ISO-11369-1997.pdf

INTERNATIONAL STANDARD IS0 11369 First edition 1997-08-01 Water quality - Determination of selected plant treatment agents - Method using high performance liquid chromatography with UV detection after solid-liquid extraction Qua/it6 de I eau - Dosage de certains agents de traitement des p/antes - Mkthode par chromatographie en phase liquide d haute performance (CLHP) avec dktection UV apA extraction solide liquide This material is reproduced from IS0 documents under International Organization for Standardization (ISO) Copyright License number lHSllCCll996. Not for resale. No part of these IS0 documents may be reproduced in any form, electronic retrieval system or otherwise, except as allowed in the copyright law of the country of use, or with the prior written consent of IS0 (Case postale 56,121l Geneva 20, Switzerland, Fax +41 22 734 IO 79), IHS or the IS0 Licenser s members. Reference number IS0 11369:1997(E) Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 01:30:35 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 11369:1997(E) Contents 1 Scope 2 Interferences . 3 Nonnatives references 4 Principle . 5 Reagents . 6 Apparatus 7 Sampling and samples 6 Procedure 9 Calibration . 10 Evaluation 11 Expression of results . 12 Test report . 13 Precision data . Annex A (informative) Recovery rates Annex B (informative) Results of interlaboratory trial Page 1 2 2 2 2 3 4 5 10 13 14 14 14 15 17 0 IS0 1997 All rights reserved. Unless otherwise specified. no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and mkrofilm, without permission in writing from the publisher. International Organization for Standardization Case postale 56 l CH-1211 Geneve 20 9 Switzerland Internet: oentratiso.oh X.400: o=oh; a=400net; p=iso; o=isoos; saxrrtral Printed in Switzerland ii Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 01:30:35 MDTNo reproduction or networking permitted without license from IHS -,-,- Q IS0 IS0 11369:1997(E) Foreword IS0 (the International Organization for Standardization) is a worldwide federation of national standards bodies (IS0 member bodies). The work of preparing International Standards is normally carried out through IS0 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. IS0 collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. 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. International Standard fS0 11369 was prepared by Technical Committee ISO/TC 147, Water A: substituted anilide Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 01:30:35 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 11369:1997(E) IS0 2 Interferences 2.1 Intetferences with the enrichment The commercially available RP (reversed phase)-Cl8 materials are often of varying quality. Considerable batch-to-batch differences regarding quality and selectivity of this material even from one manufacturer are possible. The recovery may vary with the concentration. Co-extractants eluted from the sorbent material can affect the blank and the recovery. Therefore the calibration and analysis are performed on exactly the same batch of sorbent. Also any UV-absorbing material occurring in the water which passes through the procedure and has a retention time similar to the standard will interfere. Suspended matter in the water sample may clog the packing. In this case the water sample is filtered through a glass fibre filter prior to the enrichment. 2.2 Interferences with the HPLC measurement Substances which absorb at the wavelengths of detection and have retention times similar to those of the compounds to be investigated will interfere with the determination. This shall especially be taken into account when examining samples other than ground- and drinking water. 3 Normative references The following standards contain provisions which, through reference to this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possiblity of applying the most recent editions of the standards indicated below. Members of IEC and IS0 maintain registers of currently valid International Standards. IS0 5667-l :1980, Water quality - Sampling - Part 1: Guidance on the design of sampling programmes IS0 5667-2 : 1991, Water quality - Sampling - Part 2: Guidance on sampling techniques IS0 5667-3: 1994, Water quality - Sampling - Part 3: Guidance on the preservation and handling of samples IS0 8466-l: 1990, Water quality - Calibration and evaluation of analytical methods and estimation of performance characteristics - Part 1: Statistical evaluation of the linear calibration function. lSO/TR 13530:-l , Water quality - General guidance to analytical quality control for water analysis 4 Principle The plant treatment substances in the water sample are extracted by solid-liquid extraction on RP-Cl8 material (RP = reversed phase), eluted with a solvent and then separated, identified and quantified by high performance liquid chromatography (HPLC) using UV detection. 5 Reagents 5.1 General requirements Water, solvents and reagents shall be of sufficient purity (e.g. residue grade or HPLC grade) as far as available and shall not contain any measurable UV absorbing substances interfering with the compounds of interest. 5.2 Nitrogen, high purity, for drying solvents and, if need be, for concentration by evaporation of the eluates. 5.3 Helium, high purity, for degassing HPLC solvents (see also 6.131 I) To be published. 2 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 01:30:35 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 IS0 11369:1997(E) 5.4 Mineral acid, e. g. phosphoric acid, c(H,PO,) = 1 mol/l. 5.5 Sodium hydroxide solution c(NaOH) = 1 mol/l. 5.6 RP-Cl8 SOrbetIt, for the solid-phase extraction. For quality and selectivity of the material see 2.1. NOTE: Other solid-phase adsorbents may be used, if the performance is comparable to this material and if it has been proved suitable according to 2.1. 5.7 Solvents, e. g. methanol (CH,OH), acetonitrile KH,CN), acetone (C,H,O). WARNING These solvents, especially acetonitrile, are toxic agents. Caution shall be exercised when handling. 5.8 Reference standards (see table lj, of high purity or certified material. 5.9 Solutions of the individual standards Place 50 mg (for example) of the reference standards (see 5.8) into a 100 ml volumetric flask, dissolve it in methanol or another solvent (see 5.7) and make up to volume with the solvent. NOTE: Simazine is only poorly soluble in acetonitrile. Store the solutions at about 4 “C, protected from light. They are stable for at least one month depending on the compound of interest. For longer use, check regularly by comparison with an independent, preferably certified, standard solution. 5.10 Stock solution As an example, pipette 1 ml each of the solution of the individual substances (see 5.9) into a 100 ml volumetric flask, and make up to volume with methanol or another solvent (5.7). Store the solutions at about 4 “C, protected from light. They are stable for at least one month depending on the compound of interest. 5.11 Reference solutions for multipoint calibration Prepare the solutions by an adequate dilution of the stock solution (5.10) or several stock solutions to have at least 5 multicomponent reference solutions, e.g. pi 3 20 to 200 ng/ml. As solvent, use the initial HPLC eluant mixture. Store the reference solutions at about 4 “C, protected from light. They are stable for at least one week. 5.12 Buffer solutions for gradient elution , As an example, aqueous solution of ammonium acetate (CHJZOONH,), or sodium acetate CH,COONa, concen- tration I20 mmol/l. (See also the figures). Filter the solution through a membrane filter, pore size 0,45 pm, before use. NOTE: Due to microbiological activity, the shelf-life of the buffer may be limited. Therefore it should be replaced every second day. 6 Apparatus 6.1 General requirements Equipment or parts of it which may come into contact with the sample or its extract shall be free from residues that could cause unacceptable interference in blanks. It is recommended to use glass, stainless steel or polytetrafluoroethene (PTFE), and, for cartridges, also polypropene. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 01:30:35 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 11369:1997(E) Q IS0 6.2 cCIrhl*S from polypropene or glass, filled with RP-C18, of e.g. internal diameter 9 mm, length 8 cm, or commercially available prefilled cartridges. 6.3 Flat-bottom flasks or bottles for sampling, preferably brown glass, 1000 ml and 2000 ml, stoppered with ground glass stoppers or with PTFE-lined screw caps. 6.4 Graduated cylinders, 10 ml and 1000 ml. 6.5 Glass VeSSdS for the collection and evaporation of the eluates, such as centrifuge tubes, 12 ml, with ground glass stoppers. 6.6 Equipment for eVapOtcrtiOn Of b) degassing assembly, if necessary; c) column thermostat, able to guarantee a constant temperature with less than * 1 “C deviation; dl UV detector, preferably diode-array detector, for the on-line recording of absorption spectra in the range 200 nm to 350 nm, or alternatively, a detector capable of monitoring at least two different wavelengths. e) data processing or integration system. 7 Sampling and samples Use for sampling carefully cleaned, preferably brown, flat-bottom glass flasks (see 6.3). Rinse the flasks with the water to be sampled; treat the ground glass stoppers or the lined caps in the same way. Fill the bottles to the brim with the water to be examined. 4 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 01:30:35 MDTNo reproduction or networking permitted without license from IHS -,-,- Q IS0 IS0 11369:1997(E) Extract plant treatment substances from the water samples as soon as possible after sample collection. To avoid interferences, collect samples as stated below and according to the approriate part of IS0 5667. If storage is unavoidable, keep the water sample at 4 “C in the dark. NOTE: Water samples may be stored at 4 “C and for not longer than 1 week. 8 Procedure 8.1 General requirements It is absolutely essential that tests conducted according to this International Standard are carried out by suitably qualified staff. The same conditions (e.g. amount of adsorbent, type of cartridge, conditioning, sample volume and flow, eluting steps and volumes) shall be used for all samples within one batch, including the procedure recovery samples. It should be investigated whether, and to what extent, particular problems will require the specification of additional marginal conditions. NOTE: Low recovery rates can result from using an insufficient amount of Cl8 sorbent or an insufficient volume of methanol for the conditioning or elution step. Before analysing, these conditions should be checked and optimized in each laboratory. For common recovery rates, see annex A. 8.2 Conditioning of the RP-Cl8 material For a water volume of 1000 ml, place 1,0 g to 2,0 g of RP-Cl8 material (see 5.6) into a cartridge or a glass column ,or use an adequate commercial device. NOTE: For more polar substances, e.g. metabolites, poor recoveries result when using 1 g/l for a one-litre sample. Rinse the RP-Cl8 material in the cartridge or glass columns with five times its bed volume of eluting solvent (see 5.7). Rewash with water (see 5.1) (using five times its volume) and use the moist carrier material for the enrichment. The sorbent shall remain moist. 8.3 Enrichment If necessary, remove suspended matter by filtration through a glass fibre filter and record this in the final report. If filtration is carried out, use spiked samples in order to verify that the recovery is not influenced by this additional step. Measure the water sample to be examined, e. g. 1 000 ml, adjust the pH to 6 to 8 with either mineral acid (see 5.4) or sodium hydroxide solution (see 5.5). Pass the water sample through 1 g of adsorbent at a flowrate of between 3 ml/min to 15 ml/min. If 2 g of adsorbent are used, the flowrate should not exceed 25 ml/min. Regulate the flowrate by adjusting the vacuum or the overpressure, respectively. Dry the sorbent, for example in a stream of nitrogen or air (at teast 45 min of approximately 200 ml/min of nitrogen or air, room temperature). 5 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 01:30:35 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 11369:1997(E) 0 IS0 8.4 Elution Elute in the following way with at least 1 ml of solvent (see 5.7) per 500 mg of RP-Cl8 material (see 5.6). Place half of the appropriate quantity of eluant onto the column or cartridge, and elute into a glass vessel with conical bottom. Add, after about 15 min, the rest of the eluant and collect the eluate in the same glass vessel. Transfer the residual solvent remaining on the sorbent, by means of vacuum or overpressure, into the receiving vessel. Carefully concentrate the eluate by evaporation, for example in a nitrogen stream at about 35 “C, or with a rotary evaporator under reduced pressure at 30 “C, or alternatively evaporate just to dryne