Analysis of serum bile acids by capillary gas--liquid chromatography--mass spectrometry.

A method for quantitative analysis of serum bile acids by capillary gas--liquid chromatography--mass spectrometry is described. The main features of this method are a Grob-type barium carbonate/polyethyleneglycol 20,000 glass capillary column, an all-glass capillary interface, use of the lipophilic anion exchanger DEAP-Sephadex-LH-20 for purification of the serum extract, and chenodeoxycholic-11,12-d2 acid as internal standard. Linearity of the response (ratio of intensities of the fragment ions diagnostic for the bile acid to be measured and for the internal standard) was demonstrated for four different bile acids. The method is sufficiently sensitive for measurement of bile acids in serum of healthy humans.