Evaluation of the honeybee exposome in European apiaries by combining passive samplers and liquid chromatography with Zeno trap-time-of-flight mass spectrometry

This study introduces an analytical methodology that combines passive sampling with ultra-high pressure liquid chromatography coupled with a high-end quadrupole-time-of-flight mass spectrometer (UHPLC-QTOF-MS) for monitoring the honeybee (Apis mellifera L.) exposome across various European regions and seasons. The sampling methodology employs the recently developed adsorb pesticide in-hive strips (APIStrip) passive samplers, which use TENAX® TA adsorbent, to collect a wide range of chemicals when placed inside beehives. Following acetonitrile-based desorption, extracts were analyzed by UHPLC-QTOF-MS, equipped with an advanced ion trap –the Zeno trap– that enhances tandem-mass spectrometry (MS/MS) signals and improves mass accuracy, facilitating efficient feature annotation.

A non-targeted analysis (NTA) approach, combined with multivariate analysis, was used to simultaneously identify exposure analytes (e.g.natural products) and effect-related metabolites associated with honeybee health and condition (e.g. pheromones and other compounds emitted by bees). This methodology revealed geographical and seasonal variations in the chemical profiles of honeybee hives. In the evaluated Nordic countries, natural products from plants and pollen, along with bee-emitted substances such us neurotransmitters and pheromones, were prevalent. Seasonal analysis in Denmark revealed distinct chemical profiles associated with blooming flowers and peak brood rearing activity in April. This integrated, non-invasive methodology has proven highly effective in assessing the honeybee exposome, providing valuable insights into how environmental factors influence the chemical profiles emitted by bees.