Department of Chemistry, Renewable Natural Resources and Chemistry of Living Environment, University of Jyväskylä, P.O. Box 35, FI-40014, Jyväskylä, Finland.
Department of Chemistry, Renewable Natural Resources and Chemistry of Living Environment, University of Jyväskylä, P.O. Box 35, FI-40014, Jyväskylä, Finland.
Talanta. 2020 Oct 1;218:121125. doi: 10.1016/j.talanta.2020.121125. Epub 2020 May 8.
An analytical method was developed for the direct determination of total mercury in natural waters at low ng L level by inductively coupled plasma mass spectrometry (ICP-MS). The presented method overcomes previously observed problems relating to poor spike recoveries by adding 0.12% thiourea in addition to 3% HCl to all samples and standards. The sample preparation is fast and easy to perform by the developed method since it requires only the addition of HCl and thiourea to the water samples. A very low instrument detection limit (0.4 ng L) was obtained without time-consuming preconcentration procedures. The accuracy and precision of the developed method were found excellent by the analysis of a certified groundwater reference material (ERM-CA615). The determined Hg concentration of 38.6 ± 0.5 ng L was within the 95% confidence interval of the certified concentration of 37 ± 4 ng L. The analysis of natural water samples showed that total mercury levels ranged from concentrations lower than the method detection limit (2.0 ng L) to 10.9 ng L. Excellent recoveries of 96-108% for inorganic mercury (iHg) and 102-110% for methylmercury (MeHg) were obtained for spiked humic-rich natural water samples. To our knowledge, the developed method is the first ICP-MS method for the analysis of humic-rich natural water samples at ng L concentrations without the need for hyphenated techniques or preconcentration procedures.
建立了一种采用电感耦合等离子体质谱（ICP-MS）直接测定天然水中痕量总汞的分析方法。该方法通过在所有样品和标准品中添加 0.12%硫脲和 3%盐酸，克服了先前观察到的由于刺回收率差而导致的问题。该方法的样品制备快速且易于操作，因为仅需在水样中添加盐酸和硫脲。通过分析一种认证的地下水标准物质（ERM-CA615），获得了非常低的仪器检测限（0.4ng L），而无需进行耗时的预浓缩程序。通过对认证浓度为 37±4ng L 的地下水标准物质的分析，发现该方法的准确性和精密度非常好。所测定的 Hg 浓度为 38.6±0.5ng L，在认证浓度 37±4ng L 的 95%置信区间内。对天然水样的分析表明，总汞浓度范围从低于方法检测限（2.0ng L）到 10.9ng L。对富腐殖质天然水样进行加标实验，得到无机汞（iHg）的回收率为 96-108%，甲基汞（MeHg）的回收率为 102-110%。据我们所知，该方法是首个无需联用技术或预浓缩程序即可分析 ng L 浓度富腐殖质天然水样的 ICP-MS 方法。
