DETERMINATION OF THE ORGANOCHLORINE PESTICIDE RESIDUES CONTENTS IN GRAPES BY SBSE-TD-GC-ECD ANALYSIS

Abstract

Stir bar sorptive extraction (SBSE)-thermal desorption (TD) procedure combined with gas chromatography electron capture detection (GC–ECD) was applied to the determination of 20 organochlorine pesticides (OCPs) in six white Romanian grape varieties. Analyses were performed using stir bars coated with 1.0 mm polydimethylsiloxane. The method provided satisfactory analytical performance to monitor OCPs in grape matrices at the trace level. By using the standard addition methodology, good linearity (r²>0.99) was found for all cases, depending on the particular OCP and also good sensitivity was achieved for all the investigated OCPs in agreements with the European Union regulations for the maximum residue limits (MRLs) of pesticides in agricultural vegetables. The method has multiple advantages, such as: simplicity, almost solventless and requires low sample amount, in comparison with conventional methods of sample preparation to analyse pesticides in vegetable matrices. The obtained results showed that OCPs were detected in all the investigated grape samples, with total contents varied between 0.32 µg/kg and 3.48 µg/kg, the concentrations were much lower than their specific MRLs.