流动注射法与传统分光法检测饮用水中挥发酚的比较及其不确定度评定

Comparison of FIA and Traditional Spectrophotometry for Assaying Volatile Phenols in Water and its Uncertainty Evaluation

本研究分别采用FIA法和传统分光光度法测定水中不同浓度含量挥发酚并进行了多组基体加标实验,结果表明对于不同浓度水平及不同基体加标样品的测定,2种方法的精密度和准确度均符合标准相关要求,对检测结果进行配对t检验,两种方法测定结果无显著差异,但流动注射法相比传统分光光度法有更高的精密度和更宽的线性范围,且检测方法更简便、快捷,安全性和自动化程度更高,更利于第三方检测机构大批量高效测定样品。为更科学、合理的表示FIA法检测水中挥发酚含量的测定结果,对FIA法检测挥发酚过程中的不确定度来源进行了分析,得出测量结果的扩展不确定度,结果表明除去标准溶液,样品重复性测定引入的不确定度最大;当水中挥发酚含量为9.1 ug/L时,其扩展不确定度为0.3 ug/L(k=2)。

In this study,FIA and traditional spectrophotometry were used to determine volatile phenols in water at different concentrations,and multiple groups of matrix spike experiments were performed.The results showed that for the determination of spiked samples with different concentration levels and different matrices,the precision and accuracy of the two methods were in accordance with the analysis criteria,the t-test showed that the content data acquired from these two methods had no significant difference.However,the FIA has higher precision and wider linear range,it is simpler,faster and has a higher degree of safety and automation,which is more in line with the requirements of third-party testing organizations for large-scale and efficient determination of samples.For a more scientific and reasonable representation of the measurement results of volatile phenol content in water by FIA method,the sources of uncertainty in FIA for volatile phenols were analyzed,the results showed that removing the standard solution,the main source of uncertainty introduced by the sample repeatability measurement;When the volatile phenol content in the water is 9.1 ug/L,the extended uncertainty is 0.3 ug/L(k=2).