Cathodic Stripping Voltammetric Determination of Tellurium(IV) in Chloride Media Using a Tosflex/8-Quinolinol Mercury Film Electrode

Abstract

A Tos¯exa8-quinolinol (oxine) coated mercury ®lm electrode (TOMFE) was developed for the determination of tellurium(IV) by squarewave cathodic voltammetry. The electrode is prepared by spin-coating a Tos¯exaoxine solution onto the glassy carbon electrode surface. Subsequently, mercury is plated onto the electrode surface. Tellurium(IV) is preconcentrated, as TeCl 2À 6 in the chloride medium, onto the modi®ed electrode by the ion-exchange effect of the Tos¯ex and the chelating effect of oxine. Good sensitivity was achieved through the catalytic process between oxine and tellurium. In comparison with the conventional mercury electrode, the TOMFE showed improved resistance to interferences from surface-active compounds on the determination of tellurium(IV). The interferences from metal ions, such as cadmium(II) and molybdenum(VI), which are capable of forming complexes with oxine were effectively eliminated by the addition of ethylenediaminetetraacetate (EDTA) in the sample solution. The TOMFE is easy to prepare and chemically more stable than other anionexchange polymer modi®ed electrodes such as polyvinylpyridine modi®ed mercury ®lm electrode.

Cathodic Stripping Voltammetry of Tellurium(IV) at a Bismuth Film Electrode

“…A Tosflex/8-quinolinol coated HgFE has been reported for Te determination. 21 Our laboratories developed a stripping voltammetric technique for compositional analysis of electrodeposited CdSe thin films using HgFEs. 22 However, there are no reports on the observation of compound formation during stripping analysis of Te(IV) or Se(IV).…”

Voltammetric Ultra Trace Determination of Tellurium

“…Several methods such as flameless atomic absorption (Liu et al 2003;Nakamoto et al 2004), X-ray fluorimetry (Cava Montesions et al 2003), ion-exchange chromatography (Lee et al 2003), and HPLC-ICMS (Xang and Wen Sun 1999) are reported in determination of microgram level tellurium. The procedures require preliminary treatment of the sample (in addition to any concentration step) to bring the Te to the proper state for measurement by preoxidation or reduction.…”