Platform-Independent Suspect Screening Analysis of Pesticides and Transformation Products in Honey Bees across Multiple High-Resolution Mass Spectrometers

When investigating honey bee suspected poisoning events, traditional targeted methods may overlook relevant compounds. Thus, a suspect screening workflow combining two complementary and platform-independent strategies in parallel, an exact mass screening tool and a combinatorial analysis of tandem mass (MS2) spectra, was developed to enhance exposure coverage. Its performance was assessed across three distinct high-resolution mass spectrometers (HRMS), using well-defined quality assurance and quality control metrics to ensure transparent and reproducible reporting of nontargeted analyses. True positive rates exceeded 80% across instruments during exact mass feature detection. Incorporating MS2-based annotation further improved identification confidence, with few false positives (≤9). Applied to incurred bee samples, the workflow identified atrazine and two transformation products, deethylatrazine and deisopropylatrazine. Overall, this workflow provides a comprehensive framework for investigating bee poisoning incidents and represents an important step toward improving the transfer of suspect screening workflows and the comparability of HRMS data across laboratories.