EN 12393-2:2008

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Pflanzliche Lebensmittel - Multiverfahren zur gaschromatographischen Bestimmung von Pestizidrückständen - Teil 2: Verfahren zur Extraktion und ReinigungAliments d'origine végétale - Méthodes multirésidus de détermination par chromatographie en phase gazeuse de résidus de pesticides - Partie 2: Méthodes d'extraction et de purificationFoods of plant origin - Multiresidue methods for the gas chromatographic determination of pesticide residues - Part 2: Methods for extraction and cleanup67.080.01Sadje, zelenjava in njuni proizvodi na splošnoFruits, vegetables and derived products in general67.050Splošne preskusne in analizne metode za živilske proizvodeGeneral methods of tests and analysis for food productsICS:Ta slovenski standard je istoveten z:EN 12393-2:2008SIST EN 12393-2:2009en,fr,de01-februar-2009SIST EN 12393-2:2009SLOVENSKI
STANDARDSIST EN 12393-2:19991DGRPHãþD

EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 12393-2November 2008ICS 67.080.01Supersedes EN 12393-2:1998
English VersionFoods of plant origin - Multiresidue methods for the gaschromatographic determination of pesticide residues - Part 2:Methods for extraction and cleanupAliments d'origine végétale - Méthodes multirésidus dedétermination par chromatographie en phase gazeuse derésidus de pesticides - Partie 2: Méthodes d'extraction etde purificationPflanzliche Lebensmittel - Multiverfahren zurgaschromatographischen Bestimmung vonPestizidrückständen - Teil 2: Verfahren zur Extraktion undReinigungThis European Standard 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 EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards 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 translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial 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, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2008 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 12393-2:2008: ESIST EN 12393-2:2009

Average water content of crops and foods.37 Bibliography.38
- Part 2 "Methods for extraction and clean-up" presents methods L to P for the extraction and clean-up using techniques such as liquid-liquid partition, adsorption column chromatography or gel permeation column chromatography, etc.
- Part 3 "Determination and confirmatory tests" gives some recommended techniques for the qualitative and the quantitative measurements of residues and the confirmation of the results.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following 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, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. SIST EN 12393-2:2009

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 standard contains the following extraction and clean-up methods that have been subjected to interlaboratory studies and /or are adopted throughout Europe:  method L: Extraction with acetone, liquid-liquid partition with dichloromethane and clean-up on a silica gel/charcoal column [1];  method M: Extraction with acetone and liquid-liquid partition with dichloromethane/light petroleum, if necessary clean-up on Florisil® 1) [2], [3], [4];  method N: Extraction with acetone, liquid-liquid partition with dichloromethane or cyclohexane/ethyl acetate and clean-up with gel permeation and silica gel chromatography [5], [6];  method P: Extraction with ethyl acetate, and if necessary, clean-up by gel permeation chromatography [7]. This European Standard specifies the details of methods L to 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. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 12393-1:2008, Foods of plant origin – Multiresidue methods for the gas chromatographic determination of pesticide residues – Part 1: General considerations EN 12393-3, Foods of plant origin – Multiresidue methods for the gas chromatographic determination of pesticide residues – Part 3: Determination and confirmatory tests 3 Principles As already described in the introduction, in certain occasions it is possible to improve the method performance by variations in equipment used, extraction, clean-up and chromatographic conditions. Such variations shall be always clearly documented and demonstrated to give valid results.
1) Florisil® is an example of a suitable product available commercially. This information is given for convenience of users of this standard and does not constitute an endorsement by CEN of this product. SIST EN 12393-2:2009

(M S) g (V S) ml M S / V S g/ml L 100 Acetone: 200 ½
M 100 Acetone: 200 ½
N
100 a Acetone: 200 ½
P 50 Ethyl acetate: 100 ½
a Only relevant if the water content of the matrix is greater than 70 %. 4.2 Clean-up 4.2.1 Liquid-liquid partition The liquid-liquid partition procedures are summarized in Table 2. Table 2 —Liquid-liquid partition Methods Aliquot portion of extract Volume of added water Volume of solvent Ratio
(A E) ml (V W) ml (V S) ml A E / V W L 50 (= 20 %) 250 50 1/5 M 80 0 200 - a N 200 x a 100 - a a Depends on the water content of the matrix. Two techniques of liquid-liquid partition are proposed:  with added water (methods L, N);  no added water (method M).
4.2.2 Adsorption column chromatography Methods: L, M, N with different adsorbents: silica gel, charcoal, Florisil®, used pure or in mixture. SIST EN 12393-2:2009

Heat at 500 °C for at least 4 h, allow to cool and store in a stoppered bottle. 5.2.9 Activated charcoal 5.2.10 Silica gel 60 for column chromatography, 63 µm to 200 µm (70 mesh to 230 mesh) 5.2.11 Celite® 5453) (optional) 5.3 Apparatus Usual laboratory equipment in accordance with EN 12393-1 and, in particular, the following:
2) BioBeads® S-X 3 is an example of a suitable product available commercially. This information is given for convenience of users of this standard and does not constitute an endorsement by CEN of this product. 3) Celite® 545 is an example of a suitable product available commercially. This information is given for convenience of users of this standard and does not constitute an endorsement by CEN of this product. SIST EN 12393-2:2009

carrot potato savoy cabbage spinach tomato yellow pea bromophos + +
+
bromopropylate
+ +
captan
+
chlorpropham
+
chlorpyrifos
+ +
cypermethrin
+
o, p'-DDE +
p, p'-DDE +
+
o, p'-DDT +
p, p'-DDT +
+
diazinon +
+
+ dichlofluanid +
dicofol
+ +
dieldrin + + + + + + α-endosulfan
+
β-endosulfan
+ +
endosulfan sulfate
+ +
endrin
+
ethion
+
4) For the collaborative studies, the activated charcoal and the silica gel 60, 63 µm to 200 µm (70 mesh to 230 mesh) from the Merck Company were used. This information is given for convenience of users of this standard and does not constitute an endorsement by CEN of these products. SIST EN 12393-2:2009

carrot potato savoy cabbage spinach tomato yellow pea fenarimol
+
fenitrothion +
+
fenpropathrin
+
folpet
+
α-HCH
+
heptachlor epoxide +
+
iprodione
+
lindane (γ-HCH) + + + + + + malathion
+
+ mecarbam
+
parathion +
+ + +
permethrin
+
phosalone +
+
+ pirimiphos-methyl
+
+ + + procymidone
+
propham
+
quintozene
+
+ tetradifon
+
tolclofos-methyl
+
vinclozoline + +
+ +
5.7 Applicability The following pesticides can be analysed by this method: Aldrin Dieldrin Metribuzin Ametryn Dimethachlor Mevinphos Atrazine Dimethoate Naled Azinphos-ethyl Dioxathion Nitrofen Azinphos-methyl Disulfoton Paraoxon Aziprotryne Ditalimfos Parathion Bifenthrin α-Endosulfan Parathion-methyl Bromacil ß-Endosulfan Pendimethalin Bromophos Endosulfan sulfate Permethrin SIST EN 12393-2:2009

Bromopropylate Ethoprophos Phenkapton
Bupirimate Etrimfos Phorate
Captafol Fenamiphos Phosalone
Captan Fenarimol Pirimiphos-methyl Carbophenothion Fenchlorphos Procymidone
Chlorbenside Fenitrothion Profenofos
Chlorfenson Fenpropathrin Profluralin
Chlorfenvinphos Fenson Prometryn
Chlorflurenol Fensulfothion Propazine
Chlorpropham Fenthion Propham Chlorobenzilate Fenvalerate Propyzamide
Chloropropylate Fluchloralin Prothiofos Chlorpyrifos Flucythrinate Pyrazophos
Chlorpyrifos-methyl Fluorodifen Pyrethrins Chlorthal Fluvalinate Quinalphos
Chlorthiophos Folpet Quintozene
Cyanazine Fonofos Simazine
Cyanofenphos Formothion Sulfotep
Cyanophos α-HCH Tecnazene
Cyfluthrin ß-HCH Terbacil
λ-Cyhalothrin Heptachlor Terbufos
Cypermethrin Heptachlor epoxide Terbutryn
p,p'-DDD Heptenophos Tetrachlorvinphos
o,p'-DDE Iodofenphos Tetradifon
p,p'-DDE Iprodione Tetramethrin o,p'-DDT Isofenphos Tetrasul
p,p'-DDT Lindane Thionazin
Desmetryn Malathion Tolylfluanid
Dialifos Mecarbam Triadimefon
Diazinon Metalaxyl Tri-allate Dichlobenil Metazachlor Triazophos
Dichlofenthion Methidathion Trichloronat
Dichlofluanid Methoprotryne Trifluralin
Dichlorvos Methoxychlor Vinclozolin Dicofol Metolachlor
Crops and foods on which the method was tested: Apples Grapes Pineapples Apricots Head cabbage Plums Aubergines Honey Potatoes Beans Kohlrabi Radishes (large and small types) Carrots Leeks Red cabbage Celeriac Lettuce Savoy cabbage Cherries Mandarin oranges Spinach Chillies Mushrooms Strawberries Chinese cabbage Oranges Sweet peppers Corn salad Parsley Tomatoes Cucumbers Peaches Witloof chicory Dandelion Pears
Endives Peas
Heat at 500 °C for at least 4 h, allow to cool, and store in a stoppered bottle. 6.2.5 Dichloromethane 6.2.6 Acetonitrile 6.2.7 Sodium sulfate Heat at 500 °C for at least 4 h, allow to cool, and store in a stoppered bottle. 6.2.8 Florisil® (Floridin or equivalent), 150 µm to 250 µm (60 mesh to 100 mesh) Activate by heating at 130 °C to 135 °C for at least 5 h, allow to cool in a desiccator and transfer to an airtight stoppered jar. The adsorbent thus treated keeps its activity only for 4 days. It can subsequently be reactivated by the same treatment. The activity of the adsorbent should be checked from time to time by eluting pesticide standard materials as described in the method. 6.2.9 Diethyl ether, peroxide-free, containing 2 % (V+V) ethanol 6.2.10 Eluting solvent A: diethyl ether/light petroleum 6+94 (V/V) 6.2.11 Eluting solvent B: diethyl ether/light petroleum 15+85 (V/V) 6.2.12 Eluting solvent C: diethyl ether/light petroleum 50+50 (V/V) 6.2.13 Eluting solvent D: dichloromethane/light petroleum 20+80 (V/V) 6.2.14 Eluting solvent E: dichloromethane/light petroleum/acetonitrile 50+49,65+0,35 (V/V/V) SIST EN 12393-2:2009

Usual laboratory equipment in accordance with EN 12393-1 and, in particular, the following: 6.3.1 High speed blender or homogenizer, with a suitable blender cup 6.3.2 Chromatographic column, with a PTFE stopcock, 22 mm internal diameter, 300 mm long 6.3.3 Solvent evaporator, Kuderna Danish or equivalent 6.4 Procedure 6.4.1 Preparation of the sample Chop finely the test sample and mix carefully to obtain homogeneous test portions. If the water content of the sample is less than 30 %, adjust it to about 80 % by adding water. 6.4.2 Extraction and partition Weigh 100 g (m) of the prepared sample into the blender cup (6.3.1) and add 200 ml of acetone. Blend at high speed for 3 min. Transfer the mixture to a Büchner funnel containing a filter paper moistened with acetone, filter under suction into the Büchner flask and measure the volume of the filtrate. Pour 80 ml of filtrate in a 1 l separating funnel with 100 ml of dichloromethane and 100 ml of light petroleum (6.2.3). Shake for 3 min and leave to separate layers. Transfer the lower aqueous layer to a second 1 l separating funnel. Dry upper organic layer from the first separatory funnel by passing through 3 cm of sodium sulfate (6.2.7) supported on washed glass wool in 10 cm funnel collecting in a round-bottomed flask. Add 7 g of sodium chloride to the aqueous phase and shake for 30 s until sodium chloride (6.2.4) is dissolved. Add 100 ml of dichloromethane and shake for 3 min. Let the layers separate. Transfer the aqueous phase to a third separating funnel and dry the organic phase again on the same sodium sulfate. Add to the third separating funnel 100 ml of dichloromethane and shake for 3 min, separate and discard the aqueous phase and dry the dichloromethane phase on the same layer of sodium sulfate. Wash the sodium sulfate with 50 ml of dichloromethane and concentrate all organic phases to 2 ml. Add 100 ml of light petroleum and again concentrate to 2 ml and again until all dichloromethane disappears. Add 20 ml of acetone and reconcentrate to 2 ml (Vfinal). This concentrate may be injected directly into a gas chromatograph equipped with HECD (Hall detector), NPD or FPD (method M). In some cases, a clean-up is recommended for determination by ECD: methods M1 or M2. For purification, the sample extract is concentrated to 1 ml of acetone (instead of 2 ml) and diluted to a volume of 10 ml with light petroleum. 6.4.3 Clean-up 6.4.3.1 Method M1 Place a plug of cotton wool in the bottom of the chromatographic column (6.3.2) and fill with light petroleum (6.2.3) on 20 cm. Pour 20 g of Florisil® (6.2.8) and tap along the walls of the column to settle the adsorbent. Cover the top of the adsorbent with 1 cm to 2 cm of sodium sulfate (6.2.7). Wash the adsorbent with approximately 30 ml of light petroleum. Place the evaporator flask under the column to receive the eluate. Transfer the extract for purification as described in 6.4.2, to the column, allowing it to pass through at a rate of not more than 5 ml/min. Rinse the container with two 5 ml portions of light petroleum, pouring the rinsings onto SIST EN 12393-2:2009

Wash the adsorbent with approximately 30 ml of light petroleum. Place the evaporator flask under the column to receive the eluate. Transfer the extract for purification as described in 6.4.2 to the column, allowing it to pass through at a rate of not more than 5 ml/min. Rinse the container with two 5 ml portions of light petroleum, pouring the rinsings onto the column, rinse the walls of the chromatographic column with additional small portions of light petroleum and elute at 5 ml/min with 200 ml of eluting solvent D (6.2.13). Elute further with 200 ml of eluting solvent E (6.2.14) into a separate receiver and finally with 200 ml of eluant F (6.2.15). Concentrate each eluate to a suitable definite volume (Vfinal) for examination by GC. 6.5 Gas chromatography and calculations Use a gas chromatographic system suitable for determining organohalogen, organophosphorus and organo-nitrogen pesticide residues. The equivalent sample weight in milligrams per microlitre of final extract solution is calculated according to Equation (1): ρ = final
20080VmWw×−+δ (1) where ρ
is the sample equivalent in milligrams per microlitre; m
is the mass of the test portion, in grams (here: 100 g); W
is the amount of water present in sample, in grams; δw
is the density of water, in milligrams per microlitre; Vfinal
is the volume of final extract solution, in millilitres; 10 ml is the contraction volume. Contraction volume is taken as 10 ml for samples containing 80 g/100 g to 95 g/100 g of water when 200 ml of acetone is used for extraction. Consult reference documents on food composition for average water content. An example of average water content for some crops and vegetables is given in Table A.1. The water content of most fresh fruit and vegetables can be assumed to be 85 g/100 g. NOTE The sample amount in the final extract solution for Florisil® clean-up or GC, can be calculated exactly by measuring the total volume of the original acetone extract. SIST EN 12393-2:2009

7.2 Reagents 7.2.1 General All reagents shall be suitable for the analysis of pesticide residues and in accordance with EN 12393-1:2008, Clause 4. 7.2.2 Acetone 7.2.3 Dichloromethane 7.2.4 Ethyl acetate 7.2.5 Cyclohexane 7.2.6 GPC eluting mixture: cyclohexane/ethyl acetate 1/1 (V+V) 7.2.7 n-Hexane 7.2.8 Isooctane 7.2.9 Toluene 7.2.10 Water, distilled from glass apparatus 7.2.11 Eluant 1: n-hexane / toluene 65+35 (V/V) 7.2.12 Eluant 2: toluene 7.2.13 Eluant 3: toluene / acetone 95+5 (V/V) 7.2.14 Eluant 4: toluene / acetone 80+20 (V/V) 7.2.15 Eluant 5: acetone SIST EN 12393-2:2009

Heat at 500 °C for at least 4 h, allow to cool and store in a stoppered bottle. 7.2.17 Sodium sulfate, powder
Heat at 500 °C for at least 4 h, allow to cool and store in a stoppered bottle. 7.2.18 Salt mixture: sodium sulfate + sodium chloride 1+1 (w/w) 7.2.19 Celite® 545 7.2.20 Silica gel 60 for column chromatography, 63 µm to 200 µm (70 mesh to 230 mesh), deactivated with 1,5 % water Heat the silica gel for at least 5 h at 130 °C, allow to cool in a desiccator, and store in a tightly stoppered container in the desiccator. To 98,5 g of dried silica gel in a 300 ml conical flask (with ground joint), add 1,5 ml of water dropwise from a burette with continuous swirling. Immediately stopper the flask with ground stopper, shake vigorously for 5 min until all lumps have disappeared, next shake for 2 h on a mechanical shaker, and then store in a tightly stoppered container. 7.2.21 Glass wool, extracted exhaustively with acetone 7.2.22 Cotton-wool, extracted exhaustively with acetone 7.2.23 BioBeads® S-X3, 38 µm to 75 µm (200 mesh to 400 mesh) 7.2.24 Filter paper, 6 cm and 13,5 cm diameter, fast flow rate, extracted exhaustively with acetone 7.3 Apparatus Usual laboratory equipment in accordance with EN 12393-1 and, in particular, the following: 7.3.1 High speed blender or homogenizer, with a suitable blender cup 7.3.2 Solvent evaporator, with a water bath 7.3.3 Instrument for GPC, e.g. GPC Autoprep 1001 or 1002® 5), equipped with chromatographic column, 25 mm internal diameter, 50 cm, and twenty-three 5 ml sample loops; column packing 50 g of BioBeads® S-X3 resin, pre-swelled overnight in the GPC eluting mixture, approximately 32 cm column height, packed as described in 7.4.3.2.
5) GPC Autoprep 1001 or 1002® are examples of a suitable product available commercially. This information is given for convenience of users of this standard and does not constitute an endorsement by CEN of these products. SIST EN 12393-2:2009

7.4.1.3 Plant material with low water content Weigh out 10 g to 50 g (m) of the dry or dried matrix having a water content of x g/100 g (for example 25 g to 50 g for dried fruit and dried vegetables; 10 g to 20 g for spices and tea; 50 g for cereal grains). Then add sufficient water to adjust the total water present to 100 g. The amount of water (W) to be added is calculated from the equation W = 100 - (m × x)/100. Blend and let stand for 10 min to 20 min. Next add 200 ml of acetone and homogenize for 3 min. 7.4.2 Partition 7.4.2.1 Partition with dichloromethane Add 10 g of Celite® 545 and again homogenize for 10 s. Filter the homogenate derived from 7.4.1.2 or 7.4.1.3 through a fast flow rate filter paper (7.2.24) in a Büchner funnel, with gentle vacuum suction, until more than 200 ml of filtrate is collected. To avoid losses of solvent due to strong vacuum, it is recommended only to use a low vacuum. Do not allow the filter cake to pull dry. Measure out 200 ml of filtrate (VR1) in a graduated cylinder, and transfer to a 500 ml separatory funnel. Add 20 g of sodium chloride (7.2.16), and shake vigorously for 3 min. Next add 100 ml of dichloromethane, shake for 2 min, and then let stand for approximately 10 min to allow the phases to separate. Discard the lower aqueous phase. Collect the organic phase in a flask and add approximately 25 g of sodium sulfate (7.2.17), let stand for approximately 30 min with occasional swirling, and then filter through a cotton-wool plug (7.2.22) layered with 3 cm of sodium sulfate in a funnel. Collect the filtrate in a 500 ml round-bottomed flask, and rinse separatory funnel and filter twice with 20 ml portions of ethyl acetate. Concentrate the solution to 2 ml on a rotary evaporator (7.3.2). Remove the last traces of solvent with a gentle stream of nitrogen. 7.4.2.2 Partition with cyclohexane/ethyl acetate To the homogenate derived from 7.4.1.2 or 7.4.1.3 add 35 g sodium chloride (7.2.16) and exactly 100 ml of GPC eluting mixture (7.2.6) to the same container and homogenize it again for 1 min. When the phases are clearly separated, collect the upper organic phase. In case of insufficient or delayed phase separation (more than 30 min) centrifuge the mixture. Measure out exactly 200 ml (VR1) of the organic phase in a graduated cylinder and filter this volume through a cotton-wool plug (7.2.22) layered with approximately 100 g sodium sulfate (7.2.17) in a funnel. Collect the filtrate in a 500-ml round-bottomed flask and rinse the graduated cylinder and the funnel four times each with approximately 20 ml GPC eluting mixture. Concentrate the combined filtrate to a watery residue (not to dryness) using the rotary evaporator (7.3.2). SIST EN 12393-2:2009

7.4.3.2 Packing gel permeation column Allow the BioBeads® (approximately 50 g) to swell overnight in the GPC eluting mixture (7.2.6). Then pour the suspension all at once into the column (capacity of approximately 180 ml). As soon as the gel bed has settled (free from air bubbles) to a level of approximately 32 cm, insert the plunger, lower it down to the bed level, and screw it into place. If the gel bed sinks to a still lower level after prolonged operation, the plunger shall be adjusted accordingly (observe manufacturer's instructions). 7.4.3.3 Checking elution volumes For each gel permeation column before the first use, the elution conditions shall be checked on several compounds of the lower and upper elution volume range (see Table 4), and on appropriate crude extracts. To do so, load the sample loop with crude extracts or a mixture of standard solutions, elute as described in step 7.4.3.4 and determine by means of a suitable analytical method whether the added compounds are completely recovered or whether interferences are caused by non-separated impurities. The same check shall be carried out on columns after they have been in use for a lengthy period. NOTE
It has been shown that some matrices can introduce randomized adsorption effect of certain analytes on BioBeads® resin and can cause false negative or false positive results. 7.4.3.4 Clean-up of crude extracts To the concentrated residue of a crude extract obtained in 7.4.2.1 or 7.4.2.2 add exactly 7,5 ml of ethyl acetate and dissolve by gentle swirling. Add approximately 5 g of salt mixture (7.2.18) for binding the remaining water, swirl again, and add exactly 7,5 ml of cyclohexane to yield a total volume of 15,0 ml (VR2). Shake for approximately 20 s, allow the salt mixture to settle and filter through a fast flow-rate filter paper, and inject the filtrate into one of the sample loops of the gel permeation chromatograph (VR3). Elute the gel permeation column with the GPC eluting mixture at a flow rate of 5,0 ml/min. The instrument switches of the gel permeation chromatograph are adjusted according to the checking of the elution volumes. The settings depend on the target pesticides. Typical settings are as follows (see also Table 4):  dump switch to 18 min to discard 90 ml;  collect switch to 15 min to collect 75 ml;  wash switch to 2 min for column rinse with 10 ml. Concentrate the collect volume to approximately 1 ml on a rotary evaporator (rotate slowly, immerse flask only slightly), pipette into a ground-stoppered graduated test tube, rinse the evaporator flask with ethyl acetate and dilute with ethyl acetate to a volume of 5,0 ml (VR4). This addition of ethyl acetate shall not be omitted on any account in order to ensure complete dissolution of the residue. For the determination of individual pesticide residues, the instrument can be set to a smaller collect volume, matched to the respective compound, according to the values given in Table 4. SIST EN 12393-2:2009

ml 1 2 3 4 5 Acephate 115 to 145 0 0 0 0 5 Aclonifen 115 to 145 0 5 0 0 0 Alachlor 125 to 150 0 0 5 0 0 Aldrin 120 to 150 5 0 0 0 0 Ametryn 115 to 190 0 0 1 3 0 Amidithion 115 to 145 0 0 0 4 3 Anilazine a 105 to 135 0 0 5 0 0 Anthraquinone 145 to 185 0 2 4 0 0 Atrazine 110 to 135 0 0 4 3 0 Azinphos-ethyl 130 to 160 0 0 5 0 0 Azinphos-methyl 145 to 180 0 0 4 0 0 Azoxystrobin 120 to 155 0 0 0 5 0 Benfluralin 100 to 130 5 0 0 0 0 Benzoylprop-ethyl 125 to 150 0 3 3 0 0 Bifenox 115 to 150 0 3 3 0 0 Bifenthrin 090 to 120 0 5 0 0 0 Binapacryl 100 to 130 0 5 0 0 0 Bitertanol 100 to 130 0 0 0 4 2 Boscalid 105 to 130 0 0 5 0 0 Bromacil b 105 to 140 0 0 0 5 0 Bromophos 120 to 150 4 2 0 0 0 Bromophos-ethyl 110 to 140 5 1 0 0 0 Bromopropylate 095 to 135 0 0 3 3 1 Bromoxynil 120 to 150 0 5 1 0 0 Camphechlor (Toxaphene) 110 to 150 5 1 0 0 0 Captafol c 120 to 150 0 0 5 0 0 SIST EN 12393-2:2009

ml 1 2 3 4 5 Captan c 120 to 150 0 0 5 0 0 Carbophenothion 120 to 140 0 3 0 0 0 Carbophenothion-methyl 120 to 160 0 4 0 0 0 Chinomethionat 170 to 200 0 1 4 0 0 (Quinomethionate) 170 to 200 0 1 4 0 0 Chlorbenside d 120 to 155 0 0 1 0 0 Chlorbenside sulfone 130 to 160 0 0 5 0 0 α-Chlordane 110 to 140 5 0 0 0 0 γ-Chlordane 100 to 130 5 0 0 0 0 Chlorfenapyr 085 to 105 0 5 0 0 0 Chlorfenprop-methyl 125 to 150 0 5 0 0 0 Chlorfenson 120 to 150 1 5 0 0 0 Chlorfenvinphos 110 to 140 0 0 4 3 0 Chloridazon 130 to 155 0 0 0 4 1 Chlormephos 115 to 145 3 3 0 0 0 Chlorobenzilate 100 to 135 0 0 4 2 1 Chloroneb 145 to 170 0 5 0 0 0 Chloropropylate 100 to 135 0 0 4 2 0 Chlorothalonil 125 to 165 0 5 0 0 0 Chlorotoluron 115 to 150 0 0 0 5 2 Chloroxuron 130 to 155 0 0 1 5 0 Chlorpropham 110 to 135 0 2 4 0 0 Chlorpyrifos 110 to 140 2 4 0 0 0 Chlor
...