中性甲醛浸提-电导滴定法快速测定食醋的总酸度  

The Rapid Determination of Total Acidity of Vinegar by Neutral Formaldehyde Extraction with Conductivity Titration

作　　者：高向阳[1,2] 朱盈蕊[3] 高遒竹 王长青[2] 马帅[1] 

机构地区：[1]郑州科技学院食品科学与工程系,郑州450064 [2]河南农业大学食品科学技术学院,郑州450002 [3]郑州市质量技术监督检验测试中心,郑州450006 [4]江南大学食品学院,江苏无锡214122

出　　处：《中国调味品》2015年第11期89-92,共4页China Condiment

基　　金：河南省科技攻关项目(JBO2 0624430003)

摘　　要：为建立一种测定食醋中总酸度的新型分析方法,用中性甲醛溶液将食醋中的弱酸完全转化为强酸,在单因素试验的基础上通过正交试验优化最佳条件。根据电导滴定法中消耗的标准溶液的物质的量,用单位体积样品中相当的等物质量的氢离子为统一计算标准,同时与国标方法比较进行平行测定。结果表明:恒顺陈醋的总酸度(H+)为1.217mol/L,相对标准偏差RSD为0.94%,上海白醋的总酸度(H+)为1.207mol/L,RSD为0.57%,恒顺9°米醋的总酸度(H+)为1.238mol/L,RSD为0.78%,紫林陈醋的总酸度(H+)为1.222mol/L,RSD为0.45%。与国标法对照,测定结果经F检验表明无显著性差异,经t检验表明有显著性差异,结论的置信度为95%。该法具有操作简单,快速方便,试剂用量少,无需使用指示剂等优点,是一种更为科学合理、更加符合样品实际的新型分析方法,测定结果令人满意。In order to explore a new method for the determination of total acidity in vinegar.Use neutral formaldehyde solution to convert weak acid completely into strong acid.Use single factor experiment and orthogonal experiment to determine the optimum experimental conditions.Under the most suitable conditions,according to the amount of substance of standard solution consumed in conductivity titration,with equivalent-quantity hydrogen ions in per unit volume of sample as unified calculation standard, the results compared with the national standard method are for parallel determination.The results show that：the total acidity of Hengshun vinegar （H^＋）is 1.217 mol/L, the relative standard deviation of RSD is 0.94%,the total acidity of Shanghai vinegar （H^＋）is 1.207 mol/L,RSD is 0.57%,the total acidity of rice vinegar （H^＋）is 1.238 mol/L,RSD is 0.78%, the total acidity Zilin vinegar （H^＋）is 1.222 mol/L,RSD is 0.45%,comparing the determination results of two methods by F test ,there＇s no significant difference ,and the t test shows that there＇s significant difference.The credibility of the conclusion is 95%.The method has many advanta-ges,such as simplicity of operator,speediness,convenience and less reagent dosage,no use of indicator,less pollution and so on.It is a new analysis method which is more scientific and rea-sonable,practical,used for the determination of specific samples,with satisfactory results.

关 键 词：中性甲醛溶液 电导滴定 食醋 总酸度 

分 类 号：TS264.22[轻工技术与工程—发酵工程]