Okazaki Yusuke, Hoshi Shigeyuki, Kato Toshimasa, Fukui Takeo, Toda Kei, Ohira Shin-Ichi
Department of Chemistry, Kumamoto University, 2-39-1 Kurokami, Chuo-ku, Kumamoto 860-8555 Japan.
Kurita Water Industries Ltd., 1-1 Kawada Nogi-Machi, Shimotsugagun, Tochigi 329-0105, Japan.
ACS Omega. 2022 Apr 14;7(16):14082-14088. doi: 10.1021/acsomega.2c00648. eCollection 2022 Apr 26.
The presence of trace contaminants in ultra-pure water (UPW) used in fabrication process can greatly affect the yield and quality of industrial products. In the present study, the electrodialytic enrichment of metal cations as a means of continuously monitoring the UPW quality was studied. A newly designed electrodialytic enrichment device (EED) was used to quantitatively transfer metal ions from samples to dilute nitric acid, which was then directly introduced into an inductively coupled plasma-mass spectrometry (ICP-MS) instrument. This process could be performed without contamination of the sample, and the enrichment factor was solely dependent on the flow rate ratio of the sample and acceptor solutions. The transference of analytes into the acidic solution improved the responsivity of the ICP-MS analysis, especially at low concentrations of less than 1 μg/L. Blank solutions to support the analysis of UPW could be produced using the EED effluent, from which metal ions were quantitatively removed. In addition, calibration curves with concentration ranges of several nanograms per liter were obtained by preparing standards using a dynamic gravimetric method while employing a single bottle and continuous mass monitoring to avoid any contamination from the volumetric flasks. The sensitivities associated with the ICP-MS analysis of a number of trace metal ions were improved by one or two orders of magnitude. The data show that the present EED is able to continuously produce enriched analyte solutions to allow the ongoing monitoring of UPW quality.
制造过程中使用的超纯水（UPW）中痕量污染物的存在会极大地影响工业产品的产量和质量。在本研究中，研究了采用电渗析富集金属阳离子作为连续监测UPW质量的一种方法。使用新设计的电渗析富集装置（EED）将样品中的金属离子定量转移至稀硝酸中，然后将稀硝酸直接引入电感耦合等离子体质谱仪（ICP-MS）。此过程可在不污染样品的情况下进行，富集因子仅取决于样品和接受溶液的流速比。分析物转移到酸性溶液中提高了ICP-MS分析的响应度，尤其是在浓度低于1μg/L的低浓度情况下。使用EED流出物可制备用于支持UPW分析的空白溶液，其中的金属离子已被定量去除。此外，通过使用动态重量法制备标准品，同时采用单瓶和连续质量监测以避免容量瓶带来的任何污染，获得了浓度范围为每升几纳克的校准曲线。对多种痕量金属离子进行ICP-MS分析的灵敏度提高了一到两个数量级。数据表明，目前的EED能够连续生产富集的分析物溶液，以便持续监测UPW质量。
