自动电位滴定法测定烟草中的无机氯

The analysis of inorganic chlorides in tobacco by automatic potentiometric method

对烟草中无机氯含量的自动电位滴定法分析的全过程进行了研究 ,确定该项分析的最佳条件为 :2g烟样 ,用 1%HNO3溶液 5 0mL浸取 5min ,然后加入 0 10 0 0mol·L- 1NaCl溶液 5 0 0mL ,固定终点电位为 15 5mV ,用AgNO3标准溶液进行自动电位滴定 .在此条件下 ,样品中Cl- 的加标回收率为 99%～ 10 1% .该方法准确度高 ,重现性好 。

The analysis of inorganic chlorides in tobacco by automatic potentiometric method was reported.The best condition of this analysis method was obtained:extracting the tobacco sample (2 g) for 5 min in 1% HNO 3 solution 50 mL and adding 0.1000 mol·L -1 NaCl solution 5.00 mL, adjusting the electric potential of end point to 155 mV,then titrating the sample solution using AgNO 3 standard solution by automatic potentiometric method.The recoveries of Cl - added to the tobacco samples were in the range of 99%～101% under this condition. It is a rapid analysis method which possesses high accuracy and precision.