三乙酸甘油酯酸度的电动连续分液器快速滴定

Rapid Titration of Triacetin Acidity Using Electric Continuous Liquid Divider

为提高烟用三乙酸甘油酯酸度的检测效率,建立了一种三乙酸甘油酯酸度的快速滴定方法,并采用该方法测定了10个国内外烟用三乙酸甘油酯样品的酸度。结果表明：1优化确定的滴定条件为：烟用三乙酸甘油酯样品用无水乙醇稀释并加入酚酞指示剂后,用电动连续分液器快速添加0.02 mol/L Na OH溶液,每次添加0.11 m L,至显粉红色时记录加液次数,由三乙酸甘油酯酸度值与Na OH加液次数的对照表直接读出酸度值。2该方法的回收率为99.3%-99.6%,相对标准偏差（RSD）小于7%。3所测的10个样品中,有7个样品的酸度检测结果小于0.010%,在限量值以内;有3个样品的酸度检测结果大于0.010%,超过限量值,其中2个样品的酸度大于0.020%。该方法操作简便快速、数据准确,适合用于三乙酸甘油酯样品的酸度测定。

In order to determine the acidity of triacetin efficiently, a rapid tltratmn method was developed with electric continuous liquid divider, and the acidity of 10 domestic and imported triacetin samples was determined. The results showed that： 1） The optimized procedure was as follows： triacetin sample was diluted by anhydrous ethanol, phenolphthalein was added as an indicator, then 0.11 mL of 0.02 mol/L NaOH solution was added quickly by an electric continuous liquid divider at the rate of 0.11 mL every dose repeatedly until solution＇ s color turned pink, the total dose number of NaOH solution addition could be directly translated into triacetin acidity by a conversion table. 2） The recoveries of the method ranged from 99.3% to 99.6% with the relative standard deviations （RSDs） less than 7%. 3） Among the 10 tested samples, the acidity of 7 samples was below the restrictive value of 0.010%, and that of 3 samples was above the value, in which the acidity of 2 samples was more than 0,020%. This method is simple, fast, accurate, and suitable for determining the acidity of triacetin for cigarette.