《BS-EN-15637-2008.pdf》由会员分享，可在线阅读，更多相关《BS-EN-15637-2008.pdf（66页珍藏版）》请在三一文库上搜索。
1、BS EN 15637:2008 ICS 67.050 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BRITISH STANDARD Foods of plant origin Determination of pesticide residues using LC-MS/MS following methanol extraction and clean- up using diatomaceous earth Licensed Copy: London South Bank Universit
2、y, South Bank University, 31/01/2009 03:22, Uncontrolled Copy, (c) BSI This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 November 2008 BSI 2008 ISBN 978 0 580 58242 4 Amendments/corrigenda issued since publication DateComments BS EN 15637:20
3、08 National foreword This British Standard is the UK implementation of EN 15637:2008. The UK participation in its preparation was entrusted to Technical Committee AW/-/3, Food analysis - Horizontal methods. A list of organizations represented on this committee can be obtained on request to its secre
4、tary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. Licensed Copy: London South Bank University, South Bank University, 31/0
5、1/2009 03:22, Uncontrolled Copy, (c) BSI BS EN 15637:2008 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 15637 November 2008 ICS 67.050 English Version Foods of plant origin - Determination of pesticide residues using LC-MS/MS following methanol extraction and clean-up using diatomaceous earth
6、 Aliments dorigine vgtale - Dtermination des rsidus des pesticides par LC-MS/MS aprs extraction mthanolique et purification sur terre de diatomes Pflanzliche Lebensmittel - LC-MS/MS-Verfahren zur Bestimmung von Pestizidrckstnden mit Methanolextraktion und Reinigung an Diatomeenerde This European Sta
7、ndard was approved by CEN on 13 September 2008. 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 concern
8、ing such national standards may be obtained on application to the CEN 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
9、language and notified to the CEN Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuani
10、a, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2008 CE
11、NAll rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 15637:2008: E Licensed Copy: London South Bank University, South Bank University, 31/01/2009 03:22, Uncontrolled Copy, (c) BSI BS EN 15637:2008 EN 15637:2008 (E) 2 Contents Page Foreword
12、3 1 Scope 4 2 Principle4 3 Reagents.4 4 Apparatus .6 5 Procedure .7 6 Evaluation of results .12 7 Confirmatory tests.16 8 Precision.16 9 Test report16 Annex A (informative) Example for appropriate experimental conditions17 Annex B (informative) Precision data21 Bibliography63 Licensed Copy: London S
13、outh Bank University, South Bank University, 31/01/2009 03:22, Uncontrolled Copy, (c) BSI BS EN 15637:2008 EN 15637:2008 (E) 3 Foreword This document (EN 15637:2008) has been prepared by Technical Committee CEN/TC 275 “Food analysis - Horizontal methods”, the secretariat of which is held by DIN. Thi
14、s 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 May 2009, and conflicting national standards shall be withdrawn at the latest by May 2009. Attention is drawn to the possibility that some of the eleme
15、nts 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. WARNING The application of this standard may involve hazardous materials, operations and equipment. It does not claim to address all safety issues
16、 associated with its use. The user of this standard is responsible for establishing appropriate safety and health practices and determining the applicability of regulatory limitations prior to use. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the followi
17、ng countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Sloven
18、ia, Spain, Sweden, Switzerland and the United Kingdom. Licensed Copy: London South Bank University, South Bank University, 31/01/2009 03:22, Uncontrolled Copy, (c) BSI BS EN 15637:2008 EN 15637:2008 (E) 4 1 Scope This European Standard describes a method for the analysis of pesticide residues in foo
19、ds of plant origin, such as fruits, vegetables, cereals, nuts as well as processed products including dried fruits. The method has been collaboratively studied on a large number of commodity/pesticide combinations. 2 Principle The sample is extracted with methanol after addition of some water. After
20、 partition into dichloromethane the organic phase is evaporated and the residue is reconstituted with methanol. Quantification of pesticide residues is performed by liquid chromatography with tandem mass spectrometric detection, using electrospray ionisation. To achieve the required selectivity the
21、mass spectrometer is operated in the selected reaction monitoring mode (SRM). 3 Reagents 3.1 General and safety considerations Unless otherwise specified, use reagents of recognised analytical grade. Take every precaution to avoid possible contamination of water, solvents, inorganic salts, etc. 3.2
22、Ammonium formate 3.3 Sodium chloride 3.4 Water, HPLC quality 3.5 Dichloromethane, for residue analysis 3.6 Methanol, HPLC quality 3.7 Internal Standard (ISTD) solutions in methanol, = 10 g/ml to 50 g/ml1) Table 1 shows a list of potential internal standards that may be used in this method. The conce
23、ntrations listed refer to the ISTD solutions that should be added at the first extraction step (5.2) and to standard solutions. Table 1: Potential internal standards (ISTDs) or quality control (QC) standards Name of the compound Log P (octanol-water partion coefficient) Chlorine atoms Concentration
24、C ISTD g/ml Triphenyl phosphate 4,59 - 20 Tris-(1,3-dichlorisopropyl)- phosphate 3,65 6 50 Bis-nitrophenyl urea (nicarbazin) 3,76 - 10 1) = mass concentration Licensed Copy: London South Bank University, South Bank University, 31/01/2009 03:22, Uncontrolled Copy, (c) BSI BS EN 15637:2008 EN 15637:20
25、08 (E) 5 3.8 Pesticide stock solutions Prepare individual stock solutions of analytical standards at concentrations that are sufficiently high to allow the preparation of complex pesticide mixtures. The solvent used should not negatively influence the stability of the pesticides employed. NOTE Usual
26、ly, store stock solutions at -18 C. Check the stability of stock solutions during storage regularly. In some cases the addition of acids or bases can be helpful to enhance stability and extend the acceptable storage period. 3.9 Pesticide mixtures Because of the broad applicability of this method and
27、 due to the partly divergent pH-stability of pesticides, analyte mixtures of different composition can be needed. These are prepared by mixing together defined volumes of the required analyte stock solutions (3.8) and appropriately diluting them with methanol. The analyte concentrations in this mixt
28、ure should be sufficient to allow the preparation of the required matrix matched standards (see 3.10.3) with moderate dilution of the blank sample extract (e.g. less than 20 %). Usually, store pesticide mixtures at -18 C. Since the stability of the pesticides in the mixture may be lower than in stoc
29、k solutions, stability has to be checked regularly. In some cases the addition of acids or bases can be helpful to enhance stability and extend acceptable storage times. 3.10 Standard solutions 3.10.1 Standard solutions prepared in pure solvent (solvent-based standards) Solvent-based standards are p
30、repared by mixing a certain volume of methanol with known amounts of pesticide mixtures (3.9). The preparation of multiple standards of different pesticide concentration is useful to cover a broad concentration range. NOTE An analyte concentration of 1 g/ml correlates to a residue level of 0,4 mg/kg
31、 when a 10 g sample is employed (e.g. samples with water content 30 %) or 0,8 mg/kg when a 5 g sample is employed (e.g. cereals). 3.10.2 Standard solutions with internal standard prepared in pure solvent Solvent-based standards with ISTD are prepared by mixing a certain volume of methanol with known
32、 amounts of pesticide mixtures (3.9) and a fixed volume of internal standard solution (3.7). The volume used shall result in that concentration of ISTD which is obtained in the final extracts after sample extraction and clean-up (see 5.2 and 5.3). The concentration of internal standard in the final
33、extract (C sample ISTD ) can be calculated using Equation (1). The preparation of multiple standards of different pesticide concentration but with constant ISTD concentration is useful to cover a broad concentration range. endex ISTDISTDsample ISTD VVV VVVCV C = 2 312 )( (1) where: V ISTD is the vol
34、ume of internal standard solution (3.7) added to the test portion; C ISTD is the concentration of internal standard solution (3.7); V1 is the volume of NaCl solution (2,5 ml); V2 is the volume of measuring flask used in 5.2 (10 ml); Licensed Copy: London South Bank University, South Bank University,
35、 31/01/2009 03:22, Uncontrolled Copy, (c) BSI BS EN 15637:2008 EN 15637:2008 (E) 6 V3 is the volume used for solid supported liquid/liquid extraction (5 ml); Vex is the total volume of extraction solvents and natural water (30 ml); Vend is the final volume of extract obtained after clean-up (0,5 ml)
36、. NOTE The internal standard may correct for deviations from the correct extraction volume, a wrong estimate of water content of samples, losses of methanol during preparation of the final extract and fluctuations of instrument sensitivity during a batch of measurements. However, validation results
37、in Annex B were obtained without internal standards. 3.10.3 Standard solutions prepared in blank matrix extracts (matrix-matched standards) Prepare matrix-matched standards in the same way as the solvent-based standards, however, instead of pure methanol use extracts of blank samples (prepared as de
38、scribed in 5.2, but without ISTD addition). To minimize errors caused by matrix induced effects during chromatography, it is best to choose similar commodities (e.g. apple for apple samples, carrots for carrot samples, etc.). The stability of pesticide in matrix-matched standards may be lower than t
39、hat of standards in pure acetonitrile and has to be checked more thoroughly. 3.11 5 ml cartridge for solid supported liquid/liquid extraction, 5 ml sample volume, diatomaceous earth, for example ChemElut CE 10052) 3.12 20 ml cartridge for solid supported liquid/liquid extraction, 20 ml sample volume
40、, diatomaceous earth, for example ChemElut CE 10202) 4 Apparatus Usual laboratory apparatus and, in particular, the following: 4.1 Carving board and knife, for chopping up food samples for analysis 4.2 Homogenizer or high speed blender, fitted with jar 4.3 Laboratory balance 4.4 Measuring flasks, 10
41、 ml and 20 ml 4.5 Ultrasonic bath 4.6 Centrifuge tubes, 80 ml 4.7 Centrifuge, capable of producing a relative centrifugal force (RCF) of at least 3000 g (at the bottom of the tube) 4.8 Round bottom flasks, 50 ml and 250 ml 4.9 Glass syringe, minimum volume 2 ml 2) ChemElut is a product supplied by V
42、arian, Inc. (Palo Alto, CA, USA). This information is given for the convenience of users of this European Standard and does not constitute an endorsement by CEN of the product named. Equivalent products may be used if they can be shown to lead to the same results. Licensed Copy: London South Bank Un
43、iversity, South Bank University, 31/01/2009 03:22, Uncontrolled Copy, (c) BSI BS EN 15637:2008 EN 15637:2008 (E) 7 4.10 Microliter syringes, for sample fortification 4.11 Rotary evaporator, with temperature-controlled water bath 4.12 Syringe filters, 0,45 m pore size, 4 mm diameter, polytetrafluoroe
44、thylene (PTFE) membrane 4.13 Glass vials and caps, 1,8 ml volume, suitable for an autosampler 4.14 LC-MS/MS system, triple quadrupole mass spectrometer with electrospray interface 5 Procedure 5.1 Preparation and storage of the samples 5.1.1 General Sample processing and storage procedures should be
45、demonstrated to have no significant effect on the residues present in the test sample (sometimes also called “analytical sample”). Processing should also ensure that the test sample is homogeneous enough so that sub-sampling variability is acceptable. If a single analytical portion is unlikely to be
46、 representative of the test sample, larger or replicate portions shall be analysed, to provide a better estimate of the true value. The degree of comminution supports a quantitative residue extraction. 5.1.2 Laboratory sample A laboratory sample that is wholly or extensively spoiled or degraded shou
47、ld not be analysed. When possible, prepare laboratory samples immediately after arrival and in any event, before any significant physical or chemical changes have taken place. If a laboratory sample cannot be prepared without delay, it should be stored under appropriate conditions to keep it fresh a
48、nd to avoid deterioration. Generally, laboratory samples should not be stored longer than 3 days before preparation. Dried or similarly processed samples should be analysed within their stated shelf life. 5.1.3 Partly-prepared test sample For preparation of the partly-prepared test sample take only
49、the portion of the laboratory sample to which the maximum residue level applies. No further plant-parts may be removed. The reduction of the laboratory sample shall be carried out in such a way that representative portions are obtained (e. g. by sub-division into four and selection of opposite quarters). For samples of small units (e. g. small fruits such as berries, legumes, cereals), the sample shall be thoroughly mixed before weighing out the partly-prepared test sample. When the samples are made up of larger units, take we