Optimized combination of dilution and refined QuEChERS to overcome matrix effects of six types of tea for determination eight neonicotinoid insecticides by ultra performance liquid chromatography–electrospray tandem mass spectrometry

In this study, sample preparation by a refined QuEChERS method combined with a dilution strategy removed almost all matrix effects caused by six types of tea. Tea samples were soaked with water and extracted with acetonitrile, cleaned up with a combination of PVPP (160mg) and GCB (20mg), and dried. Dried extracts were diluted with 20mL acetonitrile/water (15:85, v/v) before analysis by UPLC–MS/MS. The average recoveries of eight neonicotinoid insecticides (dinotefuran, nitenpyram, thiamethoxam, imidacloprid, clothianidin, imidaclothiz, acetamiprid, and thiacloprid) ranged from 66.3 to 108.0% from tea samples spiked at 0.01–0.5mgkg−1. Relative standard deviations were below 16% for all recovery tests. The limit of quantification ranged from 0.01 to 0.05mgkg−1.

Source: Food Chemistry - April 27, 2016 Category: Food Science Source Type: research