Molecular emission cavity analysis: stimulation of metal halide emissions

Some metal halides (Mn, Co, Ni, Pb and possibly Fe) emit metal(I) halide spectra from the MECA cavity in hydrogen-nitrogen-air flames, in contrast to their behaviour in conventional aspiration flame systems. However, the emission intensity is too weak to provide sensitive analytical applications. Indium halides give intense emissions by either the MECA or aspiration method. Halogenated organic compounds give intense CH and C₂ emissions. Cadmium halides give only an intense atomic emission. Sensitive methods for halides, indium, cadmium and organic compounds are thus possible. Mercury (II) halides and metal fluorides give no measurable emission in the cavity method.     

Determination of magnesium in iron by atomic absorption spectrophotometry

An atomic absorption spectrophotometric method for the determination of 0.001–0.10% magnesium in irons has been proposed. After suitable dissolution of the sample, 1500 p.p.m. of strontium is added to suppress aluminium interference and the solution is atomised in an atomic absorption spectrophotometer. The method is rapid, has high sensitivity, is free from interference and no preliminary separations are required.     

A wet-combustion method for the determination of chlorine in coals

Chlorine in coals can be determined by wet-combustion with sulphuric acid in the presence of potassium dichromate and silver sulphate. The liberated chlorine is absorbed in hydrogen peroxide and after treatment with mercuric oxycyanide is determined acidimetrically. The method is simple, fairly rapid and should be suitable for multiplicate analysis. The results agree well with those given by two independent methods of analysis, i.e. incineration with Eschka mixture followed by the Volhard titration, and the high temperature combustion method.     

The microanalysis of fluorine-containing organic compounds. II. the determination of fluorine

Summary The compound is decomposed by fusion with metallic sodium or potassium in a nickel bomb of special design, and the fluorine is titrated with thorium nitrate solution. Several modifications of this titration procedure were first examined as a means of completing the determination, but only one was found suitable, i. e. back-titration of a comparison solution with a standard sodium fluoride solution.When nitrogen and sulphur, which form cyanide and sulphide ions, are present, the procedure has to be modified slightly to overcome their interference.

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Zusammenfassung Organische Fluorverbindungen werden durch Schmelzen mit metallischem Natrium bzw. Kalium in einer Nickelbombe besonderer Konstruktion zerstört und das Fluor mit Thoriumnitratlösung titriert. Einige Modifikationen dieses Titrationsverfahrens wurden zunächst geprüft, aber nur eine davon erwies sich endgültig als für die Bestimmung geeignet: die Rüektitration einer Vergleichalösung mit einer Standardlösung von Natriumfluorid.Bei Gegenwart von Stickstoff und Schwefel bilden sich Cyanidbzw. Sulfidionen, deren störender Einfluß durch eine kleine Abänderung des Verfahrens ausgeschaltet werden muß.

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Résumé Les composés organiques fluorés sont décomposés par fusion avec le sodium métallique ou le potassium dans une bombe de nickel de construction spéciale et le fluor est titré avec le nitrate de thorium en solution. Plusieurs modifications de ce mode de titrage furent d'abord examinées pour terminer le dosage, mais un seul fut trouvé convenable, le titrage par retour d'une solution de comparaison avec une solution de fluorure de sodium.Quand l'azote et le soufre qui forment des ions cyanhydriques et suifhydriques sont présents, le procédé doit être légèrement modifié afin d'empêcher leur interférence.

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The paper byR. Belcher andR. Goulden, Mikrochem.37, 679 (1951) is considered as Part I of this series.     

Reservoir storage and containment of greenhouse gases

This paper deals with the problem of disposal of industrial waste greenhouse gases (CO₂) into deep reservoirs. The simulator TOUGH2 was used to model the injection of 100 kg/s of CO₂ for 10 years into an aquifer 3 km deep with the object of evaluating the long-term storage prospects for this gas. Depending on the permeability structure above the injection point, some gas may escape to the surface. In the most favourable case, all of the gas dissolves into the water, and the resulting dense fluid settles in the aquifer over several thousand years. Consequently, underground storage provides a promising sink for reducing CO₂ emissions to the atmosphere.     

Early development of atomic absorption spectrometry in the Australian steel industry

The early development of atomic absorption spectrometry in the Australian steel industry is described. Some of the early difficulties of application are recorded, together with responsive developments by the Commonwealth Scientific and Industrial Research Organisation (CSIRO) to overcome them. Aspects of procedures developed for some alkaline earth and transition elements are described, together with an indication of the resultant substantial improvements in the operation of ferrous analytical laboratories.     

A knife-edge measurement of the beam profile of STXM 5.3.2.2 using a focussed ion beam milled metallic glass

We present a simple knife-edge measurement of the STXM 5.3.2.2 synchrotron X-ray beam width. The knife edge was constructed by ion beam milling a metallic glass alloy consisting of 60% gold, 20% nickel and 20% hafnium and was determined to be well-defined to within 2 nm by TEM. An asymmetric beam profile of 120 nm FWHM in the vertical direction and 150 nm FWHM in the horizontal direction was determined and was observed to depart from the expected Airy function profile.     

Colourimetric Carboxylate Anion Sensors Derived from Viologen‐Based Receptors

A series of tri‐ and tetrapodal viologen‐based anion receptors showing a colourimetric response to carboxylates, such as acetate, have been synthesised. Alteration of the anion binding sites allows for binding site competition within a receptor. This results in a delayed colourimetric response for urea derivatives compared with pyridinium systems because the anions are initially bound to the periphery of the receptor, away from the viologen unit. DFT calculations and experimental measurements allow the colour change to be assigned to an anion–receptor charge‐transfer process, facilitated by the exceptionally low reduction potential of the cationic host compounds. Evidence for electron transfer to give the viologen radical cation is also seen in some cases.