Simultaneous determination of total cholesterol concentration and radioactivity in plasma

Total plasma cholesterol concentration and radioactivity were measured simultaneously using a gas chromatograph equipped with a flame ionization detector and an effluent splitter. More than 99% of the recovered radioactivity was in the cholesterol peak. Specific activities were highly correlated with the amounts of labeled cholesterol present in plasma. The recovery of label was quantitative over a wide range of carrier cholesterol concentrations. The method is highly reproducible, accurate, rapid and specific.