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 (∼5
s) 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.