常量法测定螺旋藻片中氮含量的不确定度评定

Uncertainty evaluation for the determination of nitrogen content in Spirulina tablets by constant method

中文关键词:  螺旋藻片  氮含量  不确定度  常量法

英文关键词:Spirulina tablet  nitrogen content  uncertainty  constant method

中文摘要:

      目的 评定常量法测定螺旋藻片中氮含量的不确定度。方法 采用《中国药典》2015年版第四部氮测定法中第一法(常量法), 测定螺旋藻片中的含氮量, 通过获得的检测数据, 评定测定螺旋藻片中氮含量的不确定度。结果 当氮含量的结果为20.59 mg/片时, 常量法测定螺旋藻片氮含量的合成标准不确定度为0.197 mg/片, 扩展不确定度为0.39 mg/片, 螺旋藻片中氮含量测定的结果为(20.59±0.39) mg/片, (k=2, P=95%)。结论 测量不确定度主要来源于试样测定重复性实验、硫酸标准溶液的标定、滴定过程、试样的消化及蒸馏; 试样称量引入的不确定度贡献较小。

英文摘要:

      Objective To evaluate the uncertainty for the determination of nitrogen content in Spirulina tablets by constant method. Methods The first method (constant method) in the fourth nitrogen determination method of the Chinese pharmacopoeia 2015 edition was used to determine the nitrogen content in Spirulina tablets. The uncertainty of determination of nitrogen content in spirulina tablets was evaluated through the obtained test data. Results When the nitrogen content was 20.59 mg/tablet, the standard uncertainty for the determination of nitrogen content in Spirulina tablets by constant method was 0.197 mg/ tablet, the extended uncertainty was 0.39 mg/tablet, and the determination result of nitrogen content in Spirulina tablets was (20.59±0.39) mg/tablet (k=2, P=95%). Conclusion The uncertainties of measurement mainly come from the repeatability experiment of sample determination, sulfuric acid standard solution, titration process, digestion and distillation of sample, and the uncertainty contribution of sample weighing is small.