Quadrupole time-of-flight versus triple-quadrupole mass spectrometry for the determination of non-steroidal antiinflammatory drugs in surface water by liquid chromatography/tandem mass spectrometry.
A triple-quadrupole instrument and a hybrid quadrupole/time-of-flight (TOF) mass spectrometer were compared for the determination of pharmaceutical compounds in water samples. The drugs investigated were the analgesics Ibuprofen, Fenoprofen, Ketoprofen, Naproxen, and Diclofenac. The recently introduced Q2-pulsing function, which enhances the transmission of fragment ions of a selected m/z window from the collision cell into the TOF analyzer, improved the sensitivity of product ion scans on the quadrupole/TOF instrument. The selectivity is much better on quadrupole/TOF systems than on triple quadrupoles because the high resolving power of the reflectron-TOF mass analyzer permits high-accuracy fragment ion selection. This minimizes interferences from environmental matrices and allows acquisition of full spectra for selected analytes with better signal-to-noise characteristics than comparable spectra obtained with a scanned quadrupole. The qualitative information obtained (mass accuracy, resolution and full-scan spectra) by hybrid quadrupole/TOF mass spectrometry allows a more certain identification of analytes in environmental matrices at trace levels. Sample enrichment of water samples was achieved by a solid-phase extraction procedure. Average recoveries for loading 1 L of samples varied from 88 to 110%, and the quantification limits were less than 1.2 ng/L for the triple-quadrupole instrument (in MRM mode) and less than 3 ng/L for the quadrupole/TOF instrument.
Marchese
Stefano
S
Dipartimento di Chimica, Università "La Sapienza" di Roma, Piazzale Aldo Moro n degrees 5, PO Box 34, Posta 62, 00185 Roma, Italy. stefano.marchese@uniromal.it
Gentili
Alessandra
A
Perret
Daniela
D
Ascenzo
Giuseppe D'
GD
Pastori
Federico
F
D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D007202:Indicators and Reagents; D013058:Mass Spectrometry; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014881:Water Supply / Q000032:analysis*
D000894:Anti-Inflammatory Agents, Non-Steroidal; D007202:Indicators and Reagents; D014874:Water Pollutants, Chemical