高效液相色谱法同时测定食品中9种水溶性维生素

Simultaneous determination of nine water-soluble vitamins in foods by high performance liquid chromatography

目的：建立同时测定食品中9种水溶性维生素的高效液相色谱分析方法。方法采用C18色谱柱进行分离,以pH 2.5,25 mmol/L KH2PO4-乙腈二元体系为流动相进行梯度洗脱,最后用高效液相色谱二极管阵列检测器对9种维生素进行测定。结果在优化实验条件下,测得维生素C的线性范围为0.04~100μg/mL,硫胺、核黄素、烟酰胺和吡哆醇的线性范围为0.02~100μg/mL,泛酸的线性范围为0.08~400μg/mL,生物素的线性范围为0.08~200μg/mL,叶酸的线性范围为0.01~50μg/mL,氰钴胺的线性范围为0.04~100μg/mL；线性相关系数为0.9997~0.9999,相对标准偏差为0.28%~1.35%,检出限范围为3~45 ng/mL,加标回收率为90.6%~105.4%。结论该方法快速、准确、灵敏,适合测定营养强化食品中多种水溶性维生素。

Objective To develop a high performance liquid chromatography (HPLC) method for the de-termination of nine water-soluble vitamins in foods. Methods The chromatographic separation was per-formed on a C18 column with gradient elution, using potassium dihydrogen phosphate and acetonitrile as mobile phase. The analyte was detected by HPLC with diode array detector. Results Under the optimal conditions, the calibration curves of nine vitamins were linear in the range of 0.04~100 μg/mL for vitamin C, 0.02~100μg/mL for thiamine, riboflavin, nicotinamide and pyridoxine;0.08~400μg/mL for pantothenic acid;0.08~200μg/mL for biotin; 0.01~50 μg/mL for folic acid; and 0.04~100 μg/mL for cyanocobalamin with correlation coefficient (r) more than 0.9997. The relative standard deviations (RSDs) were less than 1.35%, and the limit of detection (LOD) was found in the range of 3~45 ng/mL and the spiked recoveries were between 90.6~105.4%. The developed method was applied to determine the water-soluble vitamins in functional beverages, multivita-min tablets and fortified rice. Conclusion The proposed method is rapid, accurate and sensitive, and it is suitable for detecting water-soluble vitamins in fortified foods.