Page 15 - Volume 2, Issue 1, January 2009

Hellenic Plant Protection Journal

2:

15-22, 2009

Method validation for the determination of pesticide residues

in wheat flour by gas chromatography

C.J. Anagnostopoulos

1

and G.E. Miliadis

1

Summary

A rapid multi-residue method for the simultaneous determination of residues of 28 multi-

class representative pesticides is presented. The 28 pesticides were included in the 2007 Proficiency

Test for cereals, organized by the European Commission Reference Laboratories on Cereals and Feed-

ingstuff and Single Residue Methods. The extraction was based on acetone – dichloromethane – pe-

troleum ether and the analysis was performed by gas chromatography (GC) with ECD and NPD de-

tectors. The procedure was applied to the screening, confirmation and quantification of the 28 pesti-

cides. The recoveries obtained from the validation data were from 66 to 120% with relative standard

deviation (RSD) <10% and the attained limits of quantification were between 0.01 and 0.75 mg/kg. The

method is characterized by good accuracy, precision and sensitivity.

Additional keywords

: cereals, GC-ECD, GC-NPD, multi-residue, proficiency test

11) proposed the extraction of pesticides

from agricultural products with acetone,

and liquid-liquid partitioning cleanup for

determination of several pesticides by gas

(GC) and liquid (LC) chromatography.

The objective of this study was to devel-

op and validate a simple and rapid method

for the determination of the pesticides used

in the 2007 Proficiency Test C1-SRM2 orga-

nized by the CRL laboratory for cereals (Na-

tional Food Institute, Department of Food

Chemistry, Danish Technical University) on

behalf of the European Commission. The

sample of the test was wheat flour and the

extraction was based on the DutchMinistry

of Public Health, Welfare and Sport (12) ace-

tone – dichloromethane – petroleum ether

multiresidue method extraction procedure.

Determination was performed by GC-NPD/

ECD and validation levels encompassing the

minimum required performance levels (MR-

PLs) were achieved.

Materials and Methods

1. Chemicals and solvents

The following pesticide analytical stan-

dards (obtained from Dr Ehrenstorfer Labo-

Introduction

The requirements related to sampling and

analysis are set out in Article 11 and Annex

III of Regulation 882/2004. Sampling and

methods of analysis used for official control

purposes should, wherever possible, be rec-

ognised by international organisations and

be validated in accordance with Community

legislation or with internationally accepted

protocols. Article 32 of Regulation 882/2004

establishes the Community Reference Labo-

ratories (CRLs) for food and feed. According

to this article the CRLs are responsible for

organization of Proficiency Tests. The objec-

tive of a proficiency test is to obtain informa-

tion about the quality, accuracy and compa-

rability of the pesticide residue data sent to

the European Commission within the frame-

work of the EU and national pesticide moni-

toring programs.

Many analytical methods have been

studied for the simultaneous determination

of multi-pesticide residues. In 1975 Luke (9,

1

Laboratory of Pesticide Residues, Department of

Pesticides Control and Phytopharmacy, Benaki Phy-

topathological Institute, 8 St. Delta str., GR-145 61 Ki-

fissia (Athens), Greece.

Corresponding author:

C.Anagnostopoulos@bpi.gr