Simultaneous analysis of water-soluble and fat-soluble vitamins through RP-HPLC/DAD in food supplements and brewer?s yeast

The current study is focused on investigation and quantitation of seven commercially available on the Bulgarian market food supplements, containing multivitamin mixtures of water-soluble and fat-soluble vitamins. In addition, a second fermentation brewer's yeast is also analyzed. The analytical procedures are performed on a RP-HPLC/DAD using Purospher STAR C18 (Merck Millipore, Germany) 5 mu m, 25 x 0.46 cm column, conditioned at 25 degrees C in a column oven. Dionex UltiMate 3000 high performance liquid chromatograph was carried out in diode array detector, set up at 270 nm for water-soluble vitamins, except for vitamin B5, where 210 nm was applied as analytical wavelength. The fat-soluble vitamins were detected at 325 nm and 265 nm for vitamin A and vitamin E, respectively. Two general methods were developed where Method 1 was based on gradient elution and Method 2 was based on isocratic elution. Both methods identified stated by the manufacturer labeled amounts. The developed methods are applicable for routine analysis of vitamin contents both in multivitamin preparations and in brewer's yeast from secondary fermentation.

Automated summary

The current study focused on investigating and quantifying seven commercially available food supplements in the Bulgarian market, which contained a mixture of water-soluble and fat-soluble vitamins. Additionally, brewer's yeast from secondary fermentation was also analyzed. The analytical procedures were performed using RP-HPLC/DAD with specific columns and wavelengths for different vitamins. Two methods, gradient elution and isocratic elution, were developed and both were able to confirm the labeled amounts of vitamins as stated by the manufacturer. These methods are applicable for routine analysis of vitamin contents in both multivitamin preparations and brewer's yeast.