Assessment of three SPE cleanup sorbents efficiencies for determining neonicotinoid insecticides and selected metabolites in honey bees and bee pollen

Abstract

Three sample cleanup methods (silica SPE, NH2‐silica SPE, and Z‐Sep SPE) based on solid‐phase extraction were investigated for determination of neonicotinoid insecticides and selected metabolites in honey bee and pollen samples by liquid chromatography with tandem mass spectrometry. Samples were extracted by acidified hexane and ethyl acetate and then cleaned up with a solid‐phase extraction cartridge packed with silica gel, which showed a better cleanup efficiency compared to the aminopropyl silica solid‐phase extraction and zirconium‐based sorbents method. Matrix effects of the three cleanup methods were evaluated and compared. Silica gel showed the highest analyte recoveries and method detection limit for this method were 2.0 to 9.1 μg/kg for honey bees and 2.4 to 4.7 μg/kg for pollen. Recovery studies were performed at three spiking levels (10, 60, and 120 μg/kg) and ranged from 78 to 140% with relative standard deviations between 3 to 18% in honey bees and 83 to 124% with relative standard deviations between 3 to 17% in pollen. The silica gel solid‐phase extraction cleanup method was then applied using honey bee and pollen samples that were collected from different apiaries.