Determination of Organophosphorus Pesticide Residues in Vegetables by Carbon Aerogel Dispersive Solid Phase Extraction Combined with Gas Chromatography

Abstract

A method for the determination of sulfotep, dimethoate, fenitrothion, parathion, methidathion, triazophos and azinos residues in vegetables and fruits by dispersive solid phase extraction (SPE) using a carbon aerogel-based sorbent combined with gas chromatography (GC) was developed. Solvent type, extraction time, the amounts of sodium chloride and purifying agent, and purification time were optimized. The results showed that the optimum conditions were determined as follows: acetonitrile as extraction solvent, 15 mg of carbon aerogel, 2.0 g of sodium chloride, extraction time 6 min, and purification time of 0.5 min. Under these conditions, good linearity was observed for all analytes in the concentration range of 0.01–3.0 μg/mL, with correlation coefficients of 0.999 0–0.999 8, and the detection limit at a signal to noise ratio of 3 was 0.4–1.0 μg/kg. The mean recoveries of spiked samples at three concentrations were 85.5%–102%. The developed method is simple, rapid, low-cost and suitable for the determination of organophosphorus pesticide residues in fruit and vegetable samples.

Keywords

• vegetables and fruits; gas chromatography; carbon aerogel; organophosphorus pesticides; dispersive solid phase extraction