Analysis of Organophosphorus Pesticides (OPPs) in Paddy Field Water Using IL-DLLME

Abstract

The application of organophosphorus pesticides (OPPs) is extensively used to combat the pest attack and massively used including in paddy field. The OPP is an effective pesticide with broad killing spectrum that exhibits less environmental persistence, but the residue is highly toxic to us. Hence, in this work, determination of four types of OPPs compound, that is, parathion-methyl (PM), azinphos-methyl (AM), diazinon (D), and malathion (M) in paddy field water samples at four location in Perlis state was done. Sample extraction was carried out using ionic liquid dispersed liquid–liquid microextraction (IL-DLLME). Two types of ionic liquid, 1-butyl-3-methylimidazolium bromide [BMIM][Br] and 1-butyl-3-methylimidazolium chloride [BMIM] [Cl], were used as an extraction solvent. The effect of extraction time (ET), centrifugation time (CT), and concentration (C) on the ILs was investigated. Sample analysis was carried out using high-performance liquid chromatography with photodiode detector (HPLC-PDA). The result showed that 1 h of ET and 10 min of the CT were optimum parameters in this work. The linear correlation (R2) of the OPPs standard was 0.9979, 0.9988, 0.9988, and 0.9993 for AM, PM, M, and D, respectively. The LOD and LOQ values for [BMIM] [Br] range from 0.01 to 1.71 µg/L and 0.03 to 1.42 µg/L, respectively, while LOD and LOQ values for [BMIM] [Cl] range from 2.9 to 10.4 µg/L and 13.7 to 20.59 µg/L, respectively. The concentration of the analyte ranges from 3.7 to 16.8 ppm, 17.5 to 69.9 ppm, and 2.8 to 58.1 ppm in Beseri, Mata Ayer, and Arau water samples, respectively.