IDENTIFICATION OF VITAMIN-A, VITAMIN-D AND VITAMIN-E BY PARTICLE-BEAM LIQUID-CHROMATOGRAPHY MASS-SPECTROMETRY

Particle beam (PB) high performance liquid chromatography (HPLC)-mass spectrometry (MS) has been studied to investigate its suitability for the analysis of fat-soluble vitamins, as an example of thermally labile substances. The PB LC-MS system has been used to detect and identify vitamins A, D and E in foods and multi-vitamin preparations. The qualitative performance of the PB interface has been evaluated by an examination of the working parameters. A rapid elution of the vitamins was obtained on a C8 reversed-phase column using an aqueous methanol mobile phase. Analyses have been carried out using both, electron (EI) and chemical(CI) ionization. Positive and negative-ion CI spectra of the compounds are discussed. When PB-MS conditions are optimized, the detection limits for the fat-soluble vitamins tested have been typically in the 0.6-25 ng range when using the selected-ion monitoring technique.