Studies On The Analysis Method Of Water-Soluble Vitamins In Food

Water-soluble Vitamins, as a part of vitamins, play an important role in human body. With the sorts of food enriched vitamins improving, simultaneous determination of vitamins in food is definitely meaningful.In this paper, on the background of lack of analysis method for vitamins in food, especially in baby milk powder, an analysis method for vitamins in beverage, multivitamin tablets and baby milk powder was investigated systematically and established by LC-UVD and LC-MS.In this paper, the method of how to prepare every vitamin standard solution was studied. From the stability test, the stability of every vitamin standard solution was found, and then the method to prepare Vc standard solution was optimized.The pretreatment method of milk powder sample, as the most complicated sample in the enriched vitamins food, was discussed. On the basis of equipotential method, every pH was optimized. Average recoveries obtained by this optimized pretreatment ranged from 97.8% to 103.8%, and the relative standard deviation (RSD) valued from 0.2% to 2.7%.In this paper, the conditions of HPLC-UVD for simultaneous detection of eight Water-soluble Vitamins were optimized. Under the conditions, eight Water-soluble Vitamins could be separated completely. RSD ranged from 0.2% to 2.3%. The limits of detection for the method valued from 0.007 to 0.035 mg/L.In this paper, the conditions of HPLC-MS for simultaneous detection of nine Water-soluble Vitamins and Taurine were studied and optimized. Under those conditions, ten substances could be separated definitely. RSD ranged from 0.3% to 1.9%. The limits of detection for the method valued from 0.002 to 0.036 mg/L.The pretreatment and detection methods were applied to analyse 3 kinds of beverages, 1 kind of multivitamin tablets and 4 kinds of baby milk powders. The results show that some vitamins in food fall short of label. The task of detecting vitamins in food is necessary.Finally, recovery tests and RSD were detected to prove that the established pretreatment method and two detecting methods are accurate. Using HPLC-UVD, average recoveries obtained ranged from 97.3% to 104.8%, and the relative standard deviation (RSD) ranged from 0.2% to 2.3%. While using HPLC-MS, average recoveries obtained ranged from 97.2% to 101.6%, and the relative standard deviation (RSD) ranged from 0.3% to 1.9%. The results show that the proposed methods match the requirement of analysis, have highly reliability and could be applied to Simultaneous Determination of multi-vitamins in food. The method using HPLC-MS is more satisfactory relatively.