The detection of potassium sulfate in excess of potassium pyrosulfate

X-Ray diffraction, infrared, and raman spectroscopic methods were investigated for the detection of K₂SO₄ in excess of K₂S₂O₇ in solid solutions.The X-ray diffraction lines of K₂SO₄ were found to be overlapped by the diffraction pattern of K₂S₂O₇ and infrared studies indicated that K₂SO₄ absorption bands corresponded to regions of strong absorption in K₂S₂O₇. The detection of sulfate could not be carried out by the X-ray diffraction and infrared methods. However, the raman method indicated that a strong and narrow K₂SO₄ band at 981 cm^?1 could unambiguously be used for the detection of sulfate in solid solutions of K₂SO₄ in K₂S₂O₇, as pyrosulfate showed no absorption around this band.     

Yttrium 8-hydroxyquinolinates

The preparation of two yttrium 8-hydroxyquinolinates, one by conventional means and the other by precipitation from homogeneous solution, was investigated. Analytical data indicated that the complex prepared conventionally corresponds to Y(C₉H₆NO)₃, and the complex prepared by precipitation from homogeneous solution corresponds to Y(C₉H₆NO)₃·C₉H₇NO. Thermogravimetric analyses, infrared, ultraviolet-visible and diffuse reflectance spectroscopic studies were carried out on both compounds. They were shown to be very similar structurally.     

Solution thermochemistry of diethyldithiocarbamato-iron(III)

The enthalpy change (303 K) for the standard state solid phase complexation reaction

is derived using conventional solution calorimetric techniques (ΔH°_R=?82.7±2.0 kJ mol^?1. Knowlege of ΔH°_R is a necessary pre-requisite for the future derivation of the FeS thermochemical bond energy.     

Adsorptive stripping voltammetry of some trace elements in biological samples. I. Cadmium and zinc

A study of the adsorptive stripping voltammetry of cadmium and zinc is reported in which ligands containing sulphur donor atoms were examined. This type of ligand showed good adsorptive behaviour and strong metal complexation. It was found that the ligand 2,5-dimer-capto-1,3,4-thiadiazole (DMTD) was very suitable for the determination of cadmium and zinc using this technique.The method was applied to the direct determination of these metals in biological samples using benzyl trimethylammonium methoxide as digesting solvent for the samples.     

FTIR Emission Spectra, Molecular Constants, and Potential Curve of Ground State GeO

Extensive new high-temperature, high-resolution FTIR emission spectroscopy measurements for the five common isotopomers of GeO are combined with previous diode laser and microwave measurements in combined isotopomer analyses. New Dunham expansion parameters and an accurate analytical potential energy function are determined for the ground X1Sigma+ state. Copyright 1999 Academic Press.     

The oscillographic polarography of noble metal complexes

The polarographic behaviour of complexes of the noble metals was studied by oscillographic polarography. A method was developed for the polarographic determination of copper, gold and palladium; silver and nickel do not interfere. Applications to the analysis of dental alloys proved successful.     

The separation and determination of niobium and tantalum by partition chromatography

A procedure is outlined for the separation and determination of niobium and tantalum by paper chromatography. A mixture of methyl isobutyl ketone and hydrofluoric acid was used as solvent and the metals were detected by means of 8-hydroxyquinoline. The minimum amount of each element detectable is 20 μg.

The procedure was applied successfully to the quantitative determination of small amounts of niobium and tantalum in a steel.     

A thermogravimetry/differential thermal analysis,evolved gas analysis and pyrolysis/gas chromatography—mass spectrometry study of tetrakis (diethyldithiocarbamato)tin(IV)

The thermal decomposition of tetrakis(diethyldithiocarbamato)tin(IV) has been studied by TG/DTA, EGA and P/GC-MS techniques. From the P/GC-MS analysis, it is apparent that the denticity of the dithiocarbamate ligand influences the mechanism of decomposition. Initially, the monodentate ligands decompose by a radical mechanism to form tetraethylthiuramdisulphide which decomposes further into carbon disulphide and diethylamine. The intermediate formed, bis(diethydithiocarbamato)tin(II), decomposes in two different ways. The bidentate ligands decompose with the liberation of carbon disulphide and tetraethylthiourea, whereas the monodentate ligands, formed as a result of the high temperatures, decompose to produce S-ethyl N,N-diethyldithiocarbamate and ethylisothiocyanate. The overall thermal decomposition mechenism of tetrakis(diethyldithiocarbamato)tin(IV) is complex and the primary decomposition involved both ionic and radical recombination reactions.