Determination of cadmium in water samples by substoichiometric radiochemical method employing potassium ethyl xanthate

A radiochemical method has been developed for the determination of microgram amounts of cadmium based on the substoichiometric extraction of its 1:2 complex with potassium ethyl xanthate into 1:4 v/v mixture of pyridine and ethyl acetate from 2.5 M sodium formate. 10-90 micrograms of cadmium was determined with an average error of +/- 1.96%. The method developed was successfully applied to the determination of Cd contents in water samples.     

Comparative substoichiometric extraction and quantification of mercury in geological water samples with potassium salts of ethyl,propyl, butyl,pentyl and benzyl xanthates

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.     

Substoichiometric determination of zinc with potassium ethyl xanthate

A rapid radiochemical method has been designed for the determination of microgram quantities of zinc, based on the substoichiometric isotope dilution, using potassium ethyl xanthate as the extraction reagent. pH 5.5 in acetate buffers and chloroform as the extractant were found to be suitable for quantitative substoichiometric extraction. The influence of the diverse ions on the extraction was studied. The zinc contents of a medicinal preparation and biological samples were determined by the present method.     

Substoichiometric determination of selenium with potassium ethyl xanthate

A substoichiometric radiochemical method has been developed for the determination of selenium with potassium ethyl xanthate. The selenium ethyl xanthate complex formed was extracted into chloroform from borate buffer at pH 5. The effect of foreign ions on the extraction was studied. Microgram quantities of selenium could be conveniently determined with a fair degree of accuracy. The method has been successfully applied for the determination of selenium content in food stuffs such as Jaggery and Wheat powder.     

Determination of trace amounts of the flotation collectors ethyl xanthate and diethyl dithiophosphate in aqueous solutions by cathodic stripping voltammetry

A cathodic stripping method has been devised for determination of low concentrations of the flotation collectors ethyl xanthate, diethyl dixanthogen and diethyl dithiophosphate. The limit of detection for ethyl xanthate was 1 x 10(-8)M by the differential pulse technique and with deposition for 2 min at -0.1 V. Three peaks were observed, each increasing in different concentration ranges of ethyl xanthate. A reaction mechanism is proposed. The detection limit for diethyl dithiophosphate was 1 x 10(-7)M by the differential pulse technique and with deposition for 3 min at -0.1 V. The analytical method was applied to determine ethyl xanthate in a sulphide mineral flotation plant and the amount of adsorbed ethyl xanthate and diethyl dithiophosphate on Cu(2)S. It was found that the adsorbed ethyl xanthate forms nearly a monolayer on Cu(2)S and that the amount of adsorbed diethyl dithiophosphate corresponds approximately to 0.4 monolayer.     

Comparative substoichiometric extraction of silver with potassium salts of ethyl,propyl, butyl,pentyl and benzyl xanthates

A rapid and sensitive substoichiometric radiochemical method has been developed for the comparative extraction and quantification of silver with potassium salts of ethyl, propyl, butyl, pentyl and benzyl xanthates from hydrochloric, nitric and sulfuric acid media into chloroform. The effect of 0.1–4M H⁺ ion concentration of the respective acid on the substoichiometric extraction of silver was critically studied. The efficiency of the method developed was tested by the determination of 10–100 μg silver in standard solutions with an average percentage of error better than 2. The methods developed have been utilized to determine silver content in photofilm washing collected from various photostudios in Tirupati, India.     

Utilization of potassium ethyl xanthate as a substoichiometric reagent for the determination of indium

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.     

Adsorption of ethyl xanthate anions on a silver electrode. An in-situ FTIR study

The adsorption of ethyl xanthatc ion (EX⁻) on a silver electrode in sodium sulphate, phosphate buffer (pH 6.8) and borate buffer (pH 9.2) solutions was studied in situ using Fourier transform IR reflection spectroscopy. The measurements were carried out using a thin-layer flow cell, which allows a continuous supply of the electroactive species into the thin layer. The voltammetric behaviour of the silver electrode in EX⁻-containing solution is characterized by the formation of silver ethyl xanthate (AgEX), which is preceded by a prewave due to chemisorption of ethyl xanthate. An IR band at 1220 cm ⁻¹, assigned to chemisorbed ethyl xanthate, was observed in spectra obtained in the chemisorption region. All IR bands characteristic of AgEX were observed in spectra of a silver electrode surface covered by a few monolayers of AgEX. The in-situ IR measurements also showed that the adsorption of EX⁻ starts directly on the positive side of the potential of zero charge of silver (−0.7 V/SHE).     

Comparative substoichiometric extraction of silver with potassium salts of ethyl, propyl, butyl, pentyl and benzyl xanthates

A rapid and sensitive substoichiometric radiochemical method has been developed for the comparative extraction and quantification of silver with potassium salts of ethyl, propyl, butyl, pentyl and benzyl xanthates from hydrochloric, nitric and sulfuric acid media into chloroform. The effect of 0.1–4M H⁺ ion concentration of the respective acid on the substoichiometric extraction of silver was critically studied. The efficiency of the method developed was tested by the determination of 10–100 g silver in standard solutions with an average percentage of error better than 2. The methods developed have been utilized to determine silver content in photofilm washing collected from various photostudios in Tirupati, India.     

Comparative substoichiometric extraction of zinc with potassium salts of ethyl,propyl, butyl,pentyl and benzyl xanthates

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.     

A potentiometric determination of potassium ethyl xanthate

A potentiometric determination of potassium ethyl xantbate with Cu(II)-acetate is described From the results it follows that CS₂ reacts quantitatively with etimnolic KOH to give potassium ethyl xanthate The method may therefore be used for the determination of CS₂.     

Determination of xanthates as Cu(II) complexes by high-performance liquid chromatography – Inductively coupled plasma tandem mass spectrometry

The present study provides a novel, selective analysis method for the determination of low xanthate concentrations. The rising concern over the environmental effects of xanthates demands the development of analysis methods which this study answers. Complex formation in aqueous solution between xanthates and an excess of Co(II), Ni(II), Pb(II), Cd(II), Cu(II), and Zn(II) ions was utilized to selectively determine xanthates by high-performance liquid chromatography–inductively coupled plasma tandem mass spectrometry for the first time. The complexes that were formed were extracted to ethyl acetate using liquid–liquid extraction and separated by high-performance liquid chromatography technique before the quantitative determination of metal ions and sulfur in the xanthate complexes. Good separation and high measurement sensitivity were achieved using Cu(II) as the complex metal ion. The analysis method was optimized for the determination of sodium isopropyl xanthate and sodium isobutyl xanthate with detection limits of 24.7 and 13.3 μg/L, respectively. With a linear calibration range of 0.1–15 mg/L and a total analysis time of 4–5 min, the present method is a fast and sensitive option for selective xanthate determination.     

Capillary electrophoretic determination of dithiocarbamates and ethyl xanthate

A simple and sensitive capillary electrophoretic method was developed for the separation and determination of sodium methyldithiocarbamate (metham), manganese ethylenebisdithiocarbamate (maneb) and ethyl xanthate in boric acid buffer by direct UV absorbance detection at lambda = 254 nm. The separation is dependent on pH and nature of the buffer. The detection limits (S/N = 3) are 1.7 x 10(-6) mol/L for ethyl xanthate, 1.3 x 10(-6) mol/L for metham and 2.1 x 10(-6) mol/L for maneb. The method has been successfully applied to the analysis of wheat samples spiked with maneb and in a commercial sample.     

Flow injection analysis of ethyl xanthate by in-line dialysis and UV spectrophotometric detection

A simple and sensitive spectrophotometric flow method for determination of low concentrations of the flotation collector O-ethyldithiocarbonate (ethyl xanthate, CH₃CH₂-O-CS₂⁻) in solutions is described. The method is based on ethyl xanthate detection at 301 nm in medium of NaOH 50 mmol L⁻¹. By injection of 200 μL of sample, the analytical method shows linear response for the ethyl xanthate concentration from 0.5 up to 500 μmol L⁻¹. Successive injections of 4 μmol L⁻¹ ethyl xanthate (n = 23) show a coefficient of variation lower than 0.6%, denoting high repeatability. The detection limit is 0.3 μmol L⁻¹. At a flow rate of 2.0 mL min⁻¹, a frequency of 120 injections/h of ethyl xanthate can be attained. By introduction of a tangential dialysis cell in the FIA system, the manual sample filtration step with 0.22 μm filter was eliminated and the residual interference of suspended material, was completely overcome even for unfiltered sludge suspension samples, an important advantage that compensates for the frequency reduction to 25 injections/h elevation and detection limit elevation to 2 μmol L⁻¹, still outreaching for many applications. Potential applications of the method embrace the at line determination of ethyl xanthate in the ore processing industry, control of the concentration at its optimal level during the flotation process, as well as monitoring of residues in the effluents.     

Potassium 3-phenylmethyldithiocarbazate as substoichiometric reagent: Determination of silver

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.     

Capillary electrophoretic determination of dithiocarbamates and ethyl xanthate

A simple and sensitive capillary electrophoretic method was developed for the separation and determination of sodium methyldithiocarbamate (metham), manganese ethylenebisdithiocarbamate (maneb) and ethyl xanthate in boric acid buffer by direct UV absorbance detection at λ = 254 nm. The separation is dependent on pH and nature of the buffer. The detection limits (S/N = 3) are 1.7 × 10^–6 mol/L for ethyl xanthate, 1.3 × 10^–6 mol/L for metham and 2.1 × 10^–6 mol/L for maneb. The method has been successfully applied to the analysis of wheat samples spiked with maneb and in a commercial sample.     

Reduction and determination of dixanthogens

A convenient method for the reduction and determination of dixaathogen has been developed. It is based on the quantitative reaction of dixanthogen with zinc amalgam to form xanthate; the latter can be determined by iodine titration, potentiometric titration with silver nitrate or by spectrophotometry at 310 mmu. Dixanthogen can be determined in mixtures containing xanthate, by titration of aliquots with and without reduction. Higher dixanthogens can also be determined, and flotation liquors analysed.     

Rapid radiochemical separations in neutron activation analysis using ion retention media

A rapid radiochemical procedure based on the removal of mercury, selenium, arsenic and antimony by columns of C₁₈-bonded silica gel or activated carbon after their selective complexation in sulphate/nitrate media by ammonium pyrrolidine-dithiocarbamate, diethylammonium diethyldithiocarbamate, potassium ethyl xanthate, bismuthiol II or 8-hydroxyquinoline, was examined. Comparisons were made of the ability of the two ion retention media to remove these metal ions and to allow their regeneration and recycling. The effectiveness of this technique was demonstrated by analysis of horse kidney and human diet, International Atomic Energy Agency biological reference materials, for mercury and selenium.     

Microdetermination of Xanthates

Summary A rapid, convenient and accurate method for the determination of xanthates has been developed. N-bromosuccinimide has been used to displace iodine from potassium iodide which in turn oxidizes xanthate to dixanthogen. The p_H 4 is optimum for the determination. The maximum relative standard deviation is 6% in the case of ethyl potassium xanthate when a 0.5 mg sample was taken.

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Zusammenfassung Ein genaues Verfahren zur raschen Bestimmung von Xanthat wurde entwickelt. N-Bromsuccinimid dient zur Freisetzung von Jod aus KJ; Jod oxydiert Xanthat zu Dixanthogen. Das optimale p_H für die Bestimmung ist 4. Die größte relative Standardabweichung ist 6% bei einer Einwaage von 0,5 mg Kaliumäthylxanthat.

     

Substoichiometric radiochemical determination of thallium with sodium isopropyl xanthate

A rapid radiochemical method for the determination of thallium(III) has been developed based on the substoichiometric extraction of its 13 complex with sodium isopropyl xanthate into chloroform from pH 9 ammonia buffer. The effect of foreign ions on the extraction was also studied. 10 g amounts of thallium were determined with an average error of 1.9%. The method has been successfully applied for the determination of thallium content present in sphalarite ores collected from Jawar Mines, Rajasthan (India).