). All aqueous reference solutions suitable for multipoint
calibration should contain equal amounts of internal standard.
Do not dilute the spiked aqueous solutions.
Always keep the spike volume constant.
NOTE A small spiking volume (e.g. 10 µl in 100 ml water) is recommended to avoid any interference of the solvent
within the fibre adsorption process of the analytes under investigation.
Store reference solutions at temperatures between 1 °C and 5 °C, protected from light. They may not be
stable for more than a few days and therefore shall be prepared each working day.
6 Apparatus
Equipment or parts of it which are likely to come into contact with the water sample or its extract shall be free
from residues causing interferences. The use of vessels made of glass, stainless steel or
polytetrafluoroethylene (PTFE) is recommended.
Usual laboratory equipment and in particular the following.
6.1 Sample flasks, e.g. brown glass, flat bottomed, with glass- or PTFE-coated stoppers, e.g. 100 ml or
250 ml.
6.2 Glass sample bottles (head space vials), with caps (6.3), e.g. 10 ml or 20 ml.
6.3 Crimp caps, with PTFE-coated septa (e.g. magnetic caps with butyl/PTFE septa, 0,9 mm to 1,3 mm).
NOTE Commercially available head space vials usually have a flanged rim suitable for a 3 mm septum. A thinner
septum (e.g. 0,9 mm to 1,1 mm) requires suitable vials with a thicker flanged rim. Alternatively, a perforated spacer ring
(e.g. made of natural rubber or butyl, 1,3 mm thick) can be placed between septum and crimp cap.
6.4 Crimper and decapper (e.g. manual crimper and manual decapper, 20 mm).
[3]
6.5 Graduated measuring cylinders, capacity, e.g. 100 ml or 250 ml, ISO 4788 class A.
[2]
6.6 One-mark volumetric flasks, capacity, e.g. 10 ml, 25 ml, 50 ml and 100 ml, ISO 1042 class A.
© ISO 2010 – All rights reserved 5
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SIST EN ISO 27108:2013
ISO 27108:2010(E)
[1]
6.7 Single volume pipettes, capacities between 1 ml and 50 ml, ISO 648 class A.
6.8 Microlitre syringes, e.g. capacities between 5 µl and 50 µl.
6.9 Magnetic stirrer, including PTFE-coated magnetic stir bar of suitable size.
6.10 Capillary gas chromatograph with mass spectrometric detector (GC-MS) using EI ionisation mode,
gas supply in accordance with the respective manufacturer's instructions.
6.11 Non-discriminating GC injector, e.g. splitless mode of a split or splitless injection system or
programmable temperature vaporiser (PTV).
6.12 Automatic sampler with SPME option, including SPME syringe and the necessary software.
6.13 SPME fibres, e.g. 10 mm medium polar polyacrylate-phases (PA coating: e.g. 85 µm) or bipolar
polydimethylsiloxane/divinylbenzene phases (PDMS/DVB coating: e.g. 65 µm). Other fibres as mentioned
above may be applicable as well. However, it is necessary to verify their sensitivity for the substances under
investigation (see 9.1).
NOTE Polyacrylate phases (PA 85) have proved to be most sensitive for the substances listed in Table 1.
Preferably use 23-gauge needles (particularly in combination with a septumless GC inlet system). If using a
septum type injection system, 24-gauge needles should be used to reduce septum coring.
6.14 Capillary columns, for gas chromatography (examples of chromatographs appear in Annex A). It is
advantageous t
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