自动电位滴定法测定烟用香精香料的酸值

为解决采用滴定法测定烟用香精香料酸值时滴定液的配制过程复杂、稳定性不高,以及样品的检测时间长、通量较低等问题,建立了一种测定烟用香精香料酸值的自动电位滴定分析方法。以低、中、高3个梯度酸值的19个烟用香精香料样品为研究对象,采用该方法和行业标准方法进行测定,并对测定结果进行两配对样本T检验。同时,测定了151种烟用香精香料样品。结果表明:①优化确定的条件为:以0.1 mol/L氢氧化钾标准溶液为滴定液,用40 mL 41.7%乙醇溶解样品,样品量为0.8~1.0 g。②方法的相对标准偏差为0.5%~2.3%(n=6),重复性较好。③两种分析方法的测试结果之间不存在显著差异,方法的准确性较好。④151个实际样品检测结果的极差为0.00~0.60,满足行业标准对平行样的测定要求,表明方法的实用性较强。该方法简便、快速、准确,适合于烟草企业大批量、多牌号烟用香精香料酸值的测定。

Determination of acidic values of tobacco flavor ingredients by automatic potentiometric titration

Current method to determine acidic value of tobacco flavor ingredients by titration method is complex preparing titration solutions,low stability,long detection time and low sample throughput.An automatic potentiometric titration analysis method was established.Nineteen tobacco flavors with low,medium and high gradient acidic values were used as test samples,and their acidic values were determined using the established method and compared to those obtained by the industry standard method.The results were compared by two-pair T test method.In addition,acidic values of 151 tobacco flavors of different brands were determined.The results showed that:1)The optimized parameters were using 0.1 mol/L potassium hydroxide standard solution as the titrant,with 0.8-1.0 g test material dissolved in 41.7%ethanol at 40 mL.2)The relative standard deviation(RSD)of the established method was 0.5%-2.3%(n=6),and the repeatability was improved.3)There was no significant difference between the test results obtained by the two methods,and the accuracy of the established method was better.4)The range of test results for the 151 samples was 0.00-0.60,which met the requirements of industry standard for parallel measurement,indicating that the method was practical.The method is simple,rapid,accurate,and suitable for determining the acidic values of tobacco flavors of large scale and multi-brand of tobacco products.