凯氏定氮法测定铝灰中氮化铝

Determination of aluminum nitride in aluminum ash by Kjeldahl method

建立凯氏定氮法测定铝灰中氮化铝的方法。用碱液与铝灰反应,使锥形瓶产生的氨气经过冷凝,用硼酸溶液吸收其中产生的氨气,用氨基磺酸标准溶液进行滴定,根据氨基磺酸消耗的量计算出氮元素的质量分数,进而计算出氮化铝含量。按照实验方法测定3个铝灰实际样品中氮化铝含量,测定结果的相对标准偏差为0.53%~1.22%(n=9),加标回收率为98%~103%,该方法操作简单、准确、高效,可以满足铝灰中氮化铝含量的准确测定。

A method for determination of aluminum nitride in aluminum ash by Kjeldahl method was established.The alkali liquor was reacted with aluminum ash,after the resulting ammonia gas condensesed,ammonia was absorbed with a solution of boric acid.Titrate with sulfamic acid standard solution,the mass fraction of nitrogen was calculated according to the amount of sulfamic acid consumed,and then the aluminum nitride content was calculated.According to the experimental method,the content of aluminum nitride in three aluminum ash samples was determined,the relative standard deviation of the method was less than 2%(n=9),the standard addition recovery was 98%-103%.This method is proved with standard recovery test and precision test to be simple,accurate,high-efficient and suitable to fast analysis.