食用槟榔中二氧化硫含量检测的不确定度评定

Evaluation of Uncertainty in the Determination of Sulfur Dioxide in Areca Catechu

针对食用槟榔中二氧化硫含量检测过程引入的不确定度进行评定。通过建立数学模型分析检测过程中不确定度的来源,可知其不确定度来源主要来自测量重复性、样品的称量、标准溶液标定与稀释过程、样品滴定过程等。结果表明,在95%置信概率下,食用槟榔中二氧化硫的含量为0.0206±0.000991 g/kg,k=2。食用槟榔中二氧化硫含量未超过国标规定的限量标准0.35 g/kg,并且得出标准溶液滴定过程和测量重复性引入的不确定度较大,样品称量、标准溶液标定与稀释过程次之。

In this paper,the uncertainty introduced in the detection process of sulfur dioxide content in areca catechu was evaluated.Through the establishment of mathematical model to analyze the sources of uncertainty in the detection process,it could be seen that the sources of uncertainty mainly come from measurement repeatability,sample weighing,standard solution calibration and dilution process,sample titration process,etc.The experimental results showed that under 95%confidence probability,the content of sulfur dioxide in edible areca nut was 0.0206±0.000991 g/kg,k=2.The content of sulfur dioxide in edible areca nut does not exceed 0.35 g/kg of the national standard,and the uncertainty of titration process and measurement repeatability was large,followed by sample weighing,standard solution calibration and dilution process.