Determination of phylloquinone (vitamin K 1) by high performance liquid chromatography with UV detection and with particle beam-mass spectrometry

A reversed-phase PB LC-MS method was used for the determination and unequivocal identification of vitamin K₁ in some vegetable samples. The method was also applied to the identification of other constituents in the food analyzed. LC-MS experiments were carried out in both EI and negative-ion CI modes. Preliminary sensitivity studies on vitamin K₁ showed a detection limit of 2 ng (signal-to-noise ratio=3) in negative-ion operation and in single-ion monitoring at m/z 450. Quantitative results obtained with LC-MS for the extracts of four vegetables were compared with those of LC-UV analyses performed at 247 nm.