IMPROVED HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC DETERMINATION OF DEBRISOQUINE AND 4-HYDROXYDEBRISOQUINE IN HUMAN URINE FOLLOWING DIRECT-INJECTION

A sensitive and specific reversed-phase high-performance liquid chroma tographic assay was developed for the determination of debrisoquine an d 4-hydroxydebrisoquine in urine. The urine samples were directly inje cted following an ether clean-up step which eliminated interference. S eparation of the analytes was achieved using a mobile phase consisting of acetonitrile-methanol-0.02 M heptane sulfonic acid (pH 3.0) (6:37: 57) and a mu Bondapak C-18 analytical column. The assay utilizes fluor escence detection at 208 nm (ex) and 562 (em). The within-day and betw een-day coefficients of variation were less than or equal to 10% for b oth components and accuracy was within 12%. The method is suitable for pharmacogenetic studies utilizing debrisoquine.