Headspace in-tube microextraction combined with reverse-flow micellar electrokinetic capillary chromatography for detection of pyrethroid herbicides in fruits

Abstract

A rapid, simple, and sensitive method has been developed for the analysis of pyrethroid herbicides in fruits by using headspace in-tube microextraction (HS-ITME) coupled with reverse-flow micellar electrokinetic capillary chromatography (RF-MECC). In the newly developed method, by placing a capillary filled with background electrolyte (BGE) of RF-MECC in the HS above the sample solution, the pyrethroid herbicides were extracted into the acceptor phase in the capillary. After extraction, electrophoresis of the extracts in the capillary was carried out. The influence of some essential BGE components such as sodium dodecyl sulfate (SDS) and organic modifiers concentrations was investigated. Extraction parameters were also systematically investigated, including the extraction temperature, extraction time, salt concentration, and volume of the sample solution. Under the optimized conditions, enrichment factors for three pyrethroids were 309, 133, and 288, respectively. The proposed method provided a good linearity, low limits of detection (below 1.00 ng/mL), and good repeatability of the extractions (relative standard deviations [RSDs] below 7.83%, n = 6). The fruit samples were analyzed by the proposed method, and the obtained results indicated that the proposed method provides acceptable recoveries and precisions.