Analysis of Pesticide Levels in Honey and Pollen from Irish Honey Bee Colonies Using a Modified Dutch Mini-Luke Method with Gas and Liquid Chromatography-Tandem Mass Spectrometry Detection

Determining the levels of agrochemicals, such as pesticides,thathoney bees are exposed to is critical for understanding what stressfactors may be contributing to colony declines. Although several pesticidedetection methods are available for honey, limited work has been conductedto adapt these methods for pollen. Here, we address this gap by modifyingthe Dutch mini-Luke extraction method (NL method) for pesticide analysisin honey and pollen from throughout the island of Ireland. The NLmethod was modified to enable detection in small-sized samples andvalidated for both pollen and honey matrices. The modified NL methodcombined with liquid and gas chromatography-tandem mass spectrometrygave consistent results in terms of accuracy and precision measuredby recovery experiments and was successfully applied in the analysisof a range of pesticide residues. The modified NL method developedhere provides a key tool for detecting pesticides in honey bee colonyresources and the environment more broadly.