Three-pesticide residue analysis in tomato using a fast pressure variation in-syringe dispersive liquid-phase microextraction technique coupled with gas chromatography-mass spectrometry by assisting experimental design

Abstract

ABSTRACT In this study, an analytical procedure based on a pressure variation in-syringe dispersive liquid–phase microextraction method coupled with gas chromatography-mass spectrometry by using experimental design methods is introduced for determining diazinon, malathion and chloropyrifos in tomato samples. In the proposed method, chloroform is selected as an extraction solvent. The screening strategy is done by using Plackett–Burman design. The volume of extraction solvent, ionic strength, extraction time and pH are statistically significant, Optimal conditions for these variables were determined. The calibration curves were linear in the range of 10.0–200.0 μg Kg−1, 10.0–100.0 μg Kg−1, and 10.0–50.0 μg Kg−1, with determination coefficients of 0.9999, 0.9993 and 0.996 for diazinon, malathion and chloropyrifos respectively. The detection limits were found to be 6.3 μg Kg−1 for diazinon, 7.1 μg Kg−1 for malathion and 4.8 μg Kg−1for chlorpyrifos. The inter-day and intra-day precision (RSD%) were 2.88% and 8.66% for diazinon, 0.92% and 4.45% for malathion and 3.63% and 5.78% for chloropyrifos (n = 5, concentration = 20 μg Kg−1). The pressure variation in-syringe -DLLME method was used to determine OPPs for the first time in this study.