目的建立测定明胶中铬含量不确定度的分析方法。方法根据《测量不确定度评定与表示》的有关规定,参考《化学分析测量不确定度评定》,对石墨炉原子吸收光谱法测定明胶中铬含量不确定各分量进行分析,进而求得合成标准不确定度及扩展不确定度。结果该次检测明胶铬结果 0.117 mg/kg,相对合成不确定度为0.062 6,扩展不确定度为0.015 mg/kg(k=2),最后结果表示(0.117±0.015)mg/kg(k=2,95%置信水平)。结论运用此不确定度分析方法控制测量过程中的关键步骤,严格操作规范,可有效地降低引入的不确定度,使测定结果更可靠,同时结果表述时采用不确定度更能体现结果的准确程度。
Objective To build the analysis method of measuring the uncertainty of chromium in gelatin content. Methods The components of graphite furnace atomic absorption spectrometry in measuring the chromium in gelatin content were analyzed according to the relevant regulations of evaluation and expression of uncertainty in measurement and chemical analysis evaluation of uncertainty in measurement, and then the synthetic standard uncertainty and expansion uncertainty were concluded. Results The detection showed gelatin chromium result was 0.117mg/kg, relatively composite uncertainty was0.0626, expansion uncertainty was 0.015mg/kg(k=2), and the final result was(0.117±0.015) mg/kg(k=2, 95% confidence level). Conclusion Controlling the critical steps in the measurement process by applying the uncertainty analysis method and strict operation specifications can effectively reduce the introduction uncertainty and make the measurement results more reliable, at the same time, adopting uncertainty at the time of result presentation can more reflect the accurate degree of results.