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 cadmium with potassium salts of ethyl,propyl, butyl,pentyl and benzyl xanthates

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.     

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.     

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.     

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 radiochemical determination of mercury with potassium benzyl xanthate

A sensitive and rapid radiochemical method has been developed for the determination of microgram amounts of mercury by substoichiometric extraction of its 12 complex with potassium benzyl xanthate into chloroform from pH 5.5 acetate buffer. The influence of various foreign ions on the extraction was studied. 2–20 g of mercury was determined with an average error of 1.78%. The method developed was utilized to determine the mercury content of water samples.     

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.     

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 radiochemical determination of antimony with potassium ethyl xanthate

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%     

Substoichiometric radiochemical determination of silver with potassium ethyl xanthate in photofilm washings

An accurate and rapid radiochemical method has been developed for the determination of microgram amount of silver employing potassium ethyl xanthate as a substoichiometric radiochemical reagent. The light yellow coloured silver ethyl xanthate formed was extracted into nitrobenzene from sulphuric acid media. The effect of foreign ions on the extraction was studied. The method was applied to the determination of silver content in photofilm washings.     

Spectrophotometric determination of bismuth,cobalt, and nickel after extraction of their xanthates with molten naphthalene

Summary A new method for the spectrophotometric determination of bismuth, cobalt and nickel after extraction of their xanthates into molten naphthalene is described. The optimum pH values are 2.4–4.5 for Bi, 7.5–9.0 for Co, 5.5–7.5 for Ni. The naphthalene containing the metal chelates is dissolved in chloroform, and the absorbance is measured against a reagent blank at 362, 350 and 420 nm for Bi, Co and Ni and respectively. Few ions interfere and the method has been applied successfully for the determination of these metal ions in various complex materials.

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Zusammenfassung Eine neue Methode für die spektrophotometrische Bestimmung von Wismuth, Kobalt und Nickel nach Extraktion ihrer Xanthate mit geschmolzenem Naphthalin wurde beschrieben. Das optimale pH für Wismut beträgt 2,4–4,5, für Kobalt 7,5–9,0 und für Nickel 5,5–7,5. Das die Metallchelate enthaltende Naphthalin wird in Chloroform gelöst und die Extinktion gegen eine Reagens-Leerlösung bei 362, 350 bzw. 420 nm für Bi, Co bzw. Ni gemessen. Nur wenige Ionen stören. Das Verfahren wurde mit Erfolg zur Bestimmung der genannten Ionen in verschiedenen komplexen Gemischen angewandt.

     

Substoichiometric masking-II Determination of traces of cobalt in nickel salts and metallic nickel

Cobalt is determined in the presence of large amounts of nickel by masking the latter substoichiometrically by addition of xxx 98% of the theoretically required amount of EDTA. The "free nickel" :cobalt ratio is thereby decreased below the critical value and the cobalt is extracted as the green cobalt(III)-PAN complex into chloroform. Small amounts of nickel-PAN formed are destroyed by a subsequent EDTA-hydrochloric acid treatment. The absorbance of the treated extract is measured at 635 mmu. Copper, zinc, cadmium and iron do not interfere in ratios (to cobalt) of 500:1, 100:1, 100:1 and 10:1, respectively.     

Chloroform extraction of metal ethyl xanthates from hydrochloric acid media

The chloroform extraction of 32 elements (Fe, Co, Ni, Zn, Cd, Ge, Sn, Pb, V, As, Sb, Bi, Cu, Ag, Au, Mn, Re, Ga, In, Tl, Ce, Se, Te, Cr, Mo, U, Pt, Pd, Rh, Ir, Ru and Os) from O.1-10M hydrochloric acid media in the presence of potassium ethyl xanthate has been studied. The oxidation states in which some elements react, and potential analytical separations, are discussed. Pd(II), As(III) and Se(IV) are completely extracted as ethyl xanthate complexes, Te(IV) is almost completely extracted, and Au(III) is largely extracted over the range of acid concentration investigated. Mn(II), Zn, Rh(III), Ir(IV), Ru(III), Os(IV), Cr(III), Cr(VI), Ce(III) and Ce(IV) are not extracted. Ge is partly extracted from 6-10M media as the chloro-complex. Depending on the acid concentration, the remaining elements are all partially extracted as xanthate complexes.     

Substoichiometric separation in activation analysis: extraction of co-ordinatively-unsolvated salts

The necessary conditions have been examined for the use of extraction of coordinatively-unsolvated salts for substoichiometric separations in activation analysis, especially the influence of interfering ions and of the concentration of the carrier. A study has been made of the substoichiometric extraction of halide ions, oxyanions and anionic metal complexes by means of the tetraphenylarsonium ion into chloroform and dichloroethane, and of the extraction of alkali metal ions into nitrobenzene with tetraphenylborate. Substoichiometric extraction can be combined with neutron-activation analysis for the determination of traces of iodine, caesium, rubidium, manganese, rhenium, chromium, thallium, gold, gallium and tantalum.     

Substoichiometric extraction of tantalum with diantipyrylmethane

Diantipyrylmethane is used for substoichiometric extraction of tantalum from 1—4M hydrofluoric acid into 1,2-dichlorethane. The selectivity of the method is good, niobium and antimony(V) being the main inteferences. The stoichiometric composition of the tantalum/diantipyrylmethane complex is 1:1. The method was usef for the determination of trace amounts of tantalum (0.52 ± 0.05 μ g^?1) in a lake sediment (Bodensee/Lake Constance) by neutron activation/μ-spectrometry. Tantalum was determined in niobium samples by an isotope dilution procedure after separation of the matrix on a polyurethane foam column loaded with diantipyrylmethane.     

Substoichiometric extraction of mercury with malonic anilide

Determination of mercury (II) by substoichiometric extraction with malonic anilide into a mixture of ether and MIBK is reported. The method has been applied in the estimation of the metal in industrial effluents.     

Kinetics of the nucleophilic substitution of benzyl-tributylammonium bromide with allyl,butyl, and benzyl chlorides and with benzyl acetate and benzyl ether

In this study, we investigated the kinetics of the nucleophilic substitutions, RX + (BzBu₃NBr) ← → RBr + (BzBu₃NX), where R = allyl, Bu and Bz, when X = Cl; and X = AcO and BzO when R = Bz. The forward and backward rate constants in addition to the activation energies for R = allyl and Bu were also determined. However, only the rate constants at 35°C were determined for the benzyl compounds with toluene as the solvent to reduce the reaction rate. Moreover, the effects of the structures of the groups R and the leaving groups X on the reactivity were compared. Results in this study can provide valuable information for future studies involving the phase transfer catalyzed displacements. © 1996 John Wiley & Sons, Inc.     

Substoichiometric exchange extraction of tantalum and gold with tetraphenylarsonium

The conditions for substoichiometric exchange extraction in the system have been investigated in order to establish the feasibility of substoichiometric separation of tantalum and its determination by activation.     

Combination and disproportionation reactions of allylic radicals with ethyl,propyl, and t-Butyl Radicals

1-Methylallyl, 1,1-dimethylallyl, 1,2-dimethylallyl, 1,3-dimethylallyl, 1,1,2-trimethylallyl, and 1-ethylallyl radicals have been generated in the gas phase at 20 ± 1°C by addition of H atoms, formed by Hg(6³P₁) photosensitization of H₂, to appropriate dienes. Their combination reactions with ethyl radicals have been studied and the relative reactivities of the reaction centers in each allylic radical determined. Similar measurements have been made for some combination reactions of n-propyl, i-propyl, and t-butyl with 1-methylallyl and 1,1,2-trimethylallyl radicals. The more substituted reaction centers are found to be the less reactive. In addition the self-combination and disproportionation of 1-methylallyl radicals has been investigated, as has cross disproportionation of each allylic radical with ethyl. The results establish a general pattern of reactivity for these radicals, which is interpreted primarily in terms of the effects of steric interaction during reaction.