石墨炉原子吸收光谱法测螺旋藻中镉含量的不确定度分析

The uncertainty assessment for testing the concentration of cadmium in Spirulina by graphite furnace atomic absorption spectrometry

目的分析石墨炉原子吸收光谱法测定螺旋藻中镉含量不确定的影响水平,找出关键影响因素。方法用数学模型对各影响分量进行不确定度分析,最后得到合成不确定度以及扩展不确定度。结果螺旋藻中镉含量为样品镉含量为(0.111±0.011)μg/g,k=2。结论影响石墨炉原子吸收光谱法测定螺旋藻中镉含量结果不确定度的主要因素是校准曲线拟合计算样品浓度、标准溶液本身及其配制标准系列过程、样品测量重复性。而样品定容体积、样品称重、温度变动等影响相对较小。

Objective To analysis influence the level of uncertainty of cadmium content in Spirulina by graphite furnace atomic absorption spectrometry, find out the key influencing factors.Methods Using the mathematical model for uncertainty analysis of the effect of each component, the combined uncertainty and expanded uncertainty. Results The cadmium content in cadmium content of Spirulina samples（0.111 ± 0.011）μg/g, k=2. Conclusions Determination of cadmium content of Spirulina in the uncertainty of calibration curve fitting to calculate the sample concentration, standard solution and its preparation of standard series of sample measurement process, repeated effect of graphite furnace atomic absorption spectrometry. The effects of sample volume, sample weight, temperature change is relatively small.