The polarographic determination of indium in zinc-base alloys : The determination of indium in zinc and in zinc alloys of low aluminium content

Studies of the application of an 8-hydroxyquinoline extraction and of a zinc oxide “collection” procedure for the separation of trace amounts of indium from zinc alloys are described and discussed. A combination of radio-chemical and polarographic determination were employed for this work. A polarographic method for the determination of indium in zinc and in zinc alloys of low aluminium content is presented     

The polarographic determination of aluminium in zinc-base die-casting alloys

A procedure for the direct polarographic determination of aluminium is described, with particular reference to zinc-base die-casting alloys. Interfering elements are removed by electrolysis of a solution of the alloy in a mercury-cathode cell. The solution is polarographed at a carefully controlled pH in a supporting electrolyte of magnesium chloride and sodium sulfate of appropriate concentration. The precision and accuracy of the method are shown to be satisfactory by the analysis of standard samples from three different laboratories.     

Extraction-photometric determination of indium in zinc-base alloys with bromopyrogallol red

The extraction-photometric determination of indium at the 5 p.p.m. level in highpurity zinc and zinc-base alloys is described. After a preliminary separation of indium by isopropyl ether extraction from hydrobromic acid medium, indium is determined by extraction into benzyl alcohol of its complex with bromopyrogallol red at pH 9.0. It is shown that 2:1, 1:1 and 1:2 complexes can be formed in aqueous and water-ethanol media; the 1:3 complex reported earlier was not found. The composition of the complexes extracted into benzyl alcohol from aqueous solutions at pH 6.5 and 9.0, was found to be 1:2.     

The polarographic determination of indium in zinc-base alloys : General introduction. the application of the linear sweep cathode ray polarograph

The problems relating to the polarographic determination of trace amounts of indium in zinc and zinc-base alloys, especially mazak, are discussed and literature relating to the extraction and polarography of indium is briefly summarised. A method for the determination of indium using the linear-sweep cathode ray polarograph is presented and certain aspects are discussed.     

The polarographic determination of lead in tin-base alloys

A polarographic method for the determination of lead in tin-base alloys is described For alloys containing more than 2% lead no separations are necessary; in those with a lower lead content, most of the copper present must be removed as cupric oxide Results are exact: ±4% of the amount of lead present.     

The polarographic determination of chromium in aluminum alloys

A convenient polarographic method for the determination of 0.1–0.5% of chromium in aluminum alloys is described. The alloy is dissolved in a bromine water-sodium hydroxide mixture; after suitable treatment, chromate is determined polarographically. Specific directions for the simultaneous running of a blank experiment are given ; this provision greatly improves the accuracy of the results obtained.     

Spectrophotometric determination of thallium in zinc and zinc-base alloys with iodoacetic acid and hexamethylenetetramine

Thallium(III) forms a ternary complex of yellow colour with iodoacetic acid and organic bases, especially hexamethylenetetramine. The complex is soluble in water and various organic solvents. Zinc, copper, cadmium and iron do not form complexes with these reagents, so that a spectrophotometric determination of thallium in zinc and its alloys is possible. The limit of detection is 15 gg^–1, the molar absorption coefficient about 2000 mol^-1l^-1cm^-1.     

The polarographic determination of thallium

A polarographic method is described for the determination of thallium in sodium triphosphate supporting electrolyte. The incorporation of 0.1% camphor in the electrolyte displaces the cathodic steps of many interfering ions, e.g., lead(II), copper(II), iron(III) and bismuth(III) to a more negative potential (1?.0 V), well away from the thallium step which remains unaffected.     

The differential pulse polarographic determination of trace amounts of tin and its application to zinc-aluminium alloys

A differential pulse polarographic procedure for the determination of 0.001-0.02% of tin in zinc-aluminium alloys is described. The tin is first separated from interfering elements such as copper and lead by homogeneous co-precipitation with aluminium succinate. The tin is determined polarographically in a 1M hydrochloric acid + 4M ammonium chloride electrolyte. After the tin has been masked with alkaline citrate a second polarogram is recorded to ascertain whether residual lead is present and, if so, a correction is applied.     

The polarographic behavior and determination of glafenine

Glafenine was found to be reducible at the dropping-mercury electrode (DME) in Britton-Robinson buffer (BRB) over the whole pH range. In the alkaline range, a well-defined cathodic wave was produced. The wave was characterized as being diffusion-controlled and partially affected by adsorption phenomena. A method was proposed for the determination of glafenine in tablets and the results obtained were satisfactorily accurate and reproducible.     

The spectrochemical determination of indium in cassiterite

In order to determine the indium content of cassiterite specimens, a spectrochemical method, using tin as internal standard and the cathode-layer carbon arc, has been employed. The precision of the procedure is approximately 5 %.     

The polarographic determination of isopropenyl esters in aqueous solution

Both mercuration and bromination have been used for the polarographic analysis of isopropenyl esters in aqueous solutions. For mercuration, no disadvantages were found in comparison with the established methods [4,5] for the estimation of vinyl esters in methanol, due to either the lower rate of mercuration [5,22] or the expected lower stability of the depolariser formed in aqueous solution, the hemiacetal mercuric acetate addition product. At concentrations below 10^?2 mol l^?1, acetone did not interfere [38] with the determinations.     

Solvent extraction—flame spectrometric methods for the determination of indium in aluminium alloys

Atomic absorption and atomic emission methods for determining trace and minor amounts of indium in aluminium alloys are described. They involve the separation of indium from the aluminium matrix by extraction of indium diethyldithiocarbamate from hydrochloric acid at pH 3, and determination by emission at 451.13 nm or absorption at 303.9 nm in the extract; a nitrous oxide—acetylene or air—acetylene flame is used.     

Indirect polarographic determination of arsenic

A method for determination of arsenic(V) in the range between 1 x 10(-7) and 1.2 x 10(-6)M has been developed. These levels are reached by means of the multiplication factor yielded by use of 12-molybdoarsenic acid and the great sensitivity of polarographic determination of the Mo(VI) in the heteropoly acid. The procedure has been successfully applied to determination of arsenic in copper alloys, after selective extraction of phosphorus.     

Sine-wave polarographic determination of small amounts of indium in the presence of large amounts of cadmium,lead or tin

The sine-wave polarographic determination of small amounts of indium in the presence of large amounts of cadmium, lead or tin was investigated. The determination of indium in cadmium was possible down to 0.01 % in 1 M potassium iodide at pH 2, the determination of indium in lead was possible down to 0.02 % in 1 M potassium chloride at pH 2, and the determination of indium in tin was possible down to 0.3 % in 1 M hydrochloric acid and down to 0.2 % in 2 M perchloric acid with 0.5 M sodium chloride.