SINGLE-DROP MICROEXTRACTION FOR THE DETERMINATION OF ORGANOPHOSPHORUS PESTICIDES IN WHEAT

Abstract

An analytical procedure has been developed for determining a group of six organophosphorus pesticide commonly used in crop production. A single-drop microextraction (SDME) method was analysed for the determination of organophosphorus pesticides (OPPs) dichlorvos, phorate, fenitrothion, malathion parathion, quinalphos in wheat sample. In this work single-drop microextraction (SDME) was analysed by gas chromatography mass spectrometer (GC-MS) with electron ionization detection (GC-EID) combining positive ion mode. The significant parameters affecting the single-drop microextraction (SDME) performance such as selection of solvent type, drop volume, stirring rate, extraction time, and effect of salt concentration has been examined. An attempt was made to optimize the parameters. The most common technique was applied for extraction of organophosphorus pesticides (OPPs) are liquid phase extraction. Overall, extraction was achieved by suspending a 1.5 pl toluene drop to the tip of a microsyringe immersed in a five ml doner aqueous solution containing 2.5% NaC1 (w/v) and stirred at 800 rpm. The limits of detection (LODs) in wheat sample for the six studied compounds were between 024 and 0.62 gg/m1 with the standard deviations ranging from 1.47 to 17.02%. Linear response data was obtained in the concentration range of 0.5-50 gg/m1 with correlation coefficients from 0.9526 to 0.9875. Sample of wheat grain collected from local market of Roorkee. Overall single-drop microextraction (SDME) method proved to be a fast and simple determination of organophosphorus pesticides (OPPs) in wheat sample.