SIST EN 16694:2015
(Main)Water quality - Determination of pentabromodiphenyl ether (PBDE) in whole water samples using solid phase extraction (SPE) with SPE-disks combined with gas chromatography - mass spectrometry (GC-MS)
Water quality - Determination of pentabromodiphenyl ether (PBDE) in whole water samples using solid phase extraction (SPE) with SPE-disks combined with gas chromatography - mass spectrometry (GC-MS)
Development of a method for the quantitative determination of PBDE congeners representative for the technical pentabromodiphenyl ether formulation in whole water samples using GC-MS.
The following congeners will be considered as specified in Directive 2008/105/EC:
- BDE28
- BDE47
- BDE99
- BDE100
- BDE153
- BDE154
This analytical method specifies the determination of PBDEs meeting the following requirements:
- The analysis of whole water samples containing up to 0,5 g/l of suspended solids;
- The limit of quantification (LOQ) shall be equal or less than 30 % of the EQS;
- The measurement uncertainty shall be equal or less than 50 %;
- The methods shall be fully in-house validated and tested for ruggedness prior to interlaboratory validation;
- A European interlaboratory comparison study will be conducted according to ISO 5725.
Wasserbeschaffenheit - Bestimmung von Pentabromdiphenylether (PBDE) in Gesamtwasserproben mittels Festphasenextraktion (SPE) mit SPE-Disks in Verbindung mit Gaschromatographie - Massenspektrometrie (GC-MS)
Diese Europäische Norm legt ein Verfahren für die Bestimmung von sechs ausgewählten polybromierten Diphenylethern (PBDE), repräsentativ für technisches pentaPBDE, in Wasserproben fest, wie in Tabelle 1 angegeben. Die Mindest-Bestimmungsgrenze für jedes einzelne Kongener in Gesamtwasserproben liegt bei Massenkonzentrationen von 0,025 ng/l. Die Bestimmungsgrenze (BG) sollte nach ISO/TS 13530 auf Grundlage von Mehrfachbestimmungen von Blindwertproben unter wiederholbaren Bedingungen bestimmt werden.) Das Verfahren nutzt die diskbasierte Festphasenextraktion SPE-Disk) in Kombination mit Gaschromatographie-Massenspektroskopie (GC MS). Die Norm gilt für die Analyse von PBDE in Oberflächenwasser mit einem Schwebstoffanteil bis zu 500 mg/l (Gesamtwasserproben), Trinkwasser und Grundwasser.
Dieses Verfahren kann für die Analyse weiterer BDE-Kongenere, die nicht in Tabelle 1 angegeben sind, oder andere Arten von Wasser angewendet werden, dies muss jedoch vorher verifiziert werden.
(...)
Qualité de l'eau - Dosage du pentabromodiphényléther (PBDE) dans la totalité de l'échantillon d'eau par extraction en phase solide (EPS) avec disques EPS, avec couplage chromatographie en phase gazeuse-spectrométrie de masse (CG-SM)
La présente Norme européenne spécifie une méthode pour le dosage des concentrations massiques ≥ 0,01 ng/l (pour chaque congénère individuel) d'une sélection de 6 éthers diphényliques polybromés (PBDE, voir Tableau 1) représentatifs du pentaBDE dans des échantillons d'eau. Cette méthode utilise une extraction en phase solide avec disques combinée à une chromatographie en phase gazeuse spectrométrie de masse (CG-SM). Elle s'applique à l'analyse des PBDE dans les eaux de surface, lesquelles peuvent contenir jusqu'à 500 mg/l (échantillons d'eau dans leur intégralité) de matières en suspension (MES), dans l'eau potable et dans les eaux souterraines.
Cette méthode peut être utilisée pour analyser d'autres congénères BDE non mentionnés dans le Tableau 1 ou d'autres types d'eau ; cependant, il est nécessaire de vérifier son applicabilité avant de l'employer.
Kakovost vode - Določevanje pentabromodifeniletra (PBDE) v celotnem vzorcu vode z ekstrakcijo na trdni fazi (SPE) s SPE-diski v kombinaciji s plinsko kromatografijo/masno spektrometrijo (GC/MS)
Razvoj metode za kvantitativno določevanje analogov pentabromodifeniletra, ki predstavljajo tehnično formulacijo pentabromodifeniletra v celotnih vzorcih vode z uporabo plinske kromatografije/masne spektrometrije (GC-MS).
V skladu z Direktivo 2008/105/ES se upoštevajo naslednji analogi:
– BDE28
– BDE47
– BDE99
– BDE100
– BDE153
– BDE154
Ta analitska metoda določa določevanje pentabromodifeniletrov, ki izpolnjujejo naslednje zahteve:
– analiza celotnih vzorcev vode, ki vsebujejo do 0,5 g/l trdnih delcev;
– meja določljivosti (LOQ) mora biti enaka ali manjša od 30 % EQS;
– merilna negotovost mora biti enaka ali manjša od 50 %;
– pred medlaboratorijskim potrjevanjem morajo biti metode v celoti preverjene interno in testirane glede robustnosti;
– evropska medlaboratorijska študijska primerjava bo potekala v skladu s standardom ISO 5725.
General Information
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Wasserbeschaffenheit - Bestimmung von Pentabromdiphenylether (PBDE) in Gesamtwasserproben mittels Festphasenextraktion (SPE) mit SPE-Disks in Verbindung mit Gaschromatographie - Massenspektrometrie (GC-MS)Qualité de l'eau - Dosage du pentabromodiphényléther (PBDE) dans la totalité de l'échantillon d'eau par extraction en phase solide (EPS) avec disques EPS, avec couplage chromatographie en phase gazeuse-spectrométrie de masse (CG-SM)Water quality - Determination of pentabromodiphenyl ether (PBDE) in whole water samples using solid phase extraction (SPE) with SPE-disks combined with gas chromatography - mass spectrometry (GC-MS)13.060.50VQRYLExamination of water for chemical substancesICS:Ta slovenski standard je istoveten z:EN 16694:2015SIST EN 16694:2015en,fr,de01-december-2015SIST EN 16694:2015SLOVENSKI
STANDARD
SIST EN 16694:2015
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 16694
September
t r s w ICS
s uä r x rä w r English Version
Water quality æ Determination of selected polybrominated using solid phase extractiocombined with gas chromatography æ mass spectrometry Qualité de l 5eau æ Dosage du pentabromodiphényléther avec couplage chromatographie en phase gazeuseæ Wasserbeschaffenheitt æ Bestimmung von in Gesamtwasserproben æ Verfahren mittels Verbindung mit Gaschromatographie æ This European Standard was approved by CEN on
t y June
t r s wä
egulations which stipulate the conditions for giving this European Standard the status of a national standard without any alterationä Upætoædate lists and bibliographical references concerning such national standards may be obtained on application to the CENæCENELEC Management Centre or to any CEN memberä
translation under the responsibility of a CEN member into its own language and notified to the CENæCENELEC Management Centre has the same status as the official versionsä
CEN members are the national standards bodies of Austriaá Belgiumá Bulgariaá Croatiaá Cyprusá Czech Republicá Denmarká Estoniaá Finlandá Former Yugoslav Republic of Macedoniaá Franceá Germanyá Greeceá Hungaryá Icelandá Irelandá Italyá Latviaá Lithuaniaá Luxembourgá Maltaá Netherlandsá Norwayá Polandá Portugalá Romaniaá Slovakiaá Sloveniaá Spainá Swedená Switzerlandá Turkey and United Kingdomä
EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre:
Avenue Marnix 17,
B-1000 Brussels
9
t r s w CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Membersä Refä Noä EN
s x x { vã t r s w ESIST EN 16694:2015
EN 16694:2015 (E) 2 Contents Page European foreword . 4 Introduction . 5 1 Scope . 6 2 Normative references . 6 3 Principle . 6 4 Interferences . 7 4.1 Interferences with extraction and clean up . 7 4.2 Interferences with GC-MS . 7 5 Reagents . 7 6 Apparatus . 10 7 Sampling . 11 8 Procedure. 11 8.1 Sample preparation . 11 8.2 Extraction by solid-phase extraction disks (SPE-disks) . 11 8.3 Solvent concentration. 12 8.4 Gas chromatrography and mass spectrometry . 12 8.5 Identification of individual compounds by means of GC-MS . 12 8.6 Blank value measurements . 14 9 Calibration . 15 9.1 Calibration with internal standards . 15 9.2 Procedure. 15 9.2.1 Evaluation of the range of linear relationship . 15 9.2.2 Two point calibration over the total linear range . 15 9.2.3 Estimation of the accuracy of the calibration for the concentration of interest . 16 10 Quantification . 17 10.1 Determination of the BDE concentrations in whole water samples . 17 10.2 Determination of the recoveries of the internal standards . 18 11 Expression of results . 18 12 Test report . 19 Annex A (informative)
Suitable gas chromatographic conditions and example chromatograms . 20 A.1 GC-HRMS conditions for the chromatograms in Figure A.1 . 20 A.2 GC-MS/MS conditions for the chromatograms in Figure A.2 . 23 A.3 GC-NCI-MS conditions for the chromatograms in Figure A.3 . 25 Annex B (informative)
Repeatability and reproducibility data . 26 Annex C (informative)
Examples of suitable solid phase extraction disks . 29 Annex D (informative)
Clean up procedure . 30 D.1 Reagents . 30 SIST EN 16694:2015
EN 16694:2015 (E) 3 D.2 Procedure . 30 Bibliography . 31
SIST EN 16694:2015
EN 16694:2015 (E) 4 European foreword This document (EN 16694:2015) has been prepared 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 March 2016, and conflicting national standards shall be withdrawn at the latest by March 2016. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association. 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 organisations 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. SIST EN 16694:2015
EN 16694:2015 (E) 5 Introduction WARNING — Persons using this European Standard should be familiar with usual laboratory practice. This European 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 European Standard be carried out by suitably trained staff. Polybrominated diphenyl ethers (PBDE) are priority substances listed in Annex X of the EU Water Framework Directive (WFD, Directive 2000/60/EC) for which environmental quality standards (EQS) have been set at EU level for inland waters as well as other surface waters to protect the aquatic environment against chemical pollution (Directive 2008/105/EC). With the exception of metals, the EQS are expressed as total concentrations in the whole water sample. Furthermore, analytical methods used in WFD monitoring need to meet certain requirements as regards the minimum limit of quantification and the maximum tolerable measurement uncertainty (Directive 2009/90/EC). So far, there is no standardized method available for the determination of PBDE in whole water samples fulfilling those requirements. Hence, the European Commission mandated CEN to develop or improve standards in support of the implementation of the monitoring requirements of WFD. Directive 2008/105/EC has been amended by Directive 2013/39/EU, however this standard has been developed for the analysis of PBDE as listed in Annex A of Directive 2008/105/EC. The priority substances list in Annex X of the WFD includes technical pentabromodiphenyl ether, which is regarded as a mixture of the congeners BDE-28, BDE-47, BDE-99, BDE-100, BDE-153 and BDE-154. The annual average environmental quality standard (AA-EQS) for pentabromodiphenyl ether in inland surface waters is 0,5 ng/l and is defined for the whole water sample including suspended particulate matter (SPM) present in the sample. Compounds such as PBDE strongly adsorb to environmental solids resulting in a fraction bound to particles, which may be substantial. The aim of the method is to extract whole water samples in one single step to determine the dissolved as well as the particle bound PBDE fraction. Identification and quantification of BDE congeners at trace level concentrations require both highly sensitive chromatographic equipment and effective enrichment steps and awareness of the potential impact of blanks. SIST EN 16694:2015
EN 16694:2015 (E) 6 1 Scope This European Standard specifies a method for the determination of six selected polybrominated diphenyl ethers (PBDE) listed in Table 1, representative for technical brominated diphenyl ethers (BDE) in water samples in mass concentrations
0,025 ng/l for each individual congener. The method uses solid-phase extraction with SPE-disks in combination with gas chromatography-mass spectrometry (GC-MS). It is applicable to the analysis of PBDE in surface water containing suspended particulate matter (SPM) up to 500 mg/l (whole water samples), drinking water and groundwater. The limit of quantification (LOQ) was determined according to ISO/TS 13530, on the basis of replicate determinations of the procedural blank, carried out under reproducibility conditions. This method may be used for the analysis of other BDE congeners not listed in Table 1 or other types of water. However, it is important to verify its applicability before use. Table 1 — Polybrominated diphenyl ethers (PBDE) determined by this method Congener Abbreviationa Formula Molar mass CAS RNb
g/mol
2,4,4’-Tribromodiphenyl ether BDE-28 C12H7Br3O 406,8954 41318–75–6 2,2’,4,4’-Tetrabromodiphenyl ether BDE-47 C12H6Br4O 485,7950 5436–43–1 2,2’,4,4’,5-Pentabromodiphenyl ether BDE-99 C12H5Br5O 564,6911 60348–60–9 2,2’,4,4’,6-Pentabromodiphenyl ether BDE-100 C12H5Br5O 564,6911 189084–64–8 2,2’,4,4’,5,6’-Hexabromodiphenyl ether BDE-154 C12H4Br6O 643,5872 68631–49–2 2,2’,4,4’,5,5’-Hexabromodiphenyl ether BDE-153 C12H4Br6O 643,5872 207122–15–4 NOTE EC numbers are not applicable for PBDE congeners. a Numbering analog to IUPAC nomenclature for PCB b CAS RN: Chemical Abstracts Service Registry Number 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN ISO 3696, Water for analytical laboratory use - Specification and test methods (ISO 3696) EN ISO 5667-1, Water quality - Sampling - Part 1: Guidance on the design of sampling programmes and sampling techniques (ISO 5667-1) EN ISO 5667-3, Water quality - Sampling - Part 3: Preservation and handling of water samples (ISO 5667-3) ISO 8466-1, Water quality — Calibration and evaluation of analytical methods and estimation of performance characteristics — Part 1: Statistical evaluation of the linear calibration function 3 Principle A mixture of suitable internal standards (13C12-labelled BDE or fluorinated BDE) is added to a 1 l water sample, which is then extracted using a solid-phase extraction disk (SPE-disk). The disk is eluted with a SIST EN 16694:2015
EN 16694:2015 (E) 7 suitable solvent (5.4) or solvent mixture and the resulting extract is concentrated for analysis or further clean-up. Prior to injection, an injection standard is added to each extract, and an aliquot is injected into the gas chromatograph. The analytes are separated by capillary gas chromatography and detected and quantified by electron ionization high-resolution mass spectrometry (EI-HRMS) or alternatively, by low resolution negative chemical ionization mass spectrometry (NCI-MS) or low resolution tandem mass spectrometry (MS/MS). In the latter cases a clean-up step using e. g. a multilayer-silica column, and/or removal of sulfur, e. g. by gel permeation chromatography, may be necessary. 4 Interferences 4.1 Interferences with extraction and clean up To avoid interference, collect samples as specified in Clause 7. Commercially available SPE-disks can differ frequently in quality. Variations in the selectivity of the materials can occur from batch to batch, and therefore might cause significant deviations in extraction yield. This does not basically impair their suitability, apart from a resulting higher detection limit of individual substances. To ensure that the analytical results have a high accuracy and precision, use materials from one batch for both measurement and calibration. Avoid major fluctuations in the extraction times and elution procedures within one sample sequence when analysing the samples. 4.2 Interferences with GC-MS Interferences may be caused, e. g. by the injection system used or by inadequate separation of the analytes. Experienced operators might be able to minimize 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 using a GC standard. 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 to grade 1 according to EN ISO 3696, or equivalent. 5.2 Operating gases for the gas chromatography mass spectrometry, of high purity and according to the manufacturer's specifications. 5.3 Nitrogen of high purity, i.e. minimum 99,996 % by volume, for concentration by evaporation. 5.4 Solvents for extraction, chromatography and preparation of reference solutions. A variety of solvents may be used depending on the procedural step and the availability of commercial stock solutions, e. g. — toluene, C7H8 (boiling point: 111 °C), — acetone, C3H6O (boiling point: 56 °C), — iso- or n-hexane, C6H14, (boiling point: 60 °C), SIST EN 16694:2015
EN 16694:2015 (E) 8 — iso-octane (2,2,4-trimethylpentane), C8H18 (boiling point: 99 °C), — nonane, C9H20 (boiling point: 151 °C), — dichloromethane, CH2Cl2, (boiling point: 39,7 °C), — ethyl acetate, C4H8O2 (boiling point: 77 °C), — iso-propanol, C3H8O (boiling point: 82 °C) for residual analysis. A suitable keeper is recommended (e. g. toluene), when reducing the volume of the extract to less than 0,5 ml. For large volume injection a more volatile solvent, e. g. hexane, should be used. 5.5 Clean up material, according to Annex C. 5.6 Sodium sulfate, anhydrous, Na2SO4, powdered. 5.7 Standards 5.7.1 Reference substances PBDE listed in Table 1 are used for calibration. Solutions of the reference substances are commercially available. 5.7.2 Internal standards Solutions of reference substances for use as internal standards for electron impact ionization (see Table 2) are commercially available. Table 2 — Examples of internal standards for GC-EI-MS analysis Standard Abbreviation Formula Molar mass g/mol 2,4,4’-Tribromo[13C12]diphenyl ether 13C-BDE-28 13C12H7Br3O 418,8038 2,2’,4,4’-Tetrabromo[13C12]diphenyl ether 13C-BDE-47 13C12H6Br4O 497,7035 2,2’,4,4’,5-Pentabromo[13C12]diphenyl ether 13C-BDE-99 13C12H5Br5O 576,5995 2,2’,4,4’,5,5’-Hexabromo[13C12]diphenyl ether 13C-BDE-153 13C12H4Br6O 655,4955 Solutions of reference substances for use as internal standards for negative ion chemical ionization (see Table 3) are commercially available. SIST EN 16694:2015
EN 16694:2015 (E) 9 Table 3 — Examples of internal standards for GC-NCI-MS analysis Standard Abbreviation Formula Molar mass g/mol 2-Fluoro-2,4,4’-tribromodiphenyl ether F-BDE-28 C12H6Br3OF 424,8858 6-Fluoro-2,2’,4,4’-tetrabromodiphenyl ether F-BDE-47 C12H5Br4OF 503,7819 3-Fluoro-2,2’,4,4’,6-pentabromodiphenyl ether F-BDE-100 C12H4Br5OF 582,6779 4’-Fluoro-2,3,3’,4,5,6-hexabromodiphenyl ether F-BDE-160 C12H3Br6OF 661,5740 5.7.3 Injection standard To determine recovery rates for the internal standards in each sample e. g. dibromooctafluorobiphenyl (C12Br2F8) is used as an injection standard. 5.7.4 Preparation of standard stock solutions 5.7.4.1 Stock solutions of the single reference substances/internal standards Use either commercially available solutions or prepare stock solutions by dissolving e. g. 10 mg of each of the reference substances in toluene (5.4) in a 100 ml volumetric amber flask and bring to volume, resulting in a final concentration of 100 µg/ml. Correct the concentration for purity if this is < 99 %. Store stock solutions at temperatures between 1°C and 5°C according to EN ISO 5667-3, protected from light. They are stable for at least 12 months. 5.7.4.2 Stock solution of the injection standard Use a commercially available solution or prepare a stock solution by dissolving e. g. 10 mg of the reference substance in toluene (5.4) in a 100 ml volumetric amber flask and bring to volume, resulting in a final concentration of 100 µg/ml. Make appropriate dilutions in hexane or toluene allowing to spike e. g. 100 pg accurately to the final extract of a water sample. Store stock solutions at temperatures between 1°C and 5°C according to EN ISO 5667-3, protected from light. They are stable for at least 12 months. 5.7.4.3 Multicomponent stock solution of reference substances Accurately transfer between 100 µl to 500 µl of each single standard solution (5.7.4.1) into a 10 ml volumetric amber flask and bring to volume, resulting in final concentrations between 1 µg/ml and 5 µg/ml per substance. Store multicomponent stock solutions at temperatures between 1 °C and 5 °C, protected from light. They are stable for at least 6 months. 5.7.4.4 Multicomponent stock solution of internal standards Prepare a stock solution of the internal standards (5.7.4.1) at an appropriate concentration in hexane or toluene (e. g. 1 ng/ml). Store multicomponent stock solutions at temperatures between 1°C and 5°C, protected from light. They are stable for at least 6 months. 5.7.4.5 Calibration control standard solution Use a commercially available standard solution of reference substances from an independent supplier or prepare an independent standard solution from the pure reference substances. Store the calibration control standard solution at temperatures between 1°C and 5°C, protected from light. It is stable for at least 6 months. SIST EN 16694:2015
EN 16694:2015 (E) 10 6 Apparatus Equipment or parts of it which have 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. To minimize the blank contribution the vessels shall be rinsed with organic solvent prior to use. 6.1 Sample flasks, e. g. brown glass, flat bottomed, with glass or PTFE coated stoppers, e. g. 1 000 ml or 2 000 ml. 6.2 One-mark volumetric flasks, capacity e. g. 10 ml, 25 ml, 50 ml and 100 ml. 6.3 Single volume pipettes, capacities between 1 ml and 50 ml. 6.4 Capillary gas chromatograph with high resolution mass spectrometric detector using electron ionization (GC-HRMS), or capillary gas chromatograph with mass spectrometric detector using chemical ionization in negative mode (GC-NCI-MS).
The gas supplies shall be in accordance with the respective manufacturer's instructions. 6.5 Non-discriminating GC injector, e. g. splitless mode of a split/splitless injection system or programmable temperature vaporizer (PTV), programmable for large volume injection (LVI). A cold injection technique is recommended; depending on the sensitivity of the instrument large volume injection may be necessary. 6.6 Automatic sampler with option for large volume injection (LVI), including syringes for normal injection (e. g. 1 µl and 2 µl) and for LVI (e. g. 10 µl, 50 µl and 100 µl). 6.7 Capillary columns, for gas chromatography (example chromatograms are given in Annex A). It is advantageous to use non-polar columns (e. g. low-bleed 5 %-phenylsiloxane column), providing thermal stability up to 400 °C; e. g. inner diameter
0,25 mm, length 15 m, film thickness of 0,1 µm is recommended. 6.8 Solid-phase extraction disks (SPE-disks), wide inner diameter: e. g. 40 mm to 60 mm, packed with an appropriate reversed phase adsorbent material, e. g. C18-based or SDB-based adsorbent (for examples, see Annex C). 6.9 Vacuum device for solid-phase extraction, e. g. extraction box or automated workstation for solid-phase extraction procedure capable for processing SPE-disks. 6.10 Evaporation device, such as rotary evaporator, turboevaporator or vacuum concentration device. 6.11 Syringes, 2 µl, 5 µl, 10 µl and 50 µl, volume precision ± 2 %. 6.12 Sample vials; amber glass with fluoropolymer-lined screw-cap is most suitable. 6.13 Glass columns for chromatographic clean-up. 6.14 Pasteur pipettes, made of glass. SIST EN 16694:2015
EN 16694:2015 (E) 11 7 Sampling Collect samples as specified in EN ISO 5667-1 and EN ISO 5667-3. For sampling, use thoroughly cleaned, flat bottomed glass flasks (6.1). Fill the bottles completely with the water to be examined. Treat and analyze the samples after sample collection as specified in EN ISO 5667-3. Store the samples at temperatures between 1°C and 5°C, protected from light. Carry out the extraction procedure within 3 weeks. 8 Procedure 8.1 Sample preparation In general, samples are examined without pre-treatment, e. g. suspended particulate matter is not removed prior to analysis. Do not filter the sample. Large particles (e. g. leaves, little branches) should be removed using a sieve (screening gap 1 mm). Add a precisely defined amount of the internal standard stock solution (5.7.4.4) to e. g. 1 000 ml of whole water sample; typically the concentration of the internal standards in the water sample is ca. 100 pg/l. Calculate the exact volume of the water sample by accurately weighing the sample container before extraction and after emptying the sample container. It is recommended to add the internal standard stock solution (5.7.4.4) first to a water miscible solvent, e. g. 10 ml isopropanol, which is subsequently added to the water sample. 8.2 Extraction by solid-phase extraction disks (SPE-disks) For conditioning of SPE-disks add an amount of acetone (6 ml to10 ml) and let it pass through the disk in about 20 s, e. g. using a vacuum device. Ensure that the adsorbent does not run dry. Repeat this step once. Add an amount of water (6 ml to10 ml) and let it pass through the disk in about 20 s, e. g. using a vacuum device. Ensure that the adsorbent does not run dry. Repeat this step once. For sample loading and extraction of analytes dissolved in the water phase take, for example, 1 000 ml of the sample to be examined (8.1) and pass it through the disk conditioned as described above at a flow rate of about 50 ml/min. For transferring particulate matter on the disk that might have remained in the bottle, rinse the sample reservoir (e. g. the sample bottle) twice with approximately 9 ml of water and pass it through the disk as described above. Dry the disk using a vacuum device (6.9) or by a gentle stream of nitrogen (5.3) for about 10 min to 15 min. Perform the extraction and elution as follows. Add an amount of acetone (6 ml to 10 ml), allowing 5 min for the solvent to soak. Collect the eluate by passing it through the disk in about 20 s. Add an amount of acetone (4 ml to 8 ml), allowing 5 min for the solvent to soak. Collect the eluate by passing it through the disk in about 20 s. Repeat this step twice. Collect the combined eluates in a glass vessel. Carefully evaporate the solvent and concentrate the eluate as specified in 8.3. SIST EN 16694:2015
EN 16694:2015 (E) 12 Other solvents may be used for extraction and elution. However, their suitability should be established in preliminary tests with blank water samples spiked with certified sediment up to 500 mg/l and processed according to Clause 8. Recoveries for each substance under investigation should be > 70 % and
120 %. To obtain sufficiently high absolute recoveries it is essential to dry the disk completely prior to elution or to use a water removing solvent in the first elution step. 8.3 Solvent concentration Add a defined amount of injection standard (e. g. dibromooctafluorobiphenyl) dissolved in solvent, e. g. hexane or toluene (5.4), and concentrate the SPE eluate (see 8.2) carefully to a final volume of about 0,5 ml to 1,0 ml (e. g. in a gentle stream of nitrogen (5.3) or on a rotary evaporator under reduced pressure). To achieve a higher sensitivity, solvent evaporation can be continued to smaller final volumes (e.g. 0,1 ml).The temperature of the eluate during concentration shall be kept below 30 °C. In some cases and especially when using GC-NCI-MS or GC-MS/MS detection a clean-up step might be necessary to remove interfering compounds as follows. Concentrate the SPE eluate (see 8.2) carefully to 1 ml to 2 ml, add 20 ml of hexane (5.4) and continue to concentrate. Repeat this step once in order to remove as much acetone as possible. If necessary dry the extract with Na2SO4. Proceed with a clean-up (see Annex D for an example) and concentrate the eluate obtained in the clean-up step to a final volume as described above. 8.4 Gas chromatrography and mass spectrometry Optimize the operating conditions of the GC-MS system e. g. according to the manufacturer’s instructions. Examples of suitable gas chromatographic conditions are given in Annex A. Prior to analysis, establish the operating conditions and verify the GC-MS system performance and the calibration for all analytes and their
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