• Analytical Science and Technology
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• v.14 no.2
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• pp.123-130
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• 2001

Determination of cadmium(II) ion with a perfluorinated sulfonated polymer-ethylenediamine(nafion-en) modified glassy carbon electrode was studied. It was based on the chemical reactivity of an immobilized layer(nafion-en) to yield complex $[Cd(en)_2]^{2+}$. The reduction peak potential by differential pulse voltammetry(DPV) was observed at $-0.780({\pm}0.005)V$ vs. As/AgCl. The linear calibration curve was obtained in cadmium(II) ion concentration range $5.0{\times}10^{-7}-2.0{\times}10^{-5}M$, and the detection limit(3s) was $2.20{\times}10^{-7}M$. The detection limit of nafion-en modified glassy carbon electrode has been shown about 14 higher sensitivity than a bare glassy carbon electrode.

• Journal of the Korean Chemical Society
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• v.19 no.6
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• pp.428-433
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• 1975

500 ml of a sample water was extracted with 10 ml of 0.01 % dithizone-$CHCl_3$three times. When $CHCl_3$ layer was back extracted with 10 ml of 0.1 N HCl containing mercuric ion, the free metal ions come into aqueous layer. The aqueous layer was added with 2 ml of 2 N KCl and was washed with 10 ㎖ of $CHCl_3$two times in order to remove the trace dithizone, and then was recorded square wave polarogram. The concentration of copper, lead and cadmium can be determined up to 3 ppb and that of zinc up to 14 ppb with an error of 10 %.

• Bulletin of the Korean Chemical Society
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• v.28 no.1
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• pp.68-72
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• 2007

A new PVC membrane potentiometric sensor that is highly selective to Hg2+ ions was prepared, using bis(2-hydroxybenzophenone) butane-2,3-dihydrazone (HBBD) as an excellent hexadendates neutral carrier. The sensor works satisfactorily in the concentration range of 1.0 × 10-6 to 1.0 × 10-1 mol L-1 (detection limit 4 × 10-7 mol L-1) with a Nernstian slope of 29.7 mV per decade. This electrode showed a fast response time (~8 s) and was used for at least 12 weeks without any divergence. The sensor exhibits good Hg2+ selectivity for a broad range of common alkali, alkaline earth, transition and heavy metal ions (lithium, sodium, potassium, magnesium, calcium, copper, nickel, cobalt, zinc, cadmium, lead and lanthanum). The electrode response is pH independent in the range of 1.5-4.0. Furthermore, the developed sensor was successfully used as an indicator electrode in the potentiometric titration of mercury ions with potassium iodide and the direct determination of mercury in some binary and ternary mixtures.