Abstract
A method by liquid chromatography/atmospheric pressure chemical ionization tandem mass spectrometry (LC/APCI-MS/MS) for the quantitative determination of pravastatin and its main metabolite (R-416) in human plasma with a fully automated on-line solid-phase extraction (SPE) system, PROSPEKT-2TM was established. The method employed the direct on-line injection of human plasma into the PROSPEKT-2TM system for extraction of the analytes followed by column switching introduction of analytes to the LC/APCI-MS/MS system. The use of on-line SPE system resulted in reducing the sample preparation time and decreasing endogenous interfering substances in the extracts. The lower limit of quantification (LLOQ) for the assay was 0.1 ng/mL for pravastatin and R-416 on a 100 μL plasma sample. The calibration curves were linear for concentrations ranging from 0.1 to 100 ng/mL for both analytes. The intra- and inter-assay precisions were less than 4%. The method provides an automated sample analysis in a total cycle time of 6 min, allowing the analysis of many plasma samples to be conducted with increased throughput and improved robustness.
