摘要
对白酒中总酸含量测定的不确定度进行分析。以酚酞为指示剂,氢氧化钠标准滴定溶液为滴定剂,采用重复性试验,用消耗氢氧化钠标准滴定溶液的量计算白酒中总酸的含量,并通过数学模型的建立,分析测量不确定度的来源,并量化各个不确定度分量,最终合成不确定度,评价酸碱滴定法测定白酒中总酸的扩展不确定度。结果表明,本方法检测总酸的合成标准不确定度为0.0059 g/L,取置信概率95%的扩展不确定度为0.012 g/L。白酒试样中总酸的的测量结果为:y=(0.896±0.012)g/L,k=2。通过不确定度评定分析可知白酒中总酸测定的不确定度主要由标准溶液、样品处理过程中的标准曲线的建立及样品加标回收引起。本研究为酸碱滴定法测定白酒中总酸的含量及不确定度评价提供了参考。
The uncertainties in the determination of the total acids in Baijiu were analyzed.With phenolphthalein as the indicator and sodium hydroxide standard solution as the titrant,the content of total acids in Baijiu was calculated by using the amount of sodium hydroxide standard solution consumed in the repeatability tests.The sources of the uncertainties were analyzed through mathematical model,and each uncertainty component was quantified.Finally,the expanded uncertainty of the acid-base titration method in the determination of total acids in Baijiu was evaluated.The results showed that the standard uncertainty of the method was 0.0059 g/L,and the expanded uncertainty of 95%confidence probability was 0.012 g/L.The total acids in Baijiu was y=(0.896±0.012)g/L,k=2.It was found that the uncertainties in the determination of total acids in Baijiu were mainly caused by the establishment of standard curve in the process of sample treatment and the recovery of spiked sample.This study has provided reference for the determination of total acids in Baijiu by acid-base titration method and the evaluation of the uncertainties.
作者
陈媛媛
赵光远
CHEN Yuanyuan;ZHAO Guangyuan(Baotou Food and Drug Inspection&Testing Center,Baotou,Inner Mongolia 014060,China)
出处
《酿酒科技》
2020年第11期110-113,共4页
Liquor-Making Science & Technology
关键词
不确定度
白酒
总酸
酸碱滴定
uncertainty
Baijiu
total acids
acid-base titration
