Rapid Titration of Triacetin Acidity Using Electric Continuous Liquid Divider

In order to determine the acidity of triacetin efficiently, a rapid titration 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 m L of 0.02 mol/L Na OH solution was added quickly by an electric continuous liquid divider at the rate of 0.11 m L every dose repeatedly until solution's color turned pink, the total dose number of Na OH solution addition could be directly translated into triacetin acidity by a conversion table. 2) The recoveries of the method ranged from 99.3% to99.6% 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 3samples 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.