High-performance liquid chromatographic separation of vitamin D3 3-fatty acid esters and their liquid chromatography mass spectrometry

The separation of authentic vitamin D-3 3-stearate, -palmitate, oleate, and -linoleate, possible metabolites of vitamin D3, was carried out using reversed-phase high performance liquid chromatography. Liquid chromatography/atmospheric pressure chemical ionization - mass spectrometry (LC/APCI-MS) of these esters was also examined, and a deesterified peak was detected as a base peak. On the contrary, the fatty acid ester derivatized with a Cookson-type reagent, 4-phenyl-1,2,4-triazoline-3,5-dione, showed a quasi-molecular ion as an intense peak. The LC/APCI-MS data on the adducts of another Cookson-type reagent having an electron-capture substituent were also reported.