期刊
ANALYTICA CHIMICA ACTA
卷 1031, 期 -, 页码 67-74出版社
ELSEVIER SCIENCE BV
DOI: 10.1016/j.aca.2018.06.018
关键词
Chronopotentiometry; Ion-selective electrode; Calcium; Seawater; Current pulse
资金
- National Natural Science Foundation of China [21575158, 21677172]
- Chinese Academy of Sciences [Y728021021]
- National Key Research and Development Program of China [2016YFC1400700]
- CAS Youth Innovation Promotion Association [2014190]
- Taishan Scholar Program of Shandong Province [TS20081159]
Calcium is closely related to the oceanic biosphere and carbonate system. Potentiometry based on a calcium-selective electrode (Ca-ISE) represents a promising tool for detection of calcium ion activities in seawater. This technique, however, generally is limited by the low sensitivity for the inherent Nernstian response (i.e. ca 30 mV/dec). A current pulse based ion-selective electrode with enhanced sensitivity for chronopotentiometric measurements of calcium in seawater is proposed. The Ca2+-selective membrane containing lipophilic salt ETH 500 instead of traditional ion-exchanger is galvanostatically controlled. An applied constant cathodic current pulse can leads to the extraction of the calcium ions into the membrane to produce a chronopotential response, which shows a stable and reproducible super-Nernstian response in a narrow calcium activity range. The super-Nernstian region of the electrode depends on not only the the magnitude and duration of the applied current pulse but also the interfering ions. Under optimal conditions, the proposed Ca-ISE exhibits a super-Nernstian response between the calcium concentrations of 10(-)(2.5)-10(-)(1.5)M with a slope of ca 80 mV/dec. The current pulse based Ca-ISE has been applied to determination of calcium in seawater with satisfactory results. (C) 2018 Published by Elsevier B.V.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据