In-Tube Ultrasound Assisted Dispersive Solid–Liquid Microextraction Based on Self-Assembly and Solidification of an Alkanol-Based Floating Organic Droplet for Determination of Pyrethroid Insecticides in Chrysanthemum

Abstract

A new in-tube pretreatment method based on ultrasound assisted dispersive solid–liquid microextraction using self-assembly and solidification of an alkanol-based floating organic droplet was developed for the determination of eight pyrethroid insecticides in chrysanthemum by gas chromatography with electron capture detection. This method fully utilized the restricted access property of a 1-decanol/acetonitrile mixture for effective extraction of the analytes from chrysanthemum under ultrasonication, and the self-assembly and coacervation process of 1-decanol by adding water. The 1-decanol phase aggregated and floated on the surface, solidified in an ice bath, and thus was easily collected. For the first time, extraction, separation and preconcentration were combined in a tube, not requiring stepwise preparation for a solid matrix. The recoveries ranged from 75 to 104% with the relative standard deviations of < 8%. The limits of quantification were in the range of 0.15–1.5 µg kg− 1 up to 52-fold compared with the conventional QuEChERS-based, SPE, and solid–liquid dispersive microextraction methods. The results demonstrated that the proposed method was time-saving, sensitive, and environmentally friendly for pyrethroids analysis in chrysanthemum.