发酵液中乳酸含量测定方法比较研究

Comparative study of methods for the determination of lactic acid content in fermentation broth

为寻找高效便捷、成本低廉的乳酸测定方法,对比研究了三氯化铁法和对羟基联苯法对尾菜发酵液中乳酸含量的测定性能。结果显示,三氯化铁法和对羟基联苯法的线性方程相关系数均大于0.99,检出限分别为9.70×10^(-2)g/L和2.35×10^(-3)g/L,均满足分析测试要求;精密度测定中,三氯化铁法和对羟基联苯法的相对标准偏差(RSD)分别为1.19%~3.53%和2.54%~3.71%,加标回收率分别为99.3%~105.2%和102.7%~109.1%;杂质的存在对三氯化铁法的测定结果影响较小,但对对羟基联苯法的测定结果有较大影响;统计学检验表明,两种方法对发酵液中乳酸含量的测定结果无显著性差异;与对羟基联苯法相比,三氯化铁法操作简便,测定速度快,试剂成本低,所需样品量少,是较为优异的乳酸含量测定方法,具有广阔的应用前景。

In order to develop an efficient,convenient and low-cost method for the determination of lactic acid content,the performances of the ferric chloride method and the p-hydroxybiphenyl method were compared using the fermentation broth of vegetable residue.The results showed that the correlation coefficients of the linear equations of the ferric chloride method and the p-hydroxybiphenyl method were greater than 0.99,and the detection limits were 9.70×10^(-2)g/L and 2.35×10^(-3)g/L,respectively,which meet the requirements of analysis and testing.The rel-ative standard deviations(RSD)of the ferric chloride method and the p-hydroxybiphenyl method were 1.19%-3.53%and 2.54%-3.71%,respectively,and the recoveries were 99.3%-105.2%and 102.7%-109.1%,respectively.The presence of impurities has little effect on the results using the ferric chloride method,but has a significant influence on the results using the p-hydroxybiphenyl method.Statistical tests showed that there was no significant difference between the two methods for the determination of lactic acid content in fermentation broth.Compared with the p-hydroxybiphenyl method,the ferric chloride method has the advantages of simple operation,fast determination speed,low reagent cost,and less sample required.The ferric chloride method is an excellent method for determination of lactic acid content and has a broad development prospect.