A method for simultaneous quantification of phospholipid species by routine 31P NMR

We report a (31)P NMR assay for quantification of aqueous phospholipid samples. Using a capillary with trimethylphosphate as internal standard, the limit of quantification is 1.30 mM. Comparison of the (31)P NMR quantification method in aqueous buffer and in organic solvent revealed that the two methods are equal within experimental error. Changing the pH of the buffer enables peak separation for different phospholipid species. This is an advantage compared to the commercial enzyme assay based on phospholipase D and choline oxidase. The reported method, using routine (31)P NMR equipment, is suitable when fast results of a limited number of samples are requested.