State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China.
Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China.
Anal Chem. 2022 Mar 15;94(10):4455-4462. doi: 10.1021/acs.analchem.1c05524. Epub 2022 Mar 1.
A novel simple electrothermal desolvation-enhanced dielectric barrier discharge plasma-induced vapor generation (ETD-DBD-PIVG) method has been developed for sensitive Sb determination by atomic fluorescence spectrometry (AFS). In our proposed ETD-DBD-PIVG, 20 μL sample solution was dried first; then, the resulting solution residue was directly converted into molecular volatile species efficiently through the interactions with hydrogen-doped DBD plasma; and finally, it was transported to AFS for detection. It was found that the desolvation process could greatly enhance Sb vapor generation, and the Sb fluorescence signal intensity is almost independent of its speciation, where comparable sensitivity is achieved for Sb(III) and Sb(V), enabling efficient total Sb detection without pre-reduction. Influencing parameters were evaluated in detail, including heating time, discharge gap, solution pH, and flow rates of argon and hydrogen, as well as coexisting ion interference. Under optimized conditions, the limit of detection was calculated as 0.86 μg L (17.2 pg) for Sb. The accuracy of the proposed method was validated by the analysis of certified reference materials of simulated natural water samples and several river water samples. Compared with conventional hydride generation, the new ETD-DBD-PIVG offers an alternative green vapor generation technique with several advantages: (1) it eliminates the use of a sample flow system (e.g., no use of any syringe or peristaltic pump); instead, 20 μL of a sample is directly pipetted onto the glass plate for analysis; (2) it greatly simplifies the sample pretreatment steps as no pre-reduction process is needed; (3) it is sensitive and suitable for volume-limited sample analysis: efficient Sb vapor generation without chemical reducing reagents in ETD-DBD-PIVG enables Sb detection with an absolute limit at the picogram level. All the results demonstrate that the proposed method provides a simple, green, and sensitive method for Sb determination and it can also be extended to other elements such as Cd and As.
一种新颖的简单电热解吸增强介电阻挡放电等离子体诱导蒸汽发生（ETD-DBD-PIVG）方法已被开发出来，用于通过原子荧光光谱法（AFS）对 Sb 进行灵敏测定。在我们提出的 ETD-DBD-PIVG 中，首先将 20 μL 样品溶液干燥；然后，通过与掺氢 DBD 等离子体的相互作用，将所得溶液残渣有效地转化为分子挥发性物质；最后，将其输送到 AFS 进行检测。研究发现，解吸过程可以大大增强 Sb 蒸汽发生，并且 Sb 荧光信号强度几乎与其形态无关，从而可以实现 Sb(III)和 Sb(V)的等效灵敏度，无需预还原即可进行有效的总 Sb 检测。详细评估了影响参数，包括加热时间、放电间隙、溶液 pH 值以及氩气和氢气的流速，以及共存离子的干扰。在优化条件下，Sb 的检出限计算为 0.86 μg L（17.2 pg）。通过对模拟天然水样和几种河水样品的标准参考物质的分析验证了该方法的准确性。与传统的氢化物发生法相比，新的 ETD-DBD-PIVG 提供了一种替代的绿色蒸汽发生技术，具有以下优点：（1）它消除了对样品流动系统的使用（例如，无需使用注射器或蠕动泵）；相反，20 μL 样品直接用移液管滴在玻璃板上进行分析；（2）它大大简化了样品预处理步骤，因为不需要预还原过程；（3）它具有灵敏性，适用于有限体积的样品分析：在 ETD-DBD-PIVG 中，无需化学还原剂即可实现高效的 Sb 蒸汽发生，使 Sb 检测能够达到皮克级别的绝对极限。所有结果表明，该方法为 Sb 的测定提供了一种简单、绿色、灵敏的方法，并且还可以扩展到其他元素如 Cd 和 As。
