31P-NMR assay of phosphatidylcholine and phosphatidylethanolamine in AL721

A 31P-NMR based method has been developed for the assay of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) in AL721. The assay is based on the comparison of NMR signal intensities of the phosphatidyl moiety of PC and PE to the signal of triphenylphosphate (TPP), the internal standard. The assay is specific and reliable for the quantitation of phospholipid mixtures. Its uncertainty, due primarily to low intensity of 31P signals, was estimated at less than 6%.