Quantitation method for choline-containing phospholipids in human serum lipoproteins by high performance liquid chromatography.

A determination method for choline-containing phospholipids in serum lipoproteins was established by application of the HPLC method [Hara et al. (1980) J. Biochem. 87, 1863-1865; (1981) 89, 879-887] developed for cholesterol quantitation. The concentration of choline-containing phospholipids in the fraction separated by HPLC using gel permeation columns was determined through colorimetric detection using a commercial enzymatic kit. The optimum conditions for enzymatic reaction in the flow diagram were examined. The concentration calculated from the A500 peak area was found to reflect very precisely the concentration of choline-containing phospholipids in all lipoprotein fractions, and the quantitation of each lipoprotein fraction can be performed with only 10-20 microliters of whole serum. Monitoring the elution patterns by detecting choline-containing phospholipids can give much more information about lipoprotein distributions according to particle size than analyses done by detecting cholesterol.