Solid phase microextraction using a graphene composite-coated fiber coupled with gas chromatography for the determination of acetanilide herbicides in water samples

Abstract

A graphene composite-coated stainless steel solid-phase microextraction fiber was prepared. The applicability of the fiber was evaluated through the solid-phase microextraction of five acetanilide herbicides (alachlor, acetochlor, pretilachlor, butachlor and metolachlor) in water samples followed by gas chromatography-electron capture detection. Parameters that affect the extraction efficiency, including the extraction time, extraction temperature, pH of the sample solution, stirring rate and desorption conditions were investigated and optimized. The linear response for the analytes was observed in the range from 0.8 to 150.0 μg L⁻¹ with the correlation coefficients (r) ranging from 0.9933 to 0.9970 and the limits of detection (LODs) between 0.06 and 0.10 μg L⁻¹. The single fiber repeatability and fiber-to-fiber reproducibility were less than 6.2% and 11.2%, respectively. The recoveries of acetanilides from water samples by the current method at spiking levels of 10.0 and 100.0 μg L⁻¹ fell in the range from 81.8% to 112.0%.