光度滴定法测定葡萄酒中的总酸

Determination of total acid in wine by photometric titration

建立光度滴定法用于葡萄酒中总酸含量的测定。试验并讨论了光度电极检测波长、取样体积及酚酞的影响,确定检测波长为640 nm,取样体积为10 mL,酚酞作为指示剂。该方法的检出限为0.07 g/L;6次平行测定值的相对标准偏差为1.15%;3个加标水平的回收率分别为94.0%、92.0%、97.0%。与国家标准规定的电位滴定法测定结果进行比对,测定结果无显著性差异。该方法操作简便,测定快速。

The photometric titration was established for determining total acid content in wine.The detection wavelength of photometric electrode,sampling volume and the effects of phenolphthalein were studied,and it was determined that the detection wavelength was 640 nm,the sampling volume was 10 mL,and phenolphthalein was used as the indicator.The detection limit of total acid was 0.07 g/L,the relative standard deviation of 6 parallel determination results was 1.15%,the recoveries of 3 spiked concentrations were 94.0%,92.0%and 97.0%.There was no significant difference between the results from this method and which from the potentiometric titration methodologies in the national standard.This method is simple,convenient and fast.