反相高效液相色谱法同时测定食品和多维片中8种水溶性维生素

Simultaneous Determination of Eight Water soluble Vitamins in Foods and Multivitamin Tablets by Reversed Phase High Performance Liquid Chromatography

建立了以0.05 mol/L KH2PO4－甲醇为流动相的梯度洗脱反相高效液相色谱同时测定水溶性维生素C、B1、B2、B6、B12、烟酸、烟酰胺和叶酸的分析方法。方法检出限为1.4～0.76ng，用该法测定了奶粉、玉米粉、饮料及复合维生素片中水溶性维生素，相对标准偏差为2.8%～8.8%;加标回收率为74.7%～112.5%。

A reversed phase high performance liquid chromatographic method for the simultaneous determination of water-soluble vitamins C, B-1, B-2, B-6, B-12, niacin, niacinamide and folic acid was developed. Gradient elution was used for the baseline separation of the eight water-soluble vitamins in 20 min. The optimized chromatographic conditions were: analytical column, Phenomenex C18 column ( 5 mum, 250 mm x 4.6 min i.d.); column temperature, ambient; mobile phase with gradient elution, 0.05 mol/L potassium dihydrogen phosphate buffer (pH 6.0)/methanol from 90/10 to 50/50 in 20 min; flow rate, 1 mL/min. Calibration graphs were linear up to 0.5 g/L for ascorbic acid and 0.1 g/L for the others. The con-elation coefficients ranged from 0.9993 to 1.000. The within- and between-day RSD were 0.7% similar to 9.6% and 1.0% similar to 9.3% (n = 7) respectively. The detection limits were 0.20 ng for ascorbic acid, 0.50 ng for niacin, 0.62 ng for VB1, 1.4 ng for VB6, 0.66 ng for niacinamide, 0.22 ng for folic acid, 0.76 ng for VB12 and 0.18 ng for VB2. The recoveries ranged from 74.7% to 112.5%. This method has been successfully applied to the determination of water-soluble vitamins in multivitamin tablets, milk powder, beverage and corn meal.