1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN 1528-2 : 1997 The E
2、uropean Standard EN 1528-2 : 1996 has the status of a British Standard ICS 67.040 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Fatty food Determination of pesticides and polychlorinated biphenyls (PCBs) Part 2. Extraction of fat, pesticides and PCBs, and determination of fa
3、t contentBS EN 1528-2 : 1997 This British Standard, having been prepared under the direction of the Consumer Products and Services Sector Board, was published under the authority of the Standards Board and comes into effect on 15 June 1997 BSI 1997 The following BSI references relate to the work on
4、this standard: Committee reference AW/-/3 Draft for comment 94/505375 DC ISBN 0 580 27380 6 Amendments issued since publication Amd. No. Date Text affected Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Panel AW/-/3, Food analysis
5、 Horizontal methods, upon which the following bodies were represented: Association of Public Analysts Department of Trade and Industry (Laboratory of the Government Chemist) Food and Drink Federation Institute of Food Science and Technology Ministry of Agriculture Fisheries and Food Royal Society of
6、 ChemistryBS EN 1528-2 : 1997 BSI 1997 i Contents Page Committees responsible Inside front cover National foreword ii Foreword 2 Text of EN 1528-2 3ii BSI 1997 BS EN 1528-2 : 1997 National foreword This British Standard has been prepared by Technical Committee AW/-/3 and is the English language vers
7、ion of EN 1528-2 : 1996 Fatty food Determination of pesticides and polychlorinated biphenyls (PCBs) Part 2 : Extraction of fat, pesticides and PCBs, and determination of fat content published by the European Committee for Standardization (CEN). EN 1528-2 was produced as a result of international dis
8、cussions in which the United Kingdom took an active part. Cross-references Publication referred to Corresponding British Standard EN 1528-1 : 1996 BS EN 1528-1 : 1997 Fatty food Determination of pesticides and polychlorinated biphenyls (PCBs) Part 1 : General EN 1528-3 : 1996 BS EN 1528-3 : 1997 Fat
9、ty food Determination of pesticides and polychlorinated biphenyls (PCBs) Part 3 : Clean-up methods EN 1528-4 : 1996 BS EN 1528-4 : 1997 Fatty food Determination of pesticides and polychlorinated biphenyls (PCBs) Part 4 : Determination, confirmatory tests, miscellaneous Compliance with a British Stan
10、dard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the EN title page, pages 2 to 8, an inside back cover and a back cover.CEN European Committee for Standardization Comite Europe en de Normali
11、sation Europa isches Komitee fu r Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1996 Copyright reserved to CEN members Ref. No. EN 1528-2 : 1996 E EUROPEAN STANDARD EN 1528-2 NORME EUROPE ENNE EUROPA ISCHE NORM November 1996 ICS 67.040 Descriptors: Food products, edible fats, chem
12、ical analysis, determination of content, pesticides, polychlorobiphenyl, fats, extraction English version Fatty food Determination of pesticides and polychlorinated biphenyls (PCBs) Part 2 : Extraction of fat, pesticides and PCBs, and determination of fat content Aliments gras Dosage des pesticides
13、et des polychlorobiphe nyles (PCB) Partie 2 : Extraction de la matie re grasse, des pesticides et des PCB, et de termination de la teneur en matie re grasse Fettreiche Lebensmittel Bestimmung von Pestiziden und polychlorierten Biphenylen (PCB) Teil 2 : Extraktion des Fettes, der Pestizide und PCB un
14、d Bestimmung des Fettgehaltes This European Standard was approved by CEN on 1996-10-27. 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 list
15、s and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat 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 respon
16、sibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway,
17、 Portugal, Spain, Sweden, Switzerland and United Kingdom.Page 2 EN 1528-2 : 1996 BSI 1997 Foreword This European Standard has been prepared by Technical Committee CEN/TC 275, Food analysis, horizontal methods, the secretariat of which is held by DIN. This European Standard shall be given the status
18、of a national standard, either by publication of an identical text or by endorsement, at the latest by May 1997, and conflicting national standards shall be withdrawn at the latest by May 1997. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following c
19、ountries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. This European Standard consists of the following Parts. Part 1 G
20、eneral presents the scope of the standard and describes general considerations with regard to reagents, apparatus, gas chromatography etc., applying to each of the analytical methods selected. Part 2 Extraction of fat, pesticides and PCBs, and determination of fat content presents a range of analyti
21、cal procedures for extracting the fat portion containing the pesticide and PCB residues from different groups of fat-containing foodstuffs. Part 3 Clean-up methods presents the details of methods A to H for the clean-up of fats and oils or the isolated fat portion, respectively, using techniques suc
22、h as liquidliquid partition, adsorption or gel permeation column chromatography. Part 4 Determination, confirmatory tests, miscellaneous gives guidance on some recommended techniques for the determination of pesticides and PCBs in fatty foodstuffs and on confirmatory tests, and lists a clean-up proc
23、edure for the removal of the bulk of lipids when analysing large quantities of fat. Contents Page Foreword 2 Introduction 3 1 Scope 3 2 Normative references 3 3 Principle 3 4 Reagents and materials 3 5 Apparatus 4 6 Procedures 4 7 Further processing 7 8 Evaluation of results 7 9 Test report 7 Annexe
24、s A (informative) Purification of some solvents and reagents 8 B (informative) Bibliography 8Page 3 EN 1528-2 : 1996 BSI 1997 1) IU (often called the International Unit or standard unit) is defined as the amount of enzyme which will catalyse the transformation of 1mmol substrate per minute under sta
25、ndard conditions. 2) Celite 545 is an example of a suitable product available commercially. 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. Introduction This European Standard comprises a range of mu
26、lti-residue methods of equal status: no single method can be identified as the prime method because, in this field, methods are continuously developing. The methods selected for inclusion in this standard have been validated and are widely used throughout Europe. Any variation in the methods used sh
27、ould be shown to give comparable results. The residues to be analysed in this European Standard are associated with the fat portion of the samples. In many cases, the residues are expressed in milligrams of pesticide per kilogram of fat (see clause 11 of EN 1528-1 : 1996). In such cases, it is not n
28、ecessary to determine the fat content of the product, but to measure the residues in a known mass of extracted fat. With all other products, residue levels are reported on a whole product basis and therefore it is necessary to determine the percentage of fat in the product. 1 Scope This Part of EN 1
29、528 specifies a range of analytical procedures for extracting the fat portion containing the pesticide and polychlorinated biphenyl (PCB) residues from different groups of fat-containing foodstuffs. 2 Normative references This European Standard incorporates by dated or undated reference, provisions
30、from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amen
31、dment or revision. For undated references the latest edition of the publication referred to applies. EN 1528-1:1996 Fatty food Determination of pesticides and polychlorinated biphenyls (PCBs) Part 1 : General EN 1528-3:1996 Fatty food Determination of pesticides and polychlorinated biphenyls (PCBs)
32、Part 3 : Clean-up methods EN 1528-4:1996 Fatty food Determination of pesticides and polychlorinated biphenyls (PCBs) Part 4 : Determination, confirmatory tests, miscellaneous 3 Principle Extraction of the residues from the sample matrix by the use of appropriate solvents, so as to obtain the maximum
33、 efficiency of extraction of the residue and minimum co-extraction of any substances which can give rise to interferences in the determination. Removal of the solvents by evaporation and, optionally, determination of the fat content by weighing out the mass of the remainder. 4 Reagents and materials
34、 All reagents and materials used shall be suitable for the analysis of residues of pesticides and PCBs and shall be in accordance with 4 in EN 1528-1 : 1996. If purification is necessary, the procedures given in annex A are appropriate. 4.1 Acetone. 4.2 Acetonitrile. 4.3 Diethyl ether, peroxide free
35、. 4.4 Dichloromethane. 4.5 Extraction mixture, acetonitrile (4.2) + dichloromethane (4.4)7 5:2 5( V/V). 4.6 Light petroleum, having a boiling range from 40 C to 60 C. 4.7 Methanol or ethanol. 4.8 n-hexane. 4.9 Enzyme suspension, phospholipase C suspension, 800 IU/ml 1) , in ammonium sulfate solution
36、 (3,2 mol/l). Store at 1 C to 4 C (do not freeze). 4.10 Glycine buffer solution, 0,2 mol/l of glycine containing 0,1 g/l of zinc sulfate. 4.11 Sodium sulfate solution, 2 g/100 ml. 4.12 Sodium chloride solution, saturated. 4.13 Sodium oxalate, or potassium oxalate. 4.14 Sodium sulfate, granular, anhy
37、drous. Before use, heat at 500 C or 550 C for at least 4 h and then allow to cool in a desiccator. 4.15 Filter aid, for example Celite 545 2) . Before use, heat at 400 C for at least 4 h, allow to cool in a desiccator and store in an airtight bottle. 4.16 Sea sand, acid washed. Before use, heat at 4
38、00 C for at least 4 h and allow to cool in a desiccator.Page 4 EN 1528-2 : 1996 BSI 1997 5 Apparatus Usual laboratory equipment and, in particular, the following. 5.1 Analytical balance, suitable for weighings in the range 0,01 g up to 1000 g. 5.2 Analytical balance, suitable for weighings in the ra
39、nge 0,1 mg up to 1 g. 5.3 Centrifuge, explosion proof, provided with glass tubes of capacity 200 ml up to 500 ml, in which the tubes can be spun at a rotational frequency of 1000 min 21 to 2000 min 21 . 5.4 Refrigerated centrifuge, explosion proof, cooled to 215 C, provided with centrifuge tubes of
40、capacity 50 ml up to 300 ml, in which the tubes can be spun at a rotational frequency of 1000 min 21 up to 3000 min 21 . 5.5 Device, for mincing foodstuffs of animal origin (food chopper). 5.6 High speed blender, fitted with a leak proof glass jar and an explosion proof motor, or homogenizer. 5.7 Vo
41、rtex, or test tube mixing apparatus. 5.8 Drying oven, capable of being controlled between ambient temperature and 250 C. 5.9 Muffle furnace, capable of being controlled between 400 C and 600 C. 5.10 Microwave oven (optional). 5.11 Refrigerator, spark proof, for storage of sample extracts. 5.12 Rotar
42、y evaporator, with evaporation flasks of capacity 500 ml and a water bath capable of being controlled between 20 C and 50 C. 5.13 Soxhlet extraction apparatus, comprising: a) round-bottomed flask, of capacity 500 ml; b) extraction chamber, of capacity approximately 200 ml; c) reflux condenser; d) he
43、at source (for example a heating mantle). 5.14 Sand or water bath, capable of being controlled between ambient temperature and 100 C. 5.15 Borosilicate bottles, 250 ml, glass. 5.16 Extraction tube, comprising a glass tube of internal diameter 12 mm and of length 300 mm, having a capillary exit below
44、, and at the upper end a section of length 100 mm of internal diameter 50 mm. 5.17 Extraction thimbles (optional). The use of extraction thimbles can often result in the presence of impurities in the sample extracts (interference peaks in the gas chromatogram). They should therefore be pre-extracted
45、 with solvent of the highest purity and stored in an all-glass container. 5.18 Separating funnels, of capacity 500 ml and 1000 ml. 5.19 Sintered glass funnels, of capacity 80 ml, disk diameter 4 cm. 5.20 Volumetric flasks, of suitable capacity, e.g. 5 ml, 10 ml. 5.21 Cotton wool and glass wool, chem
46、ically pure. Before use, extract with n-hexane/acetone and store in a well-stoppered flask. 5.22 Filter paper, round, of diameter approximately 30 cm, sufficiently solvent washed. 5.23 Mortar and pestle. 6 Procedures 6.1 Milk 6.1.1 AOAC extraction 1, 2 To 100 ml of fluid milk in a 500 ml centrifuge
47、tube (5.3), add 100 ml of ethanol or methanol (4.7) and 1 g of sodium oxalate or potassium oxalate (4.13) and mix. Add 50 ml of diethyl ether (4.3) and shake vigorously for 1 min. Add 50 ml of light petroleum (4.6) and shake vigorously for 1 min. Centrifuge for about 5 min at about 1500 min 21 . Blo
48、w off the solvent layer into a 1 l separating funnel containing 500 ml to 600 ml of water and 30 ml of saturated sodium chloride solution (4.12). Re-extract the residue twice, shaking vigorously with 50 ml portions of diethyl ether/light petroleum 1 : 1 (V/V). Centrifuge and blow off the solvent lay
49、er into the separating funnel after each extraction. Mix the combined extracts and water cautiously. Drain and discard the water layer. Rewash the solvent layer twice with 100 ml portions of water, discarding the water each time. (If emulsions form, add about 5 ml of saturated sodium chloride solution to the solvent layer or include with the water wash.) Pass the solvent solution through a column of anhydrous sodium sulfate (4.14), 50 mm 3 25 mm outer diameter, and collect the eluate in a 400 m
