Simultaneous determination of fluoroquinolones in environmental water by liquid chromatography-tandem mass spectrometry with direct injection: A green approach

This work describes an on-line multi-residue method for simultaneous quantification of ciprofloxacin, enrofloxacin, gemifloxacin, moxifloxacin, norfloxacin and ofloxacin in superficial and wastewater samples. For that, an octyl restricted-access media bovine serum albumin column (RAM-BSA C8) was used for sample clean-up, enrichment and analysis with quantitation carried out by tandem mass spectrometry. For water samples volumes of only 500 μL the method provided good selectivity, extraction efficiency, accuracy, and precision with quantification limits in the order of 20-150 ng L−1. Out of the six fluoroquinolones only ciprofloxacin (195 ng L−1) and norfloxacin (270 ng L−1) were quantified in an influent sample of the wastewater treatment plant (WWTP) of São Carlos (SP, Brazil). None were found in the superficial water samples analyzed. The capability of injecting native sample in an automated mode provides high productivity and represents a greener approach in environmental sample analysis.