两点法用于卷烟纸灰分滴定终点的确定

Finding Out End Point in Titration for Determining Ash Content in Cigarette Paper with Two-point Method

为了快速测定卷烟纸灰分,考察了两点法用于确定卷烟纸灰分滴定终点的准确性和精密性,采用两点法、绘图法、指示剂法和高温法分别检测了7个卷烟纸样品的灰分,并对检测结果进行了F检验和t检验。结果表明:①计量点前、后的两点法回收率分别为100.5%～100.8%和100.0%～100.7%,相对标准偏差分别为0.38%～0.80%和0.61%～0.82%;②置信度为95%,任意两方法相比,精密度均无差异;计量点前、后两点法之间及其与绘图法相比均值无显著差异,但与指示剂法、高温法相比均值有显著差异。两点法确定滴定终点的电位滴定法可用于批量卷烟纸灰分的快速分析。

In order to determine the ash content in cigarette paper rapidly, the accuracy and precision of end point in titration determined with two-point method were studied. The ash contents in seven cigarette paper samples were determined by two-point, graphic, indicator, and high temperature methods, respectively. The data obtained were compared by F test and t test. The results showed that： 1） the recoveries, the readings of the points before and after equilibrium point, of the two-point method ranged from 100.5% to 100.8% and from 100.0% to 100.7% with the RSDs of 0.38% to 0.80% and 0.61% to 0. 82%, respectively; 2） at the confidence level of 95% , there was no significant difference between the precision values of the said methods and no significant differences between the average values of two-point method and graphic method, while there was significant difference between the average values of two-point method and indicator or high temperature methods. In potentiometric titration, determining end point by two-point method is fit for the rapid analysis of ash content in batches of cigarette paper samples.