Validation of a multi-residue method for the determination of pesticide residues in apples by gas chromatography

Abstract

The validation of a multi-residue method for the determination of 16 pesticides in apple fruits is described. The method involves the extraction of pesticides using acetone, dichloromethane, and petroleum ether (40–60°C) and subsequent determination by a gas-chromatographic system with an electron capture detector. Among the tested compounds, there is kresoxim methyl, which belongs to a strobilurin class of fungicides developed from the natural substance, strobilurin. Apple samples were fortified in two levels and pesticide residues were determined. Recoveries, standard deviations, and limits of quantification (LOQ) were calculated. The lowest calculated LOQ value was 0.01 mg kg⁻¹ for the analyte λ-cyhalothrin, and the highest LOQ value was 0.15 mg kg⁻¹ for the analytes triadimefon and triadimenol, limits that satisfy the MRLs set by EU.

Keywords:

• Pesticides
• Residues
• Apples
• Food analysis