Development and multivariate optimization of nanostructured supramolecular liquid-liquid microextraction validated method for highly sensitive determination of methyl parathion in water samples

摘要

A simple, rapid and environmentally friendly supramolecular solvent-(SUPRAS)-based liquid phase microextraction method combined with high performance liquid chromatography (HPLC) for the determination of methyl parathion (MP) in water samples was developed. Several factors that affect the coacervation process, such as pH, volume and 1-decanol/THF ratio of supramolecular solvent, vortex time, and inorganic salt concentration were investigated and optimized. Under the optimized conditions, the enhancement factor and preconcentration factor were obtained as 139 and 12.7, respectively and the consumptive index (CI) was 0.79 mL. The limits of detection and quantification were found to be 0.27 mu g L-1 and 0.91 mu g L-1, respectively, while the linear range of analytical curve was ranged from 0.91 up to 500.0 mu g L-1 with correlation coefficient of 0.999. The precision was evaluated in terms of intra-day (n = 10) and inter-day (n = 2) repeatability and the relative standard deviation percentages (% RSD) for two-level concentration (5.0 and 200.0 mu g L-1) was <5.3%. Imazethapyr, imazapic and imazepyr evaluated as possible interfering molecules did not show interference in the microextraction process, while 200.0 mu g L-1 MP could be extracted in the respective presence of 2-nitrophenol and 4-nitrophenol at the 1:1 and 1:10 (m/m) ratio. The developed method was successfully applied for the determination of MP in artesian well (20.3 +/- 2.4 mu g L-1) and surface water (12.2 +/- 3.5 mu g L-1 and 12.7 +/- 2.6 mu g L-1). The accuracy was attested by addition and recovery tests of MP obtaining recovery percentages in the range of 92.0-109.9%, thereby confirming the reliability of the proposed method. (C) 2020 Elsevier B.V. All rights reserved.