1、 ISO 2012 Soil quality Determination of linear alkylbenzene sulfonate (LAS) Method by HPLC with fluorescence detection (LC-FLD) and mass selective detection (LC-MSD) Qualit du sol Dtermination des sulfonates dalkyl benzne linaires (SAL) Mthode par chromatographie liquide haute performance (CLHP) ave
2、c dtection par fluorescence (CL-DFL) et dtection slective de la masse (CL-DSM) TECHNICAL SPECIFICATION ISO/TS 13896 First edition 2012-09-01 Reference number ISO/TS 13896:2012(E) ISO/TS 13896:2012(E) ii ISO 2012 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2012 All rights reserved. Unless ot
3、herwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyri
4、ght 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 ISO/TS 13896:2012(E) ISO 2012 All rights reserved iii Contents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references 1 3 Terms and d
5、efinitions . 1 4 Principle 2 5 Interferences 2 5.1 Interferences from sampling. 2 5.2 Interferences by HPLC-FLD and HPLC-MS 2 6 Reagents 3 7 Apparatus . 5 8 Sample storage and sample pretreatment 6 8.1 Sample storage 6 8.2 Sample pretreatment . 6 9 Procedure. 6 9.1 Extraction 6 9.2 Concentration (op
6、tional) 7 9.3 Clean-up (optional) . 7 9.4 Blank test . 7 9.5 HPLC analysis . 7 9.6 Calibration 8 10 Calculation and expression of results . 9 10.1 General . 9 10.2 Calibration .10 10.3 Calculation .10 11 Precision 11 12 Test report 11 Annex A (informative) Repeatability and reproducibility data .12
7、Annex B (informative) Examples of chromatographic conditions and chromatograms .14 Annex C (informative) Examples of clean-up procedures .17 Bibliography .18 ISO/TS 13896:2012(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
8、(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, g
9、overnmental 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/I
10、EC 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 mem
11、ber bodies casting a vote. In other circumstances, particularly when there is an urgent market requirement for such documents, a technical committee may decide to publish other types of document: an ISO Publicly Available Specification (ISO/PAS) represents an agreement between technical experts in a
12、n ISO working group and is accepted for publication if it is approved by more than 50 % of the members of the parent committee casting a vote; an ISO Technical Specification (ISO/TS) represents an agreement between the members of a technical committee and is accepted for publication if it is approve
13、d by 2/3 of the members of the committee casting a vote. An ISO/PAS or ISO/TS is reviewed after three years in order to decide whether it will be confirmed for a further three years, revised to become an International Standard, or withdrawn. If the ISO/PAS or ISO/TS is confirmed, it is reviewed agai
14、n after a further three years, at which time it must either be transformed into an International Standard or be withdrawn. 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 al
15、l such patent rights. ISO/TS 13896 was prepared by Technical Committee ISO/TC 190, Soil quality, Subcommittee SC 3, Chemical methods and soil characteristics. iv ISO 2012 All rights reserved ISO/TS 13896:2012(E) Introduction The anionic surfactant LAS (Linear Alkylbenzene Sulfonate) is found in the
16、environment due to its use in detergents. For more than 30 years, LAS has been the largest single surfactant used in detergents, and the use continues on a high level. Although LAS is readily biodegradable during wastewater treatment, considerable amounts may still be found in sludge of municipal or
17、igin. By the use of sludge for soil improvement, LAS can end up in agricultural soil, where a rapid biodegradation takes place. The method describes the determination of LAS in sludge, soil, treated biowaste and neighbouring fields. LAS is the sodium salt of alkylbenzene sulfonic acids, and it consi
18、sts of a mixture of the homologues C 10 - LAS, C 11 -LAS, C 12 -LAS, C 13 -LAS and C 14 -LAS. LAS is determined as the sum of the homologues. This Technical Specification is applicable and validated for several types of matrices as indicated in Table 1 (see also Annex A for the results of the valida
19、tion). Table 1 Matrices for which this Technical Specification is applicable and validated Matrix Materials used for validation Sludge Municipal sewage sludge Biowaste Fresh compost Soil Sludge amended soil ISO 2012 All rights reserved v Soil quality Determination of linear alkylbenzene sulfonate (L
20、AS) Method by HPLC with fluorescence detection (LC-FLD) and mass selective detection (LC-MSD) WARNING Persons using this Technical Specification should be familiar with usual laboratory practice. This Technical Specification does not purport to address all of the safety problems, if any, associated
21、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 Technical Specification be carried out by suitably tra
22、ined staff. 1 Scope This Technical Specification specifies a method for the determination of linear alkylbenzene sulfonate (LAS) in sludge, treated biowaste and soil using high-performance liquid chromatography (HPLC) with a fluorescence detector (FLD) or a mass selective detector (MSD). This Techni
23、cal Specification specifies the determination of the sum of LAS. Under the conditions specified in this Technical Specification, typically a limit of detection of 20 mg/kg (expressed as dry matter) for sludge and of 0,2 mg/kg to 0,5 mg/kg for soil and treated biowaste may be achieved. Lower limits o
24、f detection may be achieved by concentrating the extract by solvent evaporation. NOTE The single LAS homologues C 10to C 14can be determined by this Technical Specification. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated re
25、ferences, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 8466-1, Water quality Calibration and evaluation of analytical methods and estimation of performance characteristics Part 1: Statistical evaluation
26、of the linear calibration function ISO 11465, Soil quality Determination of dry matter and water content on a mass basis Gravimetric method ISO 14507, Soil quality Pretreatment of samples for determination of organic contaminants ISO 22892, Soil quality Guidelines for the identification of target co
27、mpounds by gas chromatography and mass spectrometry 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 analyte mixture of homologues (i.e. C 10 -LAS, C 11 -LAS, C 12 -LAS, C 13 -LAS and C 14 -LAS) where each homologue consists of a mixture of fo
28、ur to six isomers depending on the length of the alkyl group NOTE The dominant homologues in detergents and environmental samples are C 11 -LAS and C 12 -LAS. C 10to C 14refers to the chain length of the linear alkyl group. TECHNICAL SPECIFICATION ISO/TS 13896:2012(E) ISO 2012 All rights reserved 1
29、ISO/TS 13896:2012(E) 4 Principle After pretreatment, the test sample is extracted by shaking with methanol. If necessary, interfering compounds are removed from the extract by a clean-up on a suitable column. The extract is analysed by high-performance liquid chromatography (HPLC) on a C 8 - or C 18
30、 -column and detection by fluorescence (FLD) or mass spectrometry (MS). The identification is based on the retention times of the homologues and of the isomers of each homologue. Another identification point is the pattern/fingerprint of the homologues, and the isomer fingerprint of each homologue i
31、f a C 18 -column is used for HPLC. By the use of MS detection the relative intensities of two diagnostic ions may also be used for the identification (optional). The quantification is based on an internal standard procedure. The internal standard (C 8 -LAS) is taken through the whole analytical proc
32、edure. Depending on the type of matrices from which LAS is extracted, different analytical pathways can be applied. An overview of the analytical procedure for the matrix of interest is shown in Table 2. 5 Interferences 5.1 Interferences from sampling Use sampling containers of materials (preferably
33、 glass or steel) that do not significantly affect the sample during the contact through sampling and storage. Plastic containers may be used if it has been proven that they do not significantly affect the sample. 5.2 Interferences by HPLC-FLD and HPLC-MS The chromatographic analysis can be done on a
34、 C 8 - or a C 18 -reverse phase column, and the choice of column determines the separation obtained. On the C 8 -column (with methanol in mobile phase) the LAS homologues are separated; however, there is no separation of the isomers. On the C 18 -column (with acetonitrile in mobile phase) the homolo
35、gues are separated and there is a partial separation of the isomers of each homologue. This is illustrated by the chromatograms in Annex B. The selectivity of the fluorescence as well as the mass selective detector is high; however, interference from co-eluting substances may occur. It is essential
36、that the interfering peaks not be included in the calculations. A peak is excluded if the retention time differs from the LAS standard mixture. Interfering peaks can best be detected when a C 18 -column is used for the LC analysis, due to the partial separation of the isomers. The C 18 -column is ma
37、ndatory when fluorescence is used, due to the higher selectivity obtained. The interfering peaks can usually be detected by comparing the fingerprints of the sample with the fingerprints of the LAS standard mixture, although the isomer and homologue distribution in the environmental samples may diff
38、er from the distribution in the standard mixture. Th e hi gh est s e l ectivi ty is o b tain ed b y th e us e o f a C 18 -co l umn an d th e MS d etecto r . H o w e v e r , f o r m o st applications, the separation on a C 8 -column is sufficient, when MS is used. When all isomers are eluted in one p
39、eak, the integrations are less complicated, resulting in a higher precision and a lower limit of detection. Table 2 Choice of analytical procedure Matrix FLD MS C 8 -column C 18 -column C 8 -column C 18 -column Sludge No Yes Yes Yes Soil No (Yes) a Yes Yes Treated biowaste No (Yes) a Yes Yes aFor FL
40、D, the limit of detection will generally be inadequate for this type of matrix. 2 ISO 2012 All rights reserved ISO/TS 13896:2012(E) 6 Reagents 6.1 General Use only reagents of recognized analytical grade, unless otherwise specified. The purity of the reagents used shall be checked by running a blank
41、 determination as described in 9.4. 6.2 Methanol, CH 3 OH; HPLC grade. 6.3 Acetonitrile, C 2 H 3 N; HPLC grade. 6.4 Ammonium acetate, c(CH 3 COO -NH 4 + ) = 0,01 mol/l. 6.5 Mobile phases for HPLC 6.5.1 For isomeric separation on C 18 -column Mobile phase A: 0,01 mol/l ammonium acetate (6.4); Mobile
42、phase B: Acetonitrile (6.3). 6.5.2 For homologue separation on C 8 -column Mobile phase A: 0,01 mol/l ammonium acetate (6.4); Mobile phase B: Methanol (6.2). 6.6 Reagents for clean-up procedures 6.6.1 Clean-up procedure based on strong anion exchange (SAX) 6.6.1.1 SAX column 6.6.1.2 Acetic acid, CH
43、3 COOH 6.6.1.3 Hydrochloric acid, HCl 6.6.1.4 Methanol, CH 3 OH 6.6.2 Clean-up procedure based on graphitized carbon black (GCB) 6.6.2.1 GCB column 6.6.2.2 Hydrochloric acid, HCl 6.6.2.3 Tetramethylammonium hydroxide, C 4 H 13 NO (CAS-RN 10424-65-4 1) ) pentahydrate. 6.6.2.4 Formic acid, HCOOH 6.6.2
44、.5 Dichloromethane, CH 2 Cl 2 1) CAS-RN Chemical Abstracts Service Registry Number. ISO 2012 All rights reserved 3 ISO/TS 13896:2012(E) 6.6.2.6 Methanol, CH 3 OH 6.7 Nitrogen, N 2 , for solvent evaporation of sufficient purity. 6.8 Standards for calibration 6.8.1 General The standards shall be store
45、d in a freezer at a temperature of (18 3) C. 6.8.2 C 11 -LAS, sodium linear undecylbenzene sulfonate, C 17 H 27 SO 3 Na; 99 %. 6.8.3 C 12 -LAS, sodium linear dodecylbenzene sulfonate, C 18 H 29 SO 3 Na; 99 % (CAS-RN 2211-98-5). 6.8.4 C 13 -LAS, sodium linear tridecylbenzene sulfonate, C 19 H 31 SO 3
46、 Na; 99 %. 6.8.5 C 10 -C 14 -LAS mixture of homologues and isomers, highest possible purity (CAS-RN 69669-44- 9, CAS-RN 25155-30-0). 6.9 Internal standard, C 8 -LAS Octylbenzene sulfonic acid, sodium salt C 14 H 21 SO 3 Na (CAS-RN 6149-03-7). The internal standard shall be stored in the freezer at a
47、 temperature of (18 3) C. 6.10 Internal standard solution Prepare the internal standard solution of the internal standard (6.9) by dilution to about 1 000 mg/l in methanol (6.2). It is essential that the same internal standard solution be used for calibration standard solutions and for samples, blan
48、k tests and internal quality control samples. Store the internal standard solution in a dark place at a temperature of (4 3) C. The solution is stable for at least two years. 6.11 Stock solutions Prepare individual stock solutions of 1 000 mg/l to 5 000 mg/l in methanol (6.2), either from solid stan
49、dard substances or from solutions with a certified concentration. Prepare stock solutions of C 11 - LAS (6.8.2), C 12 -LAS (6.8.3) and C 13 -LAS (6.8.4). Prepare a calibration mixture by mixing stock solutions of C 11 -LAS, C 12 -LAS and C 13 -LAS containing equal concentrations of each homologue. Prepare a stock solution of C 10to C 14 -LAS mixture (6.8.5) of 1 000 mg/l to 5 000 mg/l in methanol (6.2). This solution is only for identification. Store the stock solutions and the calibration mixt
