容量滴定法测定味精中谷氨酸钠含量的研究

采用标准试剂合成味精试样,对GB/T5009.43-1996酸度计法测定味精中谷氨酸钠含量进行了研究。结果表明,其滴定终点控制在pH9.40～9.60或9.80～10.00时,测定结果与旋光法及理论值有明显差异;当滴定终点控制在pH9.67时,与后二者结果一致,最佳终点pH值为9.67。对味精中其它添加物呈味核苷酸钠、蔗糖及淀粉的干扰情况也作了进一步实验摸索。

Determination of Monosodium L-Glutamate by Volumetry

Monosodium L-glutamate was determined by acidimetery according to GB/T 5009.43-1996. The results of determination were significantly different from the results of polarimetry and the theoretical values when the end point of titration was controlled of pH9.40~9.60 or 9.80~10.00, but they were consistent with the latter two when the end point of titration was controlled at pH9.67. The optimum end point pH value should be 9.67. The influence of additives such as 5′-nucleotide, cane sugar and starch on the result of acidimetry was also studied.