Session: Accurate Mass/High Resolution Mass Spectrometry for Environmental Monitoring & Remediation: Accurate Mass/High Resolution Mass Spectrometry for Environmental Monitoring & Remediation

High resolution LC-MS/MS methods were applied to the analysis of wastewater and river water samples taken from a heavily urbanised tidal river catchment area (London, UK). In this work, high resolution LC-MS/MS methods acquired precursor ion data in full scan MS mode and data independent analysis (DIA) product ion detection in MS/MS mode to support both targeted and suspect screening analysis. Using a targeted data analysis workflow, a number of illicit drug and pharmaceutical compounds were positively identified, each target was confirmed using accurate mass, isotopic distribution, retention time and accurate mass fragment spectrum data (a curated accurate mass MS/MS data base with over 900 compounds including retention times was used to increase reporting confidence). This approach positively identified commonly reported illicit street drugs such as cocaine and lidocaine (regularly used as an adulterant in illicit street drugs) and a number of antidepressant’s including selective serotonin re-uptake inhibitors (citalopram, fluoxetine, sertraline). To search for compounds outside the target panel a series of tools were used including component detection (to locate all ion signals in the sample), suspect screening search lists (to match molecular ion features), molecular formula prediction and to verify a putative candidate from a chemically-indexed database (such as PubChem or ChemSpider) a fragment structural annotation tool was used to correlate acquired MS/MS fragment structures with the molecular structure. Using this analysis, several other compounds were detected in the wastewater samples including serotonin and norepinephrine reuptake inhibitors such as venlafaxine.

Neil Loftus

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