ICP-AES法测定保护渣中氧化钠的不确定度评定

UNCERTAINTY EVALUATION IN DETERMINATION OF SODIUM OXIDE IN MOLD FLUX BY ICP-AES

对电感耦合等离子体原子发射光谱法测定保护渣中氧化钠含量的不确定度来源进行了分析,依据国家计量技术规范JJF1059.1—2012《测量不确定度评定与表示》,建立了测量模型,量化了各不确定度分量,主要包括标准曲线配制、标准曲线拟合、测量重复性、样品称量以及样品定容,计算合成不确定度和扩展不确定度。当样品中氧化钠的含量为7.99%时,扩展不确定度为0.44%,氧化钠含量表示为7.99%±0.44%。该方法测定保护渣中氧化钠含量的不确定度较小,方法相对准确可靠。此次评定的不确定度主要来源为标准曲线拟合、测量重复性、标准曲线配制3个方面。

The sources of uncertainty are analyzed for the determination of sodium oxide in mold flux by inductively coupled plasma atomic emission spectrometry.According to the National Metrology Technical Specification JJF1059.1—2012“Evaluation and Representation of Measurement Uncertainty”,a measurement model is established to quantify the uncertainty components,including standard solution preparation,standard curve fitting,measurement repeatability,sample weighing and constant volume.The combined uncertainty and extended uncertainty are calculated.When the sodium oxide content in the sample is 7.99%,the expanded uncertainty is 0.44%,and the sodium oxide content is expressed as 7.99%±0.44%.The uncertainty of determination of sodium oxide in mold flux is relatively small,and the method is accurate and reliable.The main sources of uncertainty are from standard curve fitting,measurement repeatability and standard solution preparation.