自动凯氏定氮仪测定烟草及其制品中的总氮

摘要

The influences of amount of digesting agents, including CuSO4, K2SO4, and concentrated H2SO4, on the results in determining total nitrogen content in tobacco and tobacco product were investigated.The total nitrogen content in the samples was determined by an automatic steam distillation and titration device ( automatic Kjeldahl nitrogen analyzer).The results showed that the average recoveries of nitrogen ranged from 97.90％ to 103.85％ with the coefficient of variation below 2％ when the sample was digested by 0.4 g CuSO4, 6.0 g K2SO4, and 12 mL concentrated H2SO4.There is no significant difference between the test results of the mentioned method and YC/T161-2002 standard method.The proposed method is suitable to the rapid analysis of total nitrogen in tobacco and tobacco products.%为了替代烟草及其制品中总氮含量测定过程中使用的有毒消解剂氧化汞,考察了消解剂用量对烟草及其制品中总氮含量测定结果的影响,并采用自动水蒸气蒸馏滴定仪测定样品中的总氮含量.结果表明,用硫酸铜替代氧化汞,当用0.4 g硫酸铜、6.0 g硫酸钾和12 mL浓硫酸消解烟草样品时,总氮含量测试变异系数小于2%,回收率在97.90%～103.85%之问.该法的测试结果与YC/T161-2002规定的方法无显著性差异.该法适合烟草及其制品中总氮含量的快速分析.