Showing papers in "Talanta in 1968"

TL;DR: The presence of hexamethyldisiloxane greatly accelerates the diffusion separation of fluoride, making it possible to recover > 97% of radioactive fluoride in one hour at room temperature.

TL;DR: The program, which employs the non-linear least-squares method, may be used to calculate equilibrium constants for hydrolysed metal ions, protonated ligands, and simple, Protonated, Hydrolysed, polynuclear, and mixed complexes.

TL;DR: The fluorescence of a Morin-thorium complex provides a more sensitive fluoride reagent than has been previously used and has immediate stability and a linear response to fluoride up to 50% reduction in fluorescence.

TL;DR: A simple and accurate titrimetric determination of calcium in the presence of larger amounts of magnesium is proposed, and has been successfully applied to the determination ofcium in sea-water with an error less than 0.1%.

TL;DR: A review is given of the use of flavones as spectrophotometric, fluorimetric and gravimetric reagents for metals and a few non-metals.

TL;DR: The usefulness of X-ray fluorescence analysis for the determination of bromine in soil and plants is demonstrated by comparing the results with those obtained by activation analysis.

TL;DR: With the possible exception of the C3 chondrites, the mean abundances for each petrologic type within a given chemical group are identical.

TL;DR: The nature of complexes between various o,o'-dihydroxyazo dyes and metal ions, and their applications in polarographic chemical analysis, are described and discussed.

TL;DR: Measurements made with a combination of glass and lanthanum fluoride membrane electrodes in solutions which are strongly acid but varying in ionic strength have been used to calculate the dissociation constant of hydrogen fluoride and to validate the response of the latter electrode in strongly acidic media containing fluoride ions.

TL;DR: The electron capture detector has been used to measure ultra-trace quantities of beryllium separated as beryLLium(II) trifluoroacetylacetonate by gas Chromatographic techniques, and none of the fifteen ions studied interferes appreciably.

TL;DR: Spectrophotometric measurements indicate that true ternary complexes are formed with well defined structures and that the changes in absorption spectra produced are not due to simple adsorption of the binary metal-dye complex onto micellar aggregates.

TL;DR: Tritium tracer is used to estimate completeness of water absorption and the results serve to evaluate the ratio of tritium and water distribution coefficients for use in collateral determinations of water solubility by simple liquid-liquid distribution.

TL;DR: The current literature is reviewed with the intention of facilitating the characterization of unknown materials derived from bivalent metal halides.

TL;DR: A review of methods proposed for the analysis of antioxidants in polymeric materials, cast in the form of a step-by-step examination of the problems involved in any scheme of analysis, with a critical appraisal of the published procedures designed to overcome them.

TL;DR: The primary and secondary combination zones of an air-acetylene flame have been separated by a stream of nitrogen flowing parallel to the flame to prevent access of atmospheric oxygen to its base, and the flame is very stable over a wide range of fuel-air mixture strengths, and organic solvents may be aspirated without difficulty.

TL;DR: A procedure for the separation of gold from precious metal concentrates, based on its extraction by "dibutyl carbitol", is described and tests have shown that recovery of the element is essentially quantitative.

TL;DR: Reactions between a complex AB and a third component C do not always proceed by a displacement mechanism governed by the energy difference of the chemical bonds A-B and A-C.

TL;DR: The titrimetric determination of glucose, fructose, mannose, galactose, arabinose, xylose and sucrose with potassium ditelluratocuprate(III) is described and pentoses and hexoses consume 20 and 24 equivalents of copper( III) per mole respectively.

TL;DR: 4-Chloro-o-phenylenediamine reacts with selenous acid at pH 0-1 to form 5-chloropiaselenol, which is then extracted into 1 ml of toluene, and the peak height selenium is determined.

TL;DR: From the exchange constants determined, the extraction constants of metal diethyldithiocarbamates have been calculated and the influence of organic solvents on the exchange reaction of zinc diethyldaocarbamate with dithizone has been investigated.

TL;DR: A method is described for the determination of palladium down to 4ppb, platinum down to 10 ppb and rhodium down to 5 ppb in 15 g of sample, which requires much less sample handling than most published methods for these elements.

TL;DR: Procedures are described for the accurate determination of silver and mercury(II) (2-10 x 10(-7)M) in the presence of each other and of most other metals.

TL;DR: A long path-length diffusion flame is also particularly useful in atomic-absorption measurements because it absorbs very little radiation in the far ultraviolet region and gives an abundance of arsenic atoms.

TL;DR: None of the new compounds proved to be superior to chromogenic reagents currently in use, but the results are of interest in designing new chromogens.

TL;DR: A study of CN spectra and the zones of persistence of free atoms and ofMetal oxide species suggests a mechanism of free atom production within the cyanogen zone whereby the removal of oxidizing radicals by CN promotes dissociation of metal oxide species previously formed in the primary zone of the flame.

TL;DR: A rapid spectrophotometric method for the determination of low levels of cobalt(III) with 2,2 -dipyridyl ketoxime with 3:1 water-soluble complex shows to be widely applicable; it is simple, convenient and reproducible.

TL;DR: The anion-exchange characteristics of the platinum metals and gold in hydrochloric acid media are described and the conditions most suitable for quantitative separation are discussed.

TL;DR: A review of the literature on the uranium content of sea-water finds that uranium in seawater is low, but the content of other minerals, such as cadmium, has been found to be high.

TL;DR: A new method based on the substoichiometry principle has been developed, where instead of substoicoichiometric amounts of chelating agent, substoicometrical amounts of aqueous solution of a competing metal are used.

TL;DR: The uranyl complexes of EDTA have been studied by potentiometry ; stability constants of the 1:1 and 2:1 (metal to ligand) chelates have been determined, as well as the respective hydrolysis and polymerization constants.