Fast, fully automated analysis of voriconazole from serum by LC-LC-ESI-MS-MS with parallel column-switching technique

Voriconazole is a novel broad-spectrum antifungal agent. We developed an on-line LC-LC-MS-MS method for fully automated and direct analysis of voriconazole in raw human serum. After injection of human serum size-selective sample fractionation and analyte extraction was achieved using an extraction column (25 mm x 4 mm) packed with a restricted access material (RAM, LiChrospher(R) ADS C-8, 25 mum). On-line transfer of voriconazole from the extraction column was followed by chromatography separation on a C-18 column. Detection was done by ESI-MS-MS. The total analysis time was 13 min, managed by parallel extraction and chromatographic separation. This LC-MS assay was fully validated. The lower limit of quantification was 0.05 mug/ml. The automated inline extraction of voriconazole described here eliminates the need for difficult and time-consuming sample pre-treatment. Other advantages of the new method are that only a small quantity (5 mul) of serum is needed and that the method is very specific. (C) 2004 Elsevier B.V. All rights reserved.