Semi-automated high-performance liquid chromatographic method for the determination of cyclosporine in plasma and blood using column switching
Smith, H.T.; Robinson, W.T.
Journal of Chromatography 305(2): 353-362
ISSN/ISBN: 0021-9673 PMID: 6707163 Accession: 006386970
A sensitive, semi-automated high-performance liquid chromatographic method using column switching is described for the determination of cyclosporin [an immunosuppressant] in plasma and blood. This method involves a short and improved manual protein precipitation of the sample followed by an automated clean-up of the supernatant. After automatic loading of the clean supernatant onto an LC-8 column for initial separation, the segment containing cyclosporin is loaded (automatically) onto on LC-18 column for final separation and quantitation. Cyclosporin is detected by its UV absorption at 202 nm. The rate of analysis was 4 samples/h running 24 h/day (.apprx. 100 samples/day). The method is sensitive enough to measure with confidence cyclosporin concentrations of 8 .mu.g/l in plasma and 20 .mu.g/l in blood with a linear response up to 2500 .mu.g/l using only 0.5 ml of sample. No internal standard is required. The method was applied continuously (24 h/day) to approximately 1000 samples without deterioration in method parameters.