Reference library for suspect screening of environmental toxicants using ion mobility spectrometry-mass spectrometry

Due to the potential health risks related to chemical exposure, rapidly assessing xenobiotic molecules in the environment and those already in the body is imperative. Targeted analytical methods coupling either gas or liquid chromatography with mass spectrometry (GC-MS or LC-MS) are commonly utilized in current exposure assessments. While these methods are accepted as the gold standard for exposure analyses, they often require multiple sample preparation steps and analysis times > 30 min. These limitations have resulted in an evolving interest in using ion mobility spectrometry and MS (IMS-MS), either with or without chromatography, to improve throughput and annotation confidence. To increase IMS-MS information availability for exposure studies, here we utilized drift tube IMS-MS to evaluate 4685 xenobiotic chemical standards from the Environmental Protection Agency Toxicity Forecaster (ToxCast) programme, including pesticides, industrial chemicals, pharmaceuticals, consumer products, and per- and polyfluoroalkyl substances. Collision cross section (CCS) and m/z values were detected for 2144 unique chemicals with high confidence and reproducibility (≤1% error intra-laboratory and ≤2% inter-laboratory), resulting in values for 4004 [M + H]⁺, [M+Na]⁺, [M-H]^- and [M]^•+ ion types. This multidimensional database therefore supports suspect screening for a wider range of environmental contaminants, faster exposure response times, and assessments of xenobiotic-disease connections.