重氮化反应光度法测定烟丝中硝酸盐  

PHOTOMETRIC DETERMINATION OF NITRATE NITROGEN IN CUT TOBACCO

作　　者：夏炳乐[1] 刘少民[1] 戴亚[1] 刘清亮[1] 李敏莉[2] 

机构地区：[1]中国科学技术大学食品科学系,合肥230052 [2]合肥卷烟厂技术中心

出　　处：《理化检验（化学分册）》2003年第11期669-671,共3页Physical Testing and Chemical Analysis(Part B:Chemical Analysis)

基　　金：国家烟草专卖局科研基金资助 (NO :0 0 2 0 0 10 10 41)

摘　　要：采用乙酸溶液提取烟丝中的NO- 3,锌粉作还原剂 ,萘基乙二胺 (二盐酸化盐 )及对氨基苯磺酸作显色剂 ,建立了一种测定烟草中硝酸盐的光度法。该法简便、灵敏、准确 ,线性范围为 0 .1～ 0 .6 μg·ml- 1(NO- 3 N) ,平均回收率为 97.5 % ,RSD为 2 .6 %～ 3.8%。Nitrate in the cut tobacco sample was extracted with acetic acid (1+99), reduced to nitrite with zinc powder. Finally, nitrate nitrogen (in the form of NO - 2) was determined through a diazotisation reaction among NO - 2, naphthyl ethylene diamine and sulfanilic acid in a dilute acetic acid medium, forming a red colored azo compound ( λ max 540nm). The absorbance of the red azo compound produced was found to be directly proportional to amounts of NO - 2 present. Linear relationship holds in the range of 0.1 to 0.6μg of nitrate nitrogen per ml of solution. Results obtained in the analysis of 8 kinds of cut tobacco gave RSD′s in the range of 2.6% to 3.8%. Recoveries were in the range of 97.2% to 99.8%. The results were checked by GC method, and showed good consistency.

关 键 词：重氮化反应 吸光光度法 烟丝 硝酸盐 锌粉 显色剂 

分 类 号：TS411[农业科学—烟草工业] O657.31[理学—分析化学]