Analysis of Pesticide Residues in Vegetables by Gas Capillary Chromatography

Abstract

A multiresidue analysis of 39 pesticides has been developed, as a rapid screening method for pesticide residues in vegetable samples. Gas chromatography with a) cold on column injection, DB-608 megabore column and nitrogen-phosphorus detection (NPD) and b) splitless injection, SE-52 capillary column and electron capture detection (ECD) was employed for the separation and identification of 15 compounds sensitive to NPD and 24 sensitive to ECD. The extraction methods included blending of small sample quantity with organic solvent, filtration and concentration.

The method's accuracy and precision were assessed in tomato matrix. Twelve target compounds, that are mainly used in the tomato cultivation in Greece, were selected from the 39 pesticides for this purpose, 6 of them sensitive to NPD and 6 sensitive to ECD. The recovery values for the NPD-sensitive compounds were 92.0–108.5% with relative standard deviations 0.6–8.4%, while recoveries for the ECD-sensitive compounds were 82.9–97.8% with relative standard deviations 0.81–14.8%. The estimated limits of detection for all studied compounds were between 0.001 and 0.01 mg/kg.

Key Words:

• Pesticide residues
• gas capillary chromatography
• vegetables