CEN/TC 275/WG 3 - Pesticides and PCB's in foods of animal origin

This document specifies a method for the analysis of pesticide residues in foods of plant and of animal origin by ethyl acetate extraction using GC- and LC-MS/MS (SweEt).

This Technical Specification gives guidelines for the execution of calibration and quantitative evaluation of chromatographic procedures for the determination of pesticides and organic contaminants in residue analysis. In addition, the essential requirements for calibration are outlined.
The calibration of analytical procedures and the evaluation of analytical results need to be conducted according to uniform principles in order to allow for a comparison of analytical results (even from different analytical procedures). They constitute the basis of any method validation and of the quality assurance within laboratories [1], [2], [3].
This Technical Specification does not consider issues of identification/qualification and extraction efficiency.

This Technical Specification describes a method for the analysis of pesticide residues in fatty oils of plant origin (essential oils are excluded). It has been validated in an interlaboratory test with olive oil. However, laboratory experiences have shown that this method is also applicable to other kinds of oils such as sunflower seed oil, sesame oil, flax seed oil, rape seed oil, grape seed oil, thistle oil and pumpkin seed oil.

This European Standard stipulates a method for the analysis of pesticide residues in foods of plant origin, such as fruits (including dried fruits), vegetables, cereals and many processed products thereof by using GC, GC-MS(/MS), and/or LC-MS(/MS). The method has been collaboratively studied on a large number of commodity/pesticide combinations. Precision data are summarized in FprCEN/TR 17063. Guidelines for calibration are outlined in FprCEN/TS 17061.

This Technical Report lists the validation data which were obtained with EN 15662:2008 and prEN 15662:2016 in interlaboratory tests and in single laboratory method validation studies.

This Technical Report lists the mass spectrometric parameters which are useful for the application of European Standards for the determination of pesticide residues in foods of plant origin that use GC-MS. These European Standards are as follows:
EN 1528 (all parts), Fatty food - Determination of pesticides and polychlorinated biphenyls (PCBs)
EN 12393 (all parts), Foods of plant origin  - Multiresidue methods for the gas chromatographic determination of pesticide residues
EN 15662, Foods of plant origin  - Determination of pesticide residues using GC-MS and/or LC-MS/MS following acetonitrile extraction/partitioning  - QuEChERS-method
To facilitate the determination of pesticides and/or metabolites using GC-MS/MS, Table 2 specifies the diagnostic ion transitions suitable for identification and quantification, which can be used.

This European Standard gives general considerations for the determination of pesticide residues in foods of plant origin.
Each method specified in this European Standard is suitable for identifying and quantifying a definite range of those organohalogen, and/or organophosphorus and/or organonitrogen pesticides which occur as residues in foodstuffs of plant origin.
This European Standard contains the following methods that have been subjected to interlaboratory studies and/or are adopted throughout Europe:
-   method M: Extraction with acetone and liquid liquid partition with dichloromethane/light petroleum, if necessary clean-up on Florisil® 1) [1], [2], [3];
-   method N: Extraction with acetone, liquid liquid partition with dichloromethane or cyclohexane/ethyl acetate and clean-up with gel permeation and silica gel chromatography [4], [5];
-   method P: Extraction with ethyl acetate and, if necessary, clean-up with gel permeation chromatography [6].
The applicability of the three methods M, N and P for residue analysis of organohalogen, organophosphorus and organonitrogen pesticides, respectively, is given for each method.

This European Standard gives guidance on some recommended techniques for the determination of pesticide residues in foods of plant origin and on confirmatory tests.
The identity of any observed pesticide residue is confirmed, particularly in those cases in which it would appear that the maximum residue limit has been exceeded.

This European Standard specifies methods for the extraction and clean-up of food samples of plant origin for quantitative determination of pesticide residues.
Different solvents can be used for this purpose. These pesticide residues are generally associated with other co-extracted compounds which would interfere in the analysis. To purify the crude extracts to be analysed, several techniques can be used.
This European Standard contains the following extraction and clean-up methods that have been subjected to interlaboratory studies and/or are adopted throughout Europe:
-   method M: Extraction with acetone and liquid-liquid partition with dichloromethane/light petroleum, if necessary clean-up on Florisil®  ) [1], [2], [3];
-   method N: Extraction with acetone, liquid-liquid partition with dichloromethane or cyclohexane/ethyl acetate and clean-up with gel permeation and silica gel chromatography [4], [5];
-   method P: Extraction with ethyl acetate, and if necessary, clean-up by gel permeation chromatography [6].
This European Standard specifies the details of methods M, N and P for the extraction and the clean-up of food samples of plant origin. Several solvents at different volumes are used for extraction. Techniques of clean-up are listed such as liquid-liquid partition, liquid chromatography on various adsorbents and gel permeation chromatography.
A table providing the couples (matrix/pesticide) which have been submitted to collaborative studies and a list of indicative applicability of the method to different pesticides are given for each method, wherever possible.

This Technical Report lists mass spectrometric parameters which are useful for the application of European Standards for the determination of pesticide residues in foods that use GC-MS, such as the following standards:
-   EN 1528 (all parts), Fatty food - Determination of pesticides and polychlorinated biphenyls (PCBs);
-   EN 12393 (all parts), Foods of plant origin - Multiresidue methods for the gas chromatographic determination of pesticide residues;
-   EN 15662, Foods of plant origin - Determination of pesticide residues using GC-MS and/or LC-MS/MS following acetonitrile extraction/partitioning and clean-up by dispersive SPE - QuEChERS-method.
To facilitate the determination of pesticides and/or metabolites using GC-MS, Table 1 specifies the diagnostic ions suitable for quantification, which can be used.

This European Standard describes a method for the analysis of pesticide residues in foods 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.

This Technical Report lists mass spectrometric parameters which are useful for the application of European Standards for the determination of pesticide residues in foods of plant origin that use LC-MS/MS, such as the standards in preparation:
prEN 15637 "Foods of plant origin — Determination of pesticide residues using LC-MS/MS following methanol extraction and clean up using diatomaceous earth"
prEN 15662 "Foods of plant origin — Determination of pesticide residues using GC-MS and/or LC-MS/MS following acetonitrile extraction/partitioning by dispersive SPE — QuEChERS-method”
To facilitate the determination of active substances and/or metabolites using LC-MS/MS, Table 1 specifies the precursor ions and product ions suitable for quantification, which can be used independently of the type of triple quadrupole mass spectrometer. However, using an ion trap mass spectrometer other product ions can be generated or at least the relative intensities of the ions are different to triple quadrupole instruments. Furthermore, the additional parameters declustering potential (DP), collision energy (CE), relative retention times and an approximate classification of detection sensitivity are presented in Table 1. These were derived using the API 2000 ) and should be applicable at least for other instruments of the API type (Applied Biosystems).

This draft European Standard specifies a method using high performance liquid chromatography/mass spectrometry (LC-MS) for the determination of the growth regulators chlormequat and mepiquat in non fatty foods as chlormequat and mepiquat cation, respectively.
The method is applicable to all kinds of fruits, vegetables and cereal products. It has been collaboratively studied on mushrooms, pears, wheat flour and fruit puree, see [1].

This draft European Standard specifies a method using high performance liquid chromatography/tandem mass spectrometry (LC-MS/MS) for the determination of the growth regulators chlormequat and mepiquat in non-fatty foods as chlormequat and mepiquat cation, respectively.
The method is applicable to all kinds of fruits, vegetables and cereal products. It has been collaboratively studied on mushrooms, pears, wheat flour, fruit puree and, additionally, on infant formula, see [1].

This European Standard specifies a gas chromatographic (GC) method for the determination of bromide residues (including some organic bromine present) as inorganic bromide in non-fatty foods. Generally, the maximum residue levels are expressed in terms of bromide ion from all sources but not including covalently bound bromine. The method is applicable to beets, carrots, chicory, endives, cereal grains, lettuce, potatoes, spinach, strawberries and tomato. It has been validated in an interlaboratory test on lettuce (1).

This European Standard specifies a gas chromatographic method for the determination of inorganic bromide residues in non-fatty foods. Generally, the maximum residue levels are expressed in terms of bromide ion from all sources but not including covalently bound bromine. The method is applicable to cereals, dried fruit, dried vegetables, dried mushrooms, fresh fruit and vegetables. It has been validated in an interlaboratory study on maize flour, carrot flakes, lettuce, potatoes, cereal flour and hazelnuts (1), (2).

This European Standard specifies a UV spectrometric method for the determination of low-level residues of dithiocarbamate and thiuram disulfide fungicides as xanthogenate. Dithiocarbamate and thiuram disulfide fungicides release carbon disulfide under specified conditions (e.g. mancozeb, maneb, propineb, thiram, zineb). It is applicable to such compounds especially in and on those foodstuffs of plant origin for which low maximum residue levels have been set.

This European Standard specifies a spectrometric method for the determination of residues of dithiocarbamates and thiuram disulfides, which release carbon disulfide under the described conditions (e.g. mancozeb, maneb, propineb, thiram, zineb). It is applicable to such compounds in and on fruits and many vegetables  and also in and on cereals and other foodstuffs of plant origin. Only the quantification of the whole group is possible using this method but not the identification of individual compounds.

This European standard specifies a gas chromatographic method for the determination of residues of dithiocarbamates and thiuram disulfides, which release carbondisulfide under the described conditions (e.g. mancozeb, maneb, propineb, thiram, zineb). It is applicable to such compounds in and on fruits and some vegetables but also in and on cereals and other foodstuffs of plant origin. Only the quantification of the whole group is possible using this method not the identification of individual compounds.

This part of prEN 1528 specifies a range of analytical procedures for extractingthe fat portion containing the pesticide and PCB residues from different groups of fat-containing foodstuffs.

This part of prEN 1528:1994 specifies some recommended techniques for the determination of pesticides and PCBs in fatty foodstuffs, confirmation of results and an additional clean-up procedure.

This part of EN 1528 specifies the details of methods A to H for the clean-up of fats and oils or the isolated fat portion, respectively, using techniques such as liquid/liquid partition, adsorption or gel permeation column chromatography. The applicable usage of the methods A to H is given in detail ineach method described. Note: See also prEN 1528-4 which lists a clean-up procedure for the removal of the bulk of lipids when analysing large quantities of fat.

This draft European Standard specifies methods of quantitative determination of residues of pesticides and PCBs in fatty food. Each method described in this draft European Standard is suitable for identifying and quantifying a definite range of those non-polar organochlorine and/or organophosphorus pesticides whichoccur as residues in fats and oils as well as in the fat portion of fat- containing foodstuffs, both of either animal or vegetable origin.

This document specifies a method for the analysis of pesticide residues in foods of animal origin with a fat content of up to approximatively 10 %, such as meat, egg or milk by LC-MS/MS. Because of the low material requirements for miniaturized processing and the few work steps, the process is particularly time and cost-saving with high reliability and effectiveness. The method has been collaboratively studied on a number of commodity/pesticide combinations. Precision data are summarized in Table B.1. Guidelines for calibration are outlined in CEN/TS 17061.

This document specifies a procedure for the analysis of residues of highly polar pesticides and metabolites, which are not amenable to common multiresidue methods, in various food commodities of plant and animal origin, including fruits, vegetables, cereals, pulses, oily seeds, nuts, milk, liver and honey. The method was developed at the EURL-SRM hosted at CVUA Stuttgart and has been collaboratively studied on a large number of commodity/pesticide combinations. Guidelines for calibration are outlined in CEN/TS 17061:2019.

This draft European Standard specifies a high performance liquid chromatographic (HPLC) method for the determination of residues of N-methylcarbamate pesticides in fruits and vegetables and is based on the method of Krause [1].
The method has been validated by collaborative study for aldicarb, carbofuran, furathiocarb, methomyl, oxamyl, propoxur and thiodicarb parent compounds and for the metabolites aldicarb sulfoxide, aldicarb sulfone (aldoxycarb) and 3-hydroxy-carbofuran in tomatoes and oranges at levels between 0,04 mg/kg and 0,25 mg/kg.
No collaborative data are available for the performance of the method in the determination of other significant compounds although it is known that the method is unsatisfactory for benfuracarb.

This En describes a method for the determination of N-methyl-carbamate residues in foodstuffs.

This Technical Specification describes the execution of calibration and quantitative evaluation of chromatographic procedures for the determination of pesticides and organic contaminants in residue analysis. In addition, the essential requirements for calibration are outlined.
The calibration of analytical procedures and the evaluation of analytical results need to be conducted according to uniform principles in order to allow for a comparison of analytical results (even from different analytical procedures). They constitute the basis of any method validation and of the quality assurance within laboratories [1], [2], [3].
This Technical Specification does not consider issues of identification/qualification and extraction efficiency.

This European Technical Specification describes a method for the analysis of pesticide residues in plant oils (fat content > 90 %, water content < 5 %). It has been validated in an interlaboratory test with olive oil. However, laboratory experiences are available also for other kind of oils such as sunflower seed oil, sesame oil, flax seed oil, rape seed oil, grape seed oil, thistle oil and pumpkin seed oil.

This European Standard describes a method for the analysis of pesticide residues in foods of plant origin, such as fruits (including dried fruits), vegetables, cereals and processed products thereof. The method has been collaboratively studied on a large number of commodity/pesticide combinations.