- Full text PDF available (1)
- This year (1)
- Last 5 years (1)
- Last 10 years (1)
Journals and Conferences
An experimental design is proposed for the verification of the accuracy and precision of an analytical method by its application to certified reference materials.
A method has been developed to determine sulphate and thiosulphate in small amounts of the oxidation products of sulphide minerals. The sample is treated with ammonium sulphide solution to promote ion-exchange between sulphide ion and the sulphur-bearing anions of the oxidation products. Sulphate is determined alone and then all other sulphoxy anions are… (More)
A statistical design is proposed for assessing the accuracy of an analytical method by its application to a certified reference material in an interlaboratory programme. The validation of accuracy is based on the difference between the certified value and the overall mean of the test programme and is linked to the concept that below a certain limit this… (More)
The end-point for the titration of EDTA with Cu(II), as measured by a Cu(II)-selective electrode, varies with pH and temperature. Moreover, the effect of pH and temperature on the behaviour of this electrode differs according to whether fluoride is present. As a consequence, the determination of aluminium in zinc-aluminium alloys by the Freegarde and Allen… (More)
The history of two lead-zinc (sulphide) reference ores is presented to show quantitatively the serious effects of ambient oxidation on unprotected samples. This study should serve as a warning to the users and producers of sulphide-bearing reference ores and concentrates. Suggestions are given for overcoming or diminishing the oxidation problem.
The methods employed in the chemical phase-analysis of rocks, ores and their treatment products are reviewed. An attempt has been made to be critical, selective and thorough in the choice of methods available in the literature, in order to provide a convenient manual for workers interested in this aspect of analytical chemistry.
A pseudo-kinetic method has been developed for determining the ferrous and ferric iron in the water-soluble oxidation products of pyrrhotite, pyrite and chalcopyrite, and ores and concentrates containing them. Two determinations are required for each material. In one, the total iron is determined with 1,10-phenanthroline after reduction to Fe(II). In the… (More)
Two forms of a DNA polymerase have been purified from microplasmodia of Physarum polycephalum by poly(ethyleneimine) precipitation and chromatography on DEAE-Sephacel, phosphocellulose, heparin Sepharose, hydroxyapatite, DNA-agarose, blue-Sepharose. They were separated from DNA polymerase alpha on phosphocellulose and from each other on heparin-Sepharose.… (More)
A new technique has been developed to determine trace quantities of elemental sulphur in minerals and ores. After separation from the sample by sublimation, the sulphur is determined spectrophotometrically in ethanol. Sulphide, sulphite, sulphate and thiosulphate do not interfere. The effect of the presence of xanthate or dixanthogen is discussed briefly.
Tin is stannite-kesterite and as cassiterite in a tin-bearing ore can be determined by the selective decomposition of the stannite-kesterite phase with a mixture of sodium nitrate and acetic acid.