A systematic strategy for the identification and determination of pharmaceuticals in environment using advanced LC–MS tools: Application to ground water samples

•Determination of pharmaceuticals in ground water samples using optimized strategy.•Use of LC–MS/TOF and LC–MSn methodology.•Pharmaceuticals found in ground water in villages of Mohali district, India.•Diclofenac in ground water of four villages and pitavastatin in one village.

In the present study, a novel analytical strategy was employed to study the occurrence of 40 drug residues belonging to different medicinal classes, e.g., antibiotics, β blockers, NSAIDs, antidiabetics, proton pump inhibitors, H2 receptor antagonists, antihypertensives, antihyperlipidemics, etc. in ground water samples collected from villages adjoining to S.A.S. Nagar, Punjab, India. The drug residues were extracted from the samples using solid-phase extraction, and LC–ESI–HRMS and LC–ESI-MS/MS were used for identification and quantitation of the analytes. Initially, qualifier and quantifier MRM transitions were classified for 40 targeted drugs, followed by development of LC–MS methods for the separation of all the drugs, which were divided into three categories to curtail overlapping of peaks. Overall identification was done through matching of retention times and MRM transitions; matching of intensity ratio of qualifier to quantifier transitions; comparison of base peak MS/MS profiles; and evaluation of isotopic abundances (wherever applicable). Final confirmation was carried out through comparison of accurate masses obtained from HRMS studies for both standard and targeted analytes in the samples. The application of the strategy allowed removal of false positives and helped in identification and quantitation of diclofenac in the ground water samples of four villages, and pitavastatin in a sample of one village.

Graphical abstractNovel strategy employed for the determination of pharmaceuticals in water samples.Figure optionsDownload full-size imageDownload as PowerPoint slide