连续流动法测定纸张中六价铬的测量不确定度评定

[目的]评定连续流动法测定烤烟型卷烟纸张中六价铬的测量不确定度。[方法]分析了测量过程,修订了连续流动法测定纸张中六价铬的测定因果关系图,建立了测量不确定度评定的数学模型。分析样品前处理、标准溶液配制、校准曲线拟合、测量重复性等因素引入的不确定度,确定其测量不确定度的主要来源。[结果]连续流动法测定纸张中六价铬的不确定度的主要来源为样品的浓度和测量重复性。通过对不确定度进行评定,得出连续流动法测定纸张中六价铬测量结果的标准不确定度为0.003 5 mg/kg,在95%的置信度下,取包含因子为k=2,其扩展不确定度为0.007 0 mg/kg。[结论]研究可为充分把握六价铬含量测定的关键影响因素,提高测定结果的准确性提供科学依据。

Uncertainty in Determination of Hexavalent Chromium in Tipping Paper by Continuous Flow Method

[Objective] In order to evaluate measurement uncertainty for hexavalent chromium in paper of flue-cured type cigarette with continuous flow method.[Method] The process of measurement was analyzed,paper continuous flow method on the determination of hexavalent chromium in causality diagram was revised,the mathematics model was established.The sample preparation,the standard solution preparation,calibration curve fitting,measurement repeatability were analyzed to determine the main sources of the uncertainty of measurement.[Result] The main sources of the uncertainty were the concentration of sample and measurement repeatability.The standardized uncertainty of the measurement result was 0.003 5 mg/kg.Under the confidence level of 95%,when the comprising factor k was equal to 2,the expanded uncertainty was 0.007 0 mg/kg.[Conclusion] The study can provide scientific basis for fully grasping the key factors for the determination of hexavalent chromium content,improving accuracy of determination results.