DETERMINATION OF CRITICAL MICELLE CONCENTRATION OF BILE-ACID SALTS BYMICRO-CALORIMETRIC TITRATION

Critical micelle concentrations (CMC) of sodium salts of cholic, deoxy cholic and chenodeoxycholic acids in phosphate buffer (pH 7.92) have b een determined from microcalorimetric titration curves. The obtained v alues of 18.4+/-0.6, 5.3+/-0.2 and 7.0+/-0.2 mM, respectively, for Na cholate, Na deoxycholate and Na chenodeoxycholate are close to literat ure values obtained by other methods. CMC values for 'secondary' micel les were also obtained. This microcalorimetric titration method gives highly reproducible results and rapid determination of CMC values of b ile acid salts.