Determination of Phosphorothioate Pesticides in Environmental Water by Molecularly Imprinted Matrix Solid-Phase Dispersion Coupled with Gas Chromatography and a Nitrogen Phosphorus Detector

Abstract

Molecularly imprinted matrix solid-phase dispersion coupled with gas chromatography (GC) is reported for the separation of tolclofos-methyl, phoxim, chlorpyrifos, and parathion-methyl from environmental waters. Molecularly imprinted polymer microspheres were synthesized using the structural analog tolclofos-methyl as a dummy template via surface grafting polymerization on nanosilica. The pesticides were extracted using the molecularly imprinted polymers and determined by gas chromatography using a nitrogen phosphorus detector. The results indicate that the interferences from the sample matrix were eliminated. The calibration graphs for the analytes were linear from 0.01–4.0 µg L⁻¹. The limits of the detection for the pesticides were between 0.8 and 2.7 ng L⁻¹ in environmental water. The recoveries at two fortification levels were between 83.2 and 105.4% with relative standard deviations less than 8.3%.

Keywords:

• environmental water
• gas chromatography
• molecularly imprinted polymers
• phosphorothioate pesticides
• solid-phase dispersion

ACKNOWLEDGMENT

The authors also acknowledge Prof. Zuoxiong Liu for amending this article.