© Benaki Phytopathological Institute
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:
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