Liquid chromatographic–electrospray tandem mass spectrometric determination of novel antifungal agents in plasma

A rapid, selective, sensitive and reproducible HPLC–electrospray tandem mass spectrometric method has been developed for the analysis of novel triazole antifungal agents, SYN-2869 and its derivatives (SYN-2836, SYN-2903 and SYN-2921), in rat plasma using SYN-2506 as an internal standard. Isolation of these compounds from plasma and sample desalting were performed by a simple extraction procedure involving protein precipitation, vacuum-drying and reconstitution with acetonitrile. For all the agents, linearity was observed over the range of 10–10 000 ng/ml (r≥0.996) and the limit of quantitation was 10 ng/ml using a 100-μl plasma volume. A measurement rate of 400–500 samples/day/instrument could be achieved using this method.