Determination of Trace Pyrethroid Insecticides in River Water by Solvent Sublation Followed by High Performance Liquid Chromatography with Ultraviolet Detection

摘要

A novel method for separation and enrichment of trace pyrethroid insecticides from river water by solvent sublation and their subsequent determination by high performance liquid chromatography with ultraviolet detection (HPLC-UV) has been performed. n-Hexane was selected as a sublation solvent. The optimal conditions of sublation were: solution pH = 3, nitrogen flow rate 40 mL min~(-1), sublation time 60 min; Under the optimal conditions the floating product was determined by HPLC-UV using an Eclipse XDB-C18 chromatographic column, acetonitrile-water mobile phase in gradient eiution mode, and flow rate of 1.2 mL min~(-1). The proposed method was applied to the determination of eight pyrethroids in the river water from Beijing Fangshan District. The obtained recoveries ranged from 89 to 112%, RSDs ranged from 0.78 to 8.06%, and LOD values - from 0.03 μg L~(-1) for cypermethrin to 1.80 μg L~(-1) for cyhalothrin.