SIMPLE AND SENSITIVE REVERSED-PHASE LIQUID-CHROMATOGRAPHIC ASSAY FOR ANALYSIS OF CHLORTHALIDONE IN URINE

This study describes a rapid method for the determination of chlorthal idone in human urine by reversed-phase liquid chromatography and UV de tection at 230 nm, after clean-up over a C8 solid-phase extraction col umn. Liquid chromatography was carried out on a C18-bonded phase using acetonitrile-phosphate buffer (pH=3) gradient elution. Triamterene wa s used as internal standard. The system has been applied to the determ ination of chlorthalidone in the 0.10-10.0 mug/mL concentration interv al; the limit of detection was 6 ng/mL.