Journal of Lipid Research, Vol 38, 1906-1912, Copyright © 1997 by Lipid Research, Inc.
Bile acid analysis in biological fluids: a novel approach
K Budai and NB Javitt
Division of Hepatic Diseases, New York University Medical Center, NY 10016, USA.
In contrast to current methods of bile acid analysis that require the
separation of bile acids into different groups prior to their analysis, the
HPLC method using a reverse phase column and gradient elution that we
developed permits the separation and detection of nonconjugated,
glycine-conjugated, and esterified bile acids as their fluorescent
dimethoxycoumarin esters. The mild conditions for ester formation make
possible the identification of allylic bile acids characteristic of
metabolic errors in bile acid synthesis. Quantification is obtained using 7
alpha,12 alpha-dihydroxy-5 beta-cholanoic acid as an internal standard. In
addition to identification based on retention time, peak- shift strategy is
used by treatment of aliquots with cholyglycine hydrolase and/or
solvolysis. Loss of the parent peak and appearance of the derivative
provide further assurance of the identity of each bile acid in biologic
fluids that contain other organic acids.