Sensitive analysis of ethanolamine- and serine-containing phosphoglycerides by high-performance liquid chromatography

A highly sensitive method for the separation and quantitative measurement of phospholipids containing primary amino groups, such as phosphatidylethanolamine, phosphatidylserine and lysophosphatidylethanolamine, is described. The method involves a simple and quantitative derivative formation of the phospholipids containing amino groups to their u.v.-absorbing biphenylcarbonyl derivatives. These have molar extinction coefficients of about 23,000 at 268nm. The phospholipid derivatives are then separated and non-destructively determined by high-performance liquid chromatography. The amino phospholipids containing vinyl ether bonds (plasmalogens) can be determined separately from the diacyl- and alkylacyl-amino phospholipids. The lower limit of detection by high-performance liquid-chromatographic analysis of the phospholipid derivatives is about 10-13pmol or 0.3-0.4ng of phospholipid P. The quantitative range of derivative formation and analysis by high-performance liquid chromatography of the phospholipids containing amino groups was shown to be 10-500nmol. The method was shown to be applicable to the analysis of phospholipids containing amino groups in tissue samples.