Sodium dithionite as a selective demasking agent for the complexometric determination of thallium

Sodium dithionite is proposed as a new demasking agent for the rapid and selective complexometric determination of thallium(III). In the presence of diverse metal ions, thallium (III) was first complexed with excess EDTA and the surplus EDTA was then titrated with a standard zinc sulphate solution at pH 5-6 (hexamine buffer) using Xylenol Orange as the indicator. The EDTA equivalent to thallium was then released selectively with sodium dithionite and back titrated with a standard zinc sulphate solution as before. Reproducible and accurate results were obtained in the range 4-100 mg of thallium with a relative error of +-27 % and a coefficient of variation (n = 6) of not more than 0.30 %. The effects of various diverse ions were studied. The method was applied to the determination of thallium in its complexes and in alloys.

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Indirect complexometric determination of mercury(II) in synthetic alloys and complexes using ethanethiol as a selective masking agent

Journal of the Serbian Chemical Society ◽

10.2298/jsc0603269k ◽

2006 ◽

Vol 71 (3) ◽

pp. 269-275

Author(s):

J. Karthikeyan ◽

P. Parameshwara ◽

Nityananda Shetty ◽

Prakash Shetty

Keyword(s):

Metal Ions ◽

Relative Error ◽

Coefficient Of Variation ◽

Zinc Sulphate ◽

Xylenol Orange ◽

Sulphate Solution ◽

Sample Solution ◽

Edta Complex ◽

Zinc Sulphate Solution

Acomplexometric method for the determination of mercury(II) in presence of other metal ions, based on the selective masking action of ethanethiol towards mercury( II) is described. Mercury(II) present in a given sample solution is first complexed with an excess of EDTAand the unreacted EDTAis titrated against zinc sulphate solution at pH 5-6 (hexamine buffer) using xylenol orange as the indicator. An excess of a 0.3 % solution of ethanethiol is then added to displace EDTA from the Hg(II)-EDTA complex. The released EDTAis titrated with a standard zinc sulphate solution. Reproducible and accurate results are obtained for 4-85 mg of mercury(II) with a relative error of less than +-0.46 % and coefficient of variation of not more than 0.47 %. The effects of the presence of various ions were studied. The method can be used for the analysis of mercury in its synthetic alloy mixtures and also in complexes.

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Determination of antimony in impure zinc sulphate solution by coprecipitation followed by differential pulse anodic stripping voltammetry

Talanta ◽

10.1016/0039-9140(96)01863-2 ◽

1996 ◽

Vol 43 (7) ◽

pp. 1069-1073 ◽

Cited By ~ 5

Author(s):

R DHANASEKHARAN ◽

R RAGHAVAN ◽

L AGARWAL

Keyword(s):

Zinc Sulphate ◽

Anodic Stripping Voltammetry ◽

Stripping Voltammetry ◽

Differential Pulse ◽

Sulphate Solution ◽

Anodic Stripping ◽

Zinc Sulphate Solution

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Homing behaviour of pigeons subjected to unilateral zinc sulphate treatment of their olfactory mucosa

Journal of Experimental Biology ◽

10.1242/jeb.199.11.2531 ◽

1996 ◽

Vol 199 (11) ◽

pp. 2531-2535 ◽

Cited By ~ 4

Author(s):

S Benvenuti ◽

A Gagliardo

Keyword(s):

Brain Damage ◽

Zinc Sulphate ◽

Experimental Treatment ◽

Olfactory Mucosa ◽

Initial Orientation ◽

Sulphate Solution ◽

Control Groups ◽

Homing Behaviour ◽

Homing Performance ◽

Zinc Sulphate Solution

Pigeons were made anosmic by unilateral treatment of their olfactory mucosa with a zinc sulphate solution and by plugging the contralateral nostril. In a series of releases at unfamiliar sites, 5579 km from the home loft, the experimental birds' homing behaviour was compared with that of two control groups: unmanipulated control birds, and birds subjected to unilateral zinc sulphate treatment and equipped with an ipsilateral nasal plug. The experimental pigeons exhibited homing behaviour  in terms of both homeward initial orientation and homing performance  significantly poorer than that of both unmanipulated and treated control pigeons. In addition, the homing behaviour of the treated controls turned out to be only slightly, and not significantly, poorer than that of the unmanipulated birds. The results show that the impaired homing capabilities of the zinc-sulphate-treated birds are due to the lack of navigational information and not to non-specific brain damage caused by the experimental treatment.

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