ISO-22155-2005.pdf

Reference number ISO 22155:2005(E) © ISO 2005 INTERNATIONAL STANDARD ISO 22155 First edition 2005-10-01 Soil quality Gas chromatographic quantitative determination of volatile aromatic and halogenated hydrocarbons and selected ethers Static headspace method Qualité du sol Dosage des hydrocarbures aromatiques et halogénés volatils et de certains éthers par chromatographie en phase gazeuse Méthode par espace de tête statique ISO 22155:2005(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. 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ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii © ISO 2005 All rights reserved -,-,- ISO 22155:2005(E) © ISO 2005 All rights reserved iii Contents Page Foreword iv 1 Scope . 1 2 Normative references. 1 3 Principle. 2 4 Reagents 2 5 Apparatus 5 6 Sampling, preservation and sample pre-treatment. 6 7 Procedure 6 8 Calculation. 10 9 Expression of results . 10 10 Precision 10 11 Report 11 Annex A (informative) Relative retention times with respect to ethylbenzene-D10 of volatile aromatic hydrocarbons and volatile halogenated hydrocarbons on following columns: CP-Sil 5 CB and CP-Sil 13 CB 12 Annex B (informative) Validation 13 Bibliography. 17 ISO 22155:2005(E) iv © ISO 2005 All rights reserved 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 22155 was prepared by Technical Committee ISO/TC 190, Soil quality, Subcommittee SC 3, Chemical methods and soil characteristics. -,-,- INTERNATIONAL STANDARD ISO 22155:2005(E) © ISO 2005 All rights reserved 1 Soil quality Gas chromatographic quantitative determination of volatile aromatic and halogenated hydrocarbons and selected ethers Static headspace method 1 Scope This International Standard specifies a static headspace method for quantitative gas chromatographic determination of volatile aromatic and halogenated hydrocarbons and selected aliphatic ethers in soil. This International Standard is applicable to all types of soil. The limit of determination is dependent on the detection system used and the quality of the methanol grade used for the extraction of the soil sample. Under the conditions specified in this International Standard, the following limits of determinations apply (expressed on the basis of dry matter): a) when using gas chromatography with a flame ionization detector (GC-FID), the typical limit of determination is 0,2 mg/kg for volatile aromatic hydrocarbons and 0,5 mg/kg for aliphatic ethers as methyl tert-butyl ether (MTBE) and tert-amyl methyl ether (TAME); b) when using gas chromatography with an electron capture detector (GC-ECD), the typical limit of determination is 0,01 mg/kg to 0,2 mg/kg for volatile halogenated hydrocarbons. NOTE Lower limits of determination can be achieved by using mass spectrometry (MS) with selected ion detection. 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 10381-1, Soil quality Sampling Part 1: Guidance on the design of sampling programmes ISO 10381-2, Soil quality Sampling Part 2: Guidance on the design of sampling techniques ISO 11465, Soil quality Determination of dry matter and water content on a mass basis Gravimetric method ISO 15680, Water quality Gas-chromatographic determination of a number of monocyclic aromatic hydrocarbons, naphthalene and several chlorinated compounds using purge-and-trap and thermal desorption ISO 228921), Soil quality Guidelines for the identification of target compounds by gas chromatography and mass spectrometry 1) To be published. ISO 22155:2005(E) 2 © ISO 2005 All rights reserved 3 Principle Test samples are taken from an untreated field moist soil sample. To prevent losses of the volatiles, samples are taken as undisturbed as possible in the field and methanol is added immediately. The test sample is extracted with methanol. An aliquot of the methanol extract is transferred into a headspace vial with a defined amount of water and sealed. The temperature of the vials is stabilized in a thermostatic system to a temperature within the range 50 °C to 80 °C to achieve specified equilibrium conditions. Gas chromatographic analysis of the volatile compounds in gaseous phase in equilibrium with the water in the vials is carried out by using headspace injection and an appropriate capillary column. Volatile organic compounds are detected with appropriate detectors such as, a mass spectrometric detector (MS), a flame ionization detector (FID), an electron capture detector (ECD), a photo-ionization detector (PID) or an electrolytic conductivity detector (ELCD). Identification and quantification is made by comparison of retention times and peak heights (or peak areas) comparing to the internal standard added. When using non-specific detectors such as FID and ECD, the confirmation of the identity of the detected compounds and their concentrations should be done by repeating the gas chromatographic analysis, using a column of different polarity. When using gas chromatography-mass spectrometry (GC-MS), the identity confirmation and the quantification can be done in a single run. NOTE Other injection technique such as purge and trap followed by thermal desorption or solid phase micro- extraction (SPME) can be used, provided that their applicability is proven. 4 Reagents All reagents shall be of recognised analytical grade. Verify whether the reagents are applicable for this specific purpose and are free of interfering compounds. 4.1 Water, free of volatile organic compounds, showing negligible interferences in comparison with the smallest concentration to be determined. A sufficient amount of water from the same batch should be available to complete each batch of analyses, including all preparations. 4.2 Internal standard compounds, which do not interfere with the compounds present in the methanol extract. For the determination of volatile aromatic hydrocarbons and volatile halogenated hydrocarbons, preferably two internal standards shall be selected. 4.2.1 Examples of suitable internal standards are: Toluene-D8 (CAS No. 2037-26-5) Ethylbenzene-D10 (CAS No. 25837-05-2) 2-Bromofluorobenzene (CAS No. 1072-85-1) 4.2.2 Examples of suitable internal standards are: 1,4-Dichlorobutane (CAS No. 110-56-5) ,-Trifluorotoluene (CAS No. 98-08-8) 2-Bromofluorobenzene (CAS No. 1072-85-1) ISO 22155:2005(E) © ISO 2005 All rights reserved 3 4.3 Volatile aromatic hydrocarbons Compound CAS No. Benzene 71-43-2 Toluene 108-88-3 Ethylbenzene 100-41-4 o-Xylene 95-47-6 m-Xylene 108-38-3 p-Xylene 106-42-3 Styrene 100-42-5 Naphthalene 91-20-3 4.4 Volatile halogenated hydrocarbons Compound CAS No. Dichloromethane 75-09-2 Trichloromethane 67-66-3 Tetrachloromethane 56-23-5 1,1-Dichloroethane 75-34-3 1,2-Dichloroethane 107-06-2 1,1,1-Trichloroethane 79-01-6 1,1,2-Trichloroethane 79-00-5 1,2-Dichloropropane 78-87-5 1,2,3-Trichloropropane 98-18-4 cis-1,3-Dichloropropene 10061-01-5 trans-1,3-Dichloropropene 10061-02-6 cis-1,2-Dichloroethene 156-59-2 trans-1,2-Dichloroethene 156-60-5 3-Chloropropene 107-05-1 Trichloroethene 79-01-6 Tetrachloroethene 127-18-4 Monochlorobenzene 108-90-7 1,2-Dichlorobenzene 95-50-1 4.5 Aliphatic ethers Compound CAS No. methyl tert-butyl ether (MTBE) 1634-04-4 tert-amyl methyl ether (TAME) 994-05-8 NOTE This method can also be used for volatile organic compounds not included in this International Standard, provided it has been validated for each new compound. -,-,- ISO 22155:2005(E) 4 © ISO 2005 All rights reserved 4.6 Methanol (CAS-No. 67-56-1), as a solvent for the extraction of soil samples and for the preparation of standard solutions. NOTE Other solvents which are readily soluble in water and do not interfere with the analytical process can be used as well, for example dimethylformamide (DMF) and dimethylsulfoxide (DMSO). 4.7 Carrier gases for gas chromatography, nitrogen or argon-methane mixture ultrapure. Other gases for gas chromatography shall be used in accordance with the instrument manufacturer's instructions. 4.8 Standard solutions 4.8.1 Standard stock solutions for the volatile compounds in methanol Prepare the stock solutions by adding defined amounts (e.g. 100 µl) of each standard compound (4.3 and 4.4) with a microlitre syringe. Immerse the tip of the needle in the solvent methanol and weigh with an accuracy of 0,1 mg. NOTE 1 A convenient concentration (4 mg/ml) of the standard stock solution is obtained by weighing 100 mg of the standard substance and dissolving it in 25 ml of the solvent. The solution is stable for about 6 months when stored at 18 °C. NOTE 2 For practical reasons, mixed standard stock solutions can also be prepared. 4.8.2 Internal standard stock solutions in methanol Prepare the internal standard stock solutions with the individual internal standard compounds (4.2.1 and 4.2.2) in the same manner as in 4.8.1. The containers containing the solutions shall be marked or weighed so that any evaporation losses of the solvent may be recognised. The solutions shall be stored in volumetric flasks with ground glass stoppers at a temperature of 4 °C ± 2° C in the dark. Prior to use, they shall be brought to ambient temperature. 4.8.3 Intermediate mixed standard solutions Prepare intermediate mixed standard solutions by mixing a defined volume of each individual standard stock solution or a mixed standard stock solution and dilute with methanol. NOTE A typical concentration is 40 µg/ml. Store the intermediate mixed standard solutions at 4 °C ± 2° C not longer than 3 months. 4.8.4 Working standard solutions Prepare at least five different concentrations (e.g. from 0,2 µg/ml to 3,2 µg/ml) by suitable dilutions of the intermediate mixed standard solutions. Add 50 µl to 500 µl of these concentrations to 10 ml of methanol using a microlitre syringe. 4.8.5 Working internal standard solutions Prepare the working internal standard solutions of defined concentration (e.g. 0,4 µg/ml) as described in 4.8.3 and 4.8.4. 4.8.6 Aqueous calibration standard solutions Prepare the calibration solutions (see Table 1) by adding a defined amount (e.g. 50 µl) of working standard solutions and internal standard solutions to a defined volume (e.g. 10 ml) of water in an appropriate headspace vial. Use a syringe and immerse the top of the needle in the water. Seal the vial tightly with a crimp cap fitted with polytetrafluoroethylene (PTFE) coated septum. The total volume of the methanol used for ISO 22155:2005(E) © ISO 2005 All rights reserved 5 calibration shall be the same as for extraction of the soil sample. Make sure that the content of the organic solvent in the final aqueous calibration standard solution does not exceed 2 % (volume fraction). Table 1 Example for the preparation of calibration solutions Calibration solution Working standard solutions (4.8.4) Working internal standard solutions (4.8.5) Concentration in working standard solution Quantity in calibration solution of 10 ml (sample) water Concentration in aqueous calibration solution µl µl µg/ml ng µg/l 1 50 50 (methanol) 0 0 0 2 50 50 0,2 10 1 3 50 50 0,4 20 2 4 50 50 0,8 40 4 5 50 50 1,6 80 8 6 50 50 3,2 160 16 5 Apparatus Usual laboratory glassware, free of interfering compounds. All glassware shall be cleaned according to the usual procedures for this type of analysis. 5.1 Glass vials, with suitable septum, fitted with a PTFE-coated septum, capable of being hermetically sealed in the field as well as at elevated temperatures. Glass vials (50 ml to 100 ml) with screw caps, for field moist soil samples taken in the field. Glass vials (10 ml for 5 ml water and 22 ml for 10 ml water) with crimped metallic caps, compatible with the headspace system, connected to an appropriate gas chromatographic system. 5.2 Crimping pliers 5.3 Headspace system This method was developed for using a totally automated equilibrium headspace analyser available from several commercial sources. The system used shall meet the following specifications. The system shall be capable of keeping the vials at a constant temperature (between 50 °C and 80 °C), and transferring accurately a representative portion of the headspace into a gas chromatograph fitted with capillary columns. 5.4 Shaking machin