Quinolinic acid as a reagent for the gravimetric and volumetric estimation of palladium

Summary Like -amino-picolinic acid, quinolinic acid behaves as a highly selective reagent for palladium with which it forms a complex of composition Pd(C₇H₄O₄N)₂. The complex being very stable is precipitated from solutions with an acidity of 0.25 N to a maximum p_H of 2.1 and thus is separated from all the common ions and other platinum metals except copper which, however, can be kept in solution in presence of EDTA. The palladium complex is either weighed after drying or dissolved in a standard potassium cyanide solution which is later back titrated with silver nitrate solution.     

Dehydroacetic acid as a reagent for the separation and gravimetric determination of copper(II), aluminium and beryllium

Dehydroacetic acid is proposed as a reagent for the gravimetric determination of copper(II), aluminium and beryllium at pH 3.0-6.0, 3.0-6.0 and 7.5-9.5 respectively. Copper is weighed as the complex Cu(C(8)H(7)O(4))(2). Aluminium and beryllium are weighed as Al(2)O(8) and BeO. The reagent is easy to prepare.     

Acetothioacetanilide as a gravimetric reagent for palladium, platinum and rhodium

Acetothioacetanilide, CH(3)CO . CH(2) . CS . NH . C(6)H(5) is found to be a very suitable gravimetric reagent for Pd(II), Pt(II) and Rh(III). The complexes [composition, M(C(10)H(10)NOS)(2); for M = Pd(II) and Pt(II), and M(C(10)H(10)NOS)(3)] are stable and can be weighed after drying at 105-110 degrees . Separation from base metals has been studied, and a structural interpretation made from DTA, TG and infrared data.     

N,N'-diphenyldithiomalonamide as a gravimetric reagent for nickel and cobalt

N,N'-Diphenyldithiomalonamide, (C₆H₆. NH. CS)₂CH₂, is found to be a very suitable gravimetric reagent for nickel(II) and cobalt(II). The complexes, of composition Ni(C₁₅H₁₃N₂S₂)₂ and Co(C₁₅H₁₃N₂S₂)₃, are stable and can be weighed after drying at 110°. Separation from base metals has been studied, and the structural interpretation is supported by DTA, TG, infrared and NMR data.     

Alizarin blue as a specific reagent for the gravimetric determination of copper

A new method for the gravimetric determination of copper was developed, based on the specific precipitation of copper alizarin blue from highly acid solutions. The determination can be carried out in very dilute solutions up to an amount of 2 mg of Cu. Copper can also be determined in alkali cyanide solution after demasking with formaldehyde.     

Sulfophenylanthranylic acid as a new reagent for palladium

The use of diphenyl reagents bearing electron-withdrawing substituents in catalymetric analysis was studied using sulfophenylanthranilic acid as an example. A selective catalytic effect of palladium(II) on the oxidation of sulfophenylanthranilic acid by cerium(IV) sulfate in a weakly acid solution was found. The reaction rate was studied as a function of component concentrations, solution acidity, and temperature. A procedure for determining palladium(II) was developed and tested using model mixtures and a KP-5 sample of complex composition.Translated from Zhurnal Analiticheskoi Khimii, Vol. 60, No. 2, 2005, pp. 144–148. Original Russian Text Copyright © 2005 by Burmistrova, Mushtakova, Nikonorov.     

N-Acetylacetone-anthranilic acid as a gravimetric reagent for copper(II)

N-Acetylacetone-anthranilic acid has been employed as a reagent for the gravimetric determination of copper(II). The solid copper(II) chelate formed possesses 1:1 metal-ligand stoichiometry and is found to exist as an unsolvated dimer. The complex has a magnetic moment of 1.88 B.M. at 298 K. A non-planar dimeric structure is suggested to explain the observed facts.     

Gravimetric determination of palladium with quinolinimide as a reagent

Summary Quinolinimide which is found to be a selective reagent for palladium forms a complex of the composition Pd(C₇H₃O₂N₂)₂. The reagent quantitatively precipitates palladium from solutions of p_H 0.5 to 2.5 in presence of common ions as well as platinium metals, except tin which, however, can be kept in solution by complexing with citric acid. The palladium complex being stable up to 307° C can be directly weighed.

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Zusammenfassung Chinolinimid wird als selektives Reagens für Palladium vorgeschlagen. Bei p_H-Werten zwischen 0,5 und 2,5 kann Palladium quantitativ in Form des Komplexes Pd(C₇H₃O₂N₂)₂ gefällt werden, wobei die meisten anderen Ionen, auch die der Platinmetalle, in Lösung bleiben. Zinn stört, kann aber mit Citronensäure maskiert werden. Der Palladiumkomplex ist bis 307° C stabil und kann direkt ausgewogen werden.

     

Nitroso-R-salt as a reagent for the determination of palladium (II)

Summary A procedure for the determination of palladium with nitroso-R-salt is presented. The sensitivity is 0.068 g/cm².

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Zusammenfassung Es wird ein Verfahren von zur Bestimmung Palladium mit Nitroso-R-Salz beschrieben, dessen Empfindlichkeit 0,068 g/cm² beträgt.

     

Prochlorperazine bismethanesulfonate as a new reagent for the spectrophotometric determination of palladium

A simple, rapid, and selective method for the determination of palladium is described. The orange-red palladium(II)-prochlorperazine bismethanesulfonate complex in the presence of hydrochloric acid-sodium acetate buffer exhibits maximum absorbance at 480 nm with a molar absorptivity of 4.32 × 10³ liters mol^?1 cm^?1. The sensitivity of the reaction is 24.62 ng cm^?2. The system obeys Beer's law over the concentration range 0.4–20 ppm of palladium with an optimum concentration range of 1–19 ppm. The apparent stability constant of the complex is found to be log K = 5.3 ± 0.1 at 27 °C. The effects of pH, time, temperature, order of addition of reactants, reagent concentration, and interferences from various ions are reported. The proposed method offers the opportunity to carry out the determination at room temperature without the need for an extraction step. The method is also found to be suitable for the determination of palladium in jewelry alloy.     

o-Hydroxyacetophenone thiosemicarbazone as a reagent for the rapid spectrophotometric determination of palladium

o-Hydroxyacetophenone thiosemicarbazone has been synthesized and employed as a new reagent for the spectrophotometric determination of palladium(II), which forms two complex species with it in aqueous dimethylformamide at pH 6.0, these having 1:1 and 1:2 metal-ligand ratios. The Job and molar-ratio plots have an unusual shape that is due to the stepwise conversion of the 1:1 complex into the 1:2 species. The molar absorptivity at 370 nm is 9 x 10(3) l.mole(-1).cm(-1). Beer's law is obeyed over the range 0.42-10.6 mug/ml palladium.     

Oximidobenzotetronic acid — a sensitive spot test reagent for iron(II), cobalt(II) and copper(II)

Summary Oximidobenzotetronic acid is suggested as a sensitive spot test reagent for iron(II), cobalt(II) and copper(II) in the presence of commonly occuring cations.

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Zusammenfassung Oximidobenzotetronsäure (3-Ntroso-4-hydroxycumarin) wird als empfindliches Tüpfelreagens zum Nachweis von Fe(II), Co(II) und Cu(II) in Gegenwart anderer Kationen vorgeschlagen.

     

Trichlorophenoxyacetic acid as a reagent for the determination of Thorium

2:4:5-trichlorophenoxyacetic acid has been successfully used for the determination of thorium. It has been proved to a better reagent for thorium than 2:4-dichlorophenoxyacetic acid as it produces quantitative precipitation of thorium at a considerably lower pH value and can separate Th from a number of common elements, such as Ca, Ba, Sr, Zn, Co, Ni, Ti, U, etc. and cerite earths more effectively. Zr and Fe interfere, but iron may be removed by a convenient method. Direct weighing may be applicable for the estimation of thorium within the limites of experimental error,     

Thenoyltrifluoroacetone as a reagent for cobalt

Summary An indirect method is proposed for the determination of cobalt (II) with 2-thenoyltrifluoroacetone at the milligram level. The orange cobalt-TTA chelate can be quantitatively precipitated over the p_H range 4.0–8.0. It is dissolved in acid and estimated as cobalt sulphate. Cobalt(II) can be estimated in presence of silver, mercury(II), strontium, iron(III), chromium (III), thorium, zirconium, uranium, citrate and tartrate. The method is reproducible to within ±1 per cent.     

Benzeneacetaldehyde-4-hydroxy-alpha-oxo-aldoxime as a new analytical reagent for the spectrophotometric determination of cobalt

Benzeneacetaldehyde-4-hydroxy-α-oxo-aldoxime is proposed as a new sensitive and selective reagent for the spectrophotometric determination of cobalt. The reagent reacts with cobalt in the pH range 8.6–9.4 to form a yellow colored 1:3 chelate which is very well extracted in chloroform. Beer's law is obeyed in the concentration range 0.05–1.3 μg ml⁻¹ cobalt. The molar absorptivity of the extracted species is 2.746×10⁴ l mol⁻¹ cm⁻¹ at 390 nm. The proposed method is highly sensitive, selective, simple, rapid, accurate and has been satisfactorily applied for the determination of cobalt in synthetic mixtures, pharmaceutical samples, biological samples and alloys.