NATIONAL FOODADMINISTRATION

Multi-residue Methods used for Pesticides Residues Analysis of Fruits

and Vegetables in Sweden

Arne Andersson

National Food Administration

Sweden

NATIONAL FOODADMINISTRATION

Analytical method• A multi-residue method (M001/101) using ethyl acetate extraction and GPC clean-up was the main method during 1989-2003

• Determination of residues was done using GC (ITD, ECD, FPD, NPD) and HPLC

•Scope: about 200 pesticides and metabolites in one single analysis

•For acidic crops, NaOH was added and a new extraction was carried out (M002/102)

NATIONAL FOODADMINISTRATION

Determination by LC-MS/MS and GC equipped with conventional detectors

• In 2004 the HPLC determination was replaced by LC-MS/MS

• No GPC clean-up was needed

• Sensitive and selective provides quantification and confirmation at the same time

• LOQ: 10 ppb (0.01 mg/kg) for most pesticides

NATIONAL FOODADMINISTRATION

The new extraction procedure for all crops,used from 1 January 2005

• Ethyl acetate and addition of 15 g NaHCO3, to all crops. This increased the pH to 6-8 in acidic fruits and vegetables

• By this small change two old multi-methods could be substituted by one new method (M200)

• The determination is carried out by LC-MS/MS, GC-ITD and GC-ECD

NATIONAL FOODADMINISTRATION

P resen t m u lti m e thod for fru it andvege tab les

G C (ITD , EC D )about 180 ana lytes

LC -M S/M Sabout 120 ana lytes

D eterm ination

Filtra tion

Extraction w ith e thyl aceta teNaHC03 and Na2S04

NATIONAL FOODADMINISTRATION

LC -M S/M S m ethod

LC -M S/M SQ -Trap AP I 4000

500 µ l E tAc/C -hexane extract =>1500 µ l in M eOH

2 ,5 g sam ple /m l

adjust to 5 ml in ethyl acetate/cyclohexane (1+1)7 ,5 g sam ple /m l

100 m l a liquote => 1 m l

75 g sam ple + 200 m l e thyl ace ta te+ 15 g N aH C03 + N a2S04

NATIONAL FOODADMINISTRATION

Benefits of using LC-MS/MS determination

• No GPC clean-up is needed

• Selective, provides quantification and confirmation at the same time

• Better reproducibility for polar pesticides compared with GC

• LOQ: 10 ppb (0.01 mg/kg) for most pesticides

NATIONAL FOODADMINISTRATION

Change to GC-MS/MS determination

The goal is to change from using GC –ITD and GC-ECD to GC-MS/MS by 1 July 2006

NATIONAL FOODADMINISTRATION

Im p roved m u lti m e thod fo r fru it andvege tab les by 1 Ju ly 2006

G C -M S/M Sabout 110 ana lytes

LC -M S/M Sabout 190 ana lytes

D eterm ination

Filtra tion

Extraction w ith e thyl ace ta teNaHC03 and Na2SO 4

NATIONAL FOODADMINISTRATION

G C m ethod for d ith iocarbam ates

G C -FPD (S)

LOQ 0,025 mg/kg

w ater ba th 80°C , 60m in

50g sam ple150 m l tin ch lo ride /H Cl

25 m l isooctane

NATIONAL FOODADMINISTRATION

N ew m ulti m ethod for cereals

LC -M S/M Sabout 80 ana lytes

D eterm ination

Filtra tion

Extraction w ith aceton itrileN aCl and M gSO 4

Sam ple and w ater

NATIONAL FOODADMINISTRATION

EU Analytical Quality Control Guidelines

The revised version: SANCO/10232/2006, 24 March 2006

“Quality Control Procedures for Pesticide Residues Analysis”

Major updates:

• Confirmation using LC-MS/MS and GC-MS/MS

• Uncertainty and enforcement

http://europa.eu.int/comm/food/plant/resources/qualcontrol_en.pdf

Organizer: Tuija Pihlström, National Food Administration, Sweden

NATIONAL FOODADMINISTRATION

EU Proficiency Test 7, 2005

List with 62 pesticides

16 of the pesticides were applied to a sample of grapes

125 labs in 27 countries participated

Satisfactory results (Z-scores <2):

79 – 96% for the individual pesticides present

Organizer: Amadeo Fernández-Alba, University of Almeria, Spain

NATIONAL FOODADMINISTRATION

Homepage: www.slv.se

Thanks for your attention