Simultaneous determination of conjugated bile acids in human bile

We describe an optimized liquid chromatographic method for simultaneous analysis of 10 conjugated bile acids in gall bladder and ductal bile. A quick and effective one-step purification with Sep-pak C-18 was adopted. We used a reverse phase C18 stainless steel column and an isocratic mobile phase in a flow programme and monitored the column effluent at 205 nm. The within-day CV ranged from 0.3 to 1.8%, and the between-day CV from 1.2 to 7.2%. Absolute analytical recovery ranged from 89 to 107%. Linearity ranged from 0.3 to 3 mg/mL for most bile acids. The chromatographic analysis was completed in 18 min.