亚甲蓝分光光度法测定水中阴离子表面活性剂的测量不确定度评定

Assessment Evaluation on Measurement Uncertainty of Detection Anionic Surfactants in Water Determined by Spectrophotometry Method with Methylene Blue

应用测量不确定度评定理论,结合亚甲蓝分光光度法对水中LAS测量不确定度进行全面分析,找出其影响不确定因素并对不确定度进行评估,实验分析表明亚甲蓝分光光度法测定水中LAS含量为20.3 mg/L的样品,其扩展不确定度为0.70 mg/L,影响不确定度最大的主要分量是样品重复性测量引入的不确定度,同时,提高量器精密度也是降低不确定度的有效方法。

Using the theory of measurement uncertainty evaluation and combining with the spectrophotometry method with methylene blue, the author made a comprehensive analysis of measurement uncertainty of LAS in water to find its influential factors of uncertainty and to evaluate the uncertainty, Experimental analysis shows that the content of LAS in water of the sample determined by spectrophotometry method with methylene blue is 203 mg/L, its expanded uncertainty is 0.70 mg/L, The main sources of uncertainty come from pre-processing step of samples, and one of effective ways to reduce the measurement uncertainty is promoting the accuracy of measuring vessel.