High throughput assay method for the quantitation of trimetazidine in human plasma by LC/MS, with selected reaction monitoring

Following oral ingestion (40mg), trimetazidine was quantified in human plas ma, using selected reaction monitoring (SRM). The simplicity of the liquid- liquid extraction procedure, together with the sensitivity and specificity afforded by LC-MS/MS, resulted in a highly sensitive and robust assay metho d in which 200-250 samples were processed per day. Extraction from plasma into hexane/dichloromethane (1+1) and acetylation wi th acetic anhydride in the organic phase was followed by a novel back-extra ction into water and in situ generated acetic acid. This acetylation proced ure was found to be necessary to overcome significant carry-over problems e ncountered with the underivatised analyte. Separation was achieved on a Phe noexo(R) Luna C-8 reversed phase column and detection by tandem mass. spect rometry, with a sample tam-around time of 3 minutes.