Khani H, Rofouei MK, Arab P, Gupta VK, Vafaei Z. Multi-walled carbon nanotubes-ionic liquid-carbon paste electrode as a super selectivity sensor: application to potentiometric monitoring of mercury ion(II).
JOURNAL OF HAZARDOUS MATERIALS 2010;
183:402-9. [PMID:
20692088 DOI:
10.1016/j.jhazmat.2010.07.039]
[Citation(s) in RCA: 416] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Revised: 06/28/2010] [Accepted: 07/09/2010] [Indexed: 05/10/2023]
Abstract
In this article a super selectivity potentiometric methodology, using an ion-selective electrode, for determination of mercury ion(II) in aqueous solution was investigated. For modification of the electrode a room temperature ionic liquid, 1-n-butyl-3-methylimidazolium tetrafluoroborate (BMIM·BF(4)), was applied as a super conductive binder, and Multi-walled carbon nanotubes (MWCNTs) was used in the composition of the carbon paste to improve conductivity and transduction of chemical signal to electrical signal. Moreover, incorporation of 1-(2-ethoxyphenyl)-3-(3-nitrophenyl)triazene (ENTZ) as an ionophore to this composition caused to significantly enhanced selectivity toward Hg(II) ions over a wide concentration range of 1.0×10(-4) to 5.0×10(-9) M with a lower detection limit of 2.5×10(-9) M (0.5 ppb) and a Nernstian slope of 29.3±(0.2) mV decade(-1) of Hg(II) activity. The electrode has a short response time (∼5s) and can be used for at least 55 days without any considerable divergence in potentials, and the working pH range was 2.0-4.3. Finally, the proposed electrode was successfully used as an indicator for potentiometric determination of Hg(II) in dental amalgam and water samples.
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