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  • Author or Editor: P. Reddy x
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Abstract  

A comparative study of the extractability of cadmium with potassium salts of ethyl, propyl, butyl, pentyl and benzyl xanthates into chloroform and a mixture of 14 pyridine and ethyl acetate from pH 1–7 buffers and sodium formate media, respectively, has been carried out employing an accurate and highly sensitive substoichiometric radiochemical method. The effect of foreign ions on the extractability was studied. The method developed was utilized for the determination of cadmium content in standard as well as in geological water samples.

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Abstract  

Radon and thoron have been identified as potential radiological health hazard and the dose estimation due to their exposure is an important task. Understanding their behavior in indoor environment helps in calculating the inhalation doses due to them. Present study aims at the distribution of radon and thoron concentrations in a typical Indian dwelling. Solid state nuclear track detectors are employed in the study. The concentration of radon is found to be invariant in indoor environment. The thoron concentration is found to decrease exponentially as a function of distance from the source (wall/floor). Solution of one dimensional diffusion equation is used for regression fittings for thoron variation, from which the diffusion constants and the exhalation rates were calculated. The diffusion constants varied from 0.00195 to 0.00540 m2 s−1.

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Abstract  

The relative extent of extraction of mercury with potassium salts of ethyl, propyl, butyl, pentyl and benzyl xanthates has been studied employing a sensitive and rapid substoichiometric radiochemical method. The effect of pH on the extractability of mercury xanthate complexes into chloroform was investigated. Buffer solutions of pH 12, 11, 10, 9 and 5.5 were found to be suitable media for the maximum extraction of mercury as ethyl, propyl, butyl, pentyl and benzyl xanthate complexes, respectively. The procedures developed were utilized for the determination of mercury content in standard solutions and geological water samples collected in eight parts of Chittoor district of Andhra Pradesh.

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Abstract  

A rapid and sensitive substoichiometric radiochemical method has been developed for the determination of microgram amounts of antimony employing potassium ethylxanthate as a reagent and chloroform as an extractant from sulfuric acid medium. The effect of associated ions on the extraction was studied. The method developed was successfully applied to determine the antimony content in standard solutions and synthetic mixture with an average error ±2.07%

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Abstract  

The comparative extractability of zinc with potassium salts of ethyl, propyl, butyl, pentyl, and benzyl xanthates from the pH range of 3.5–9.0 into chloroform has been studied, employing a sensitive and rapid substoichiometric radiochemical method. The extent of reproducibility was tested in each case. The effect of associated ions on the extraction was studied. The amount of zinc present in the standard solutions was determined employing each xanthate separately. The zinc content present in geological water samples in and around Tirupati was determined by the method developed and compared with the values obtained by Atomic Absorption Spectrophotometry.

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Abstract  

A sensitive and rapid radiochemical method has been developed for the determination of microgram amounts of indium(III) based on the substoichiometric extraction of its 13 complex with potassium ethyl xanthate from pH 7 ammonia buffer into chloroform. 5–50 g of indium was determined with an average error of 1.56%. The effect of associated species on the extraction was studied.

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A quantitative densitometric high-performance thin-layer chromatographic method for determination of nebivolol hydrochloride in pharmaceutical preparations has been established and validated. Nebivolol hydrochloride from the formulations was separated and identified on silica gel 60 F 254 HPTLC plates with toluene-ethyl acetate-methanol-formic acid, 8 + 6 + 4 + 1 ( v / v ), as mobile phase. The plates were developed to a distance of 8 cm. Densitometric quantification was performed at λ = 285 nm by reflectance scanning. Well resolved bands were obtained for nebivolol hydrochloride. The method was validated for precision, recovery, robustness, specificity, and ruggedness. The calibration plot for nebivolol hydrochloride standard was linear with r = 0.9991, slope = 3.291, and intercept = 864.50. The limits of detection and quantification were 18.65 and 62.18 ng per band, respectively. The method is selective and specific with potential application in pharmaceutical analysis.

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Abstract  

An accurate and rapid radiochemical method has been developed for the determination of silver based on the substoichiometric extraction of its complex with potassium 3-phenylmethyldithiocarbazate into chloroform from pH 5.5 acetate buffer. Microgram amounts of silver could be determined with an average error of ±1.1% and the effect of diverse metal ions was critically examined. The method developed was applied to evaluate the silver content of photofilm washings.

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