Incorporating PET-MIL-101(Fe) within cellulose acetate membrane for thin film microextraction of neonicotinoid insecticides in water.

Herein, cellulose acetate membrane modified with polyethylene terephthalate derived MIL-101(Fe) (PET-MIL-101(Fe)) was used as an extraction phase for the direct immersion-thin film microextraction method (DI-TFME) of neonicotinoid insecticides in water samples. The quantitative analysis of clothianidin, imidacloprid, thiacloprid and thiamethoxam was carried out using high-pressure liquid chromatography (HPLC-DAD). The morphological and structural characteristics of the materials were studied using transmission electron microscopy (TEM), X-ray diffraction analysis (XRD), and energy dispersive X-ray spectrometry (EDX). Under optimum conditions, acceptable analytical performance for the developed DI-TFME/HPLC-DAD method was attained. The linearity of the method ranged from 0.04 to 500 µg/L with R2 ranging from 0.9981 to 0.9989. The detection limits, quantification limits and relative standard deviation (%RSD) of the DI-TFME/HPLC-DAD method were in the range of 0.013-0.016 µg/L, 0.043-0.053 µg/L and 1.2-3.9%, respectively. The method was applied in the analysis of real water samples, and the spiking recoveries of the target analytes were 95.6-102%, 91.2-98.6% and 79.2‒98.7% for river water, effluent and influent samples, respectively, with %RSDs ranging from 1.8 to 4.8%. These findings demonstrated that the developed DI-TFME/HPLC-DAD method had high precision, accuracy, sensitivity and enrichment factor (73-88). The DI-TFME/HPLC-DAD method proved sustainable for the simultaneous quantification of trace neonicotinoid insecticides in real samples.