U. S. Environmental Protect Agency, Office of Research and Development, Center for Environmental Solutions & Emergency Response, Water Infrastructure Division, 26 W. Martin Luther King Dr., Cincinnati, OH 45268, United States of America.
Jacobs, 2 Crowne Point Court, Cincinnati, OH 45241, United States of America.
Sci Total Environ. 2023 Sep 15;891:163873. doi: 10.1016/j.scitotenv.2023.163873. Epub 2023 May 23.
Water lead measurements by two field analyzers, relying on anodic stripping voltammetry (ASV) and fluorescence spectroscopy, were compared to reference laboratory measurements by inductively coupled plasma mass spectrometry (ICP-MS) in progressively complex datasets (phases A, B, C), to assess field analyzer performance. Under controlled laboratory quantitative tests of dissolved lead within the field analysis range and optimal temperature range, lead recoveries by ASV ranged within 85-106 % of reference laboratory values (corresponding linear model: y = 0.96x, r = 0.99), compared to lower lead recoveries of 60-80 % by fluorescence (y = 0.69x, r = 0.99) in phase A. Field analyzer performance deteriorated in three opportunistic laboratory datasets compiled for phase B that contained dissolved lead (ASV: y = 0.80x, r = 0.98; no fluorescence data). Further lead underestimations were observed in five field datasets compiled for phase C, some of which contained known particulate lead (ASV: y = 0.54x, r = 0.76; fluorescence: y = 0.06x, r = 0.38). Deteriorating performance between phases was presumably due to the increasingly complex water matrices and lead particulates present in some phase C subsets (phase A < phase B < phase C). Phase C field samples had lead concentrations that were out-of-range, including a 5 % and 31 % false negative rate by ASV and by fluorescence, respectively. The range of results relevant to the diverse nature of compiled datasets, suggests that unless ideal conditions are known to be present (i.e., the lead content of water is dissolved within the field analysis range and optimal water temperature range), these field lead analyses might only be used as a water screening tool. Given the unknown conditions in many field settings, combined with the lead concentration underestimations including the false negative rates reported herein for field datasets, caution is encouraged when employing ASV and particularly fluorescence field analysis.
两种现场分析仪（基于阳极溶出伏安法（ASV）和荧光光谱法）的水铅测量值与电感耦合等离子体质谱法（ICP-MS）的参考实验室测量值进行了比较，这些数据来自逐步复杂化的数据集（A、B、C 阶段），以评估现场分析仪的性能。在现场分析范围内和最佳温度范围内对溶解铅进行的受控实验室定量测试下，ASV 的铅回收率在参考实验室值的 85-106%范围内（相应的线性模型：y=0.96x，r=0.99），而荧光法（y=0.69x，r=0.99）的回收率较低，为 60-80%，这是在 A 阶段。在为 B 阶段编制的三个包含溶解铅的机会性实验室数据集中，现场分析仪的性能恶化（ASV：y=0.80x，r=0.98；无荧光数据）。在为 C 阶段编制的五个现场数据集中，进一步观察到铅的低估，其中一些包含已知的颗粒状铅（ASV：y=0.54x，r=0.76；荧光：y=0.06x，r=0.38）。各阶段之间性能的恶化可能是由于水基质和某些 C 阶段子集（A 阶段< B 阶段< C 阶段）中存在的铅颗粒越来越复杂。C 阶段的现场样本的铅浓度超出了范围，ASV 和荧光的假阴性率分别为 5%和 31%。与编译数据集的多样性相关的结果范围表明，除非已知存在理想条件（即水中的铅含量溶解在现场分析范围内和最佳水温范围内），否则这些现场铅分析可能仅用作水筛选工具。考虑到许多现场环境的未知条件，再加上本文报告的现场数据集存在的铅浓度低估和假阴性率，在使用 ASV 和特别是荧光现场分析时，应谨慎行事。
