REVERSED-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY DETERMINATION OF QUININE IN PLASMA, WHOLE-BLOOD, URINE, AND SAMPLES DRIED ON FILTER-PAPER

The analysis of quinine in whole blood, plasma, urine, and samples dried on filter paper is described. Extraction was made with toluene followed by back-extraction into phosphate buffer. A reversed-phase liquid chromatography system with fluorescence detection was used. The within-day coefficient of variation of the method was 4-10% at the lower limit of determination (2 nM in plasma and 50 nM in whole blood, dried samples, and urine) and 2-4% at 10 muM. The quinine concentration was found to be lower in whole blood than in plasma (mean ratio, plasma-whole blood, 1. 17). The concentration in capillary blood was lower than that in venous blood (mean ratio, capillary blood-venous blood, 0.93).