Multi-residue enantioselective determination of emerging drug contaminants in seawater by solid phase extraction and liquid chromatography-tandem mass spectrometry

• Published in: Analytical methods Vol. 12; no. 22; p. 2881
• Main Authors: McKenzie, Katie, Moffat, Colin F, Petrie, Bruce
• Format: Journal Article
• Language: English
• Published: England 11-06-2020
• Subjects: Chromatography, Liquid; Pharmaceutical Preparations; Scotland; Seawater; Solid Phase Extraction; Stereoisomerism; Tandem Mass Spectrometry; Water Pollutants, Chemical - analysis; Scotland
• ISSN: 1759-9679
• DOI: 10.1039/d0ay00801j

This study proposes a new multi-residue enantioselective method for the determination of emerging drug contaminants in sea water by solid phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). To achieve satisfactory enantiomeric separation with a vancomycin stationary phase it was essential to limit sodium chloride in extracted samples to <1 μg per injection. This was achieved through a straightforward SPE method using a 50 mL water wash volume and analyte elution in acetonitrile. A Chiral-V enantioselective column (150 × 2.1 mm; 2.7 μm particle size) operated in polar ionic mode enabled simultaneous drug separations in 30 minutes. Analytes with enantioresolution ≥1 were the stimulants amphetamine and methamphetamine, the beta-agonist salbutamol, the beta-blockers propranolol, sotalol and acebutolol, the anti-depressants fluoxetine, venlafaxine, desmethylvenlafaxine and citalopram, and the antihistamine chlorpheniramine. Method quantitation limits were <10 ng L-1 and method trueness was 80-110% for most analytes. The method was applied to samples from the Forth and Clyde estuaries, Scotland. Chiral drugs were present at concentrations in the range 4-159 ng L-1 and several were in non-racemic form (enantiomeric fraction ≠ 0.50) demonstrating enantiomer enrichment. This emphasises the need for further enantiospecific drug exposure and effect studies in the marine environment.