Sensitive determination of pyrethroid insecticide residues in tea using a molecularly imprinted fiber array based on homemade solid-phase microextraction coatings

Abstract

In this study, we proposed a homemade solid-phase microextraction fiber array based on molecularly imprinted polymer coatings. This sample pretreatment technique was used prior to high-performance liquid chromatography (HPLC) to identify pyrethroids, of a class of high-efficiency insecticides for controlling plant pests and diseases in agriculture. Findings revealed that the molecularly imprinted three-fiber array for solid-phase microextraction significantly increased the extraction capacity by 2.1 to 3.5 times compared with a single molecularly imprinted fiber, and it also increased the extraction capacity by 2.0 to 3.4 times compared with two different commercial fiber arrays. The imprinted fiber array extraction coupled with the HPLC analytical method was effective and sensitive in an aqueous solution. In addition, this combined method improved the extraction and screening capacities of pyrethroid insecticides. The detection limits of pyrethroid insecticides in tea samples were 0.16–0.33 μg/L with linear correlation coefficients of 0.9900–0.9994. The spiked recoveries were 72.74–119.66 %, with RSD (n = 3) below 14.53 %. Thus, this work provides an effective, sensitive, and practical method with good enrichment effects for analyzing and determining of multiple pyrethroids in tea samples.