双波长分光光度法同时测定食品中VC、VE方法研究_食品科学与工程.rar

摘要:本实验提出了一种同时测定食品中维生素C和维生素E的新方法。以无水乙醇为参比溶液，配制0.0072mg/mL维生素C标准溶液和0.005mg/mL维生素C标准溶液测定最大吸收波长分别为270nm、291nm。通过单因素和正交试验确定溶液pH、放置时间、反应温度、光照时间、活性炭用量、容量瓶选择对本实验的影响。实验结果表明，维生素C受因素的影响很大，而维生素E性质相对稳定，受各因素的影响较小，所以选择在维生素C最佳测定条件下测定两种物质。选择溶液pH为7，温度为20℃，活性炭0.001g，在避光条件下，用棕色容量瓶为最佳试验条件，对实际样品进行测定。用紫外可见分光光度法，其检出限为0.00381mg/L。在最佳条件下对样品测定，维生素C的相对标准偏差为1.457%~4.663%，加标回收率在95.11%～100.16%之间，其测定结果与国标测定结果相比较，相对误差在4.134%~14.045%之间，结果基本一致；维生素E的相对标准偏差为2.016%~5.551%，加标回收率在92.06%～106.89%之间，其测定结果与国标测定结果相比较，相对误差在6.060%~11.765%之间，结果基本一致。

　　　此方法简单、准确、快捷，可作为同时检测食品中维生素C和维生素E的一种新方法。

关键词 双波长法；维生素C；维生素E

Abstract:This paper proposed a new method for simultaneous determination of Vitamin C and Vitamin E in food. For Vitamin C and Vitamin E can soluble in ethanol at the same time, anhydrous ethanol as a solvent, and the absorbance plus and nature, Vitamin C and Vitamin E absorption in the UV-visible region of the nature of the curve, select the two substances wavelength, the standard curve, solve simultaneous equations can be directly measured Vitamin C and Vitamin E content in the sample. Through single factor and orthogonal experiments to determine the pH of the solution, storage time, reaction temperature, illumination time, the dosage of activated carbon, volumetric flask select the experiment. The experimental results show that the factors of Vitamin C, Vitamin E is relatively stable nature, less affected by various factors, so the two substances selected in the measured Vitamin C under optimum conditions. Select the solution pH 7, temperature 20℃, activated carbon 0.001g, in dark conditions, with brown volumetric flask is the best test conditions, the sample analysis.UV-visible spectrophotometry, the detection limit is 0.0381mg/L. The determination of the sample under optimal conditions, Vitamin C and the relative standard deviation is 1.457% to 4.663%, and the recovery between 95.11% to 100.16%, the measurement results of the measurement results of the GB, the relative error is 4.134% to 14.045%, the results are basically the same;Vitamin E relative standard deviation is 2.016% to 5.551%, and the recovery in the range of 92.06% to 106.89%, the measurement results of the measurement results of the GB, the relative error between 6.060 % and 11.765%, the results are basically the same.

This method is simple, accurate, fast, and can be used as a new method of simultaneous detection of Vitamin C and Vitamin E in food.

Keywords  Dual-wavelength method  Vitamin C  Vitamin E