Masaaki Yanagisawa

Trace analysis by flameless atomic-absorption spectrometry

The operating conditions of an atomic-absorption system based on flameless atomization have been investigated for trace analysis for Al, Cr, Cu, Fe, Mg and Mn. The sample solution on a tantalum strip was atomized by electrical heating in an inert atmosphere within an absorption chamber. This technique allows the use of small sample sizes and results in a higher sensitivity than that with the conventional flame technique. Some interference effects and applications were investigated.

Atomic absorption spectrophotometry of antimony

Abstract The atomic absorption of antimony in combination with extraction of the chloride complex provides a suitable determination of antimony in various materials. The effect of variables on antimony absorption and the extraction of antimony were studied. Procedures for small amounts of antimony in metallurgical products and synthetic fibers are given.

Determinations of traces of calcium in phosphoric acid and its salts by atomic-absorption spectrometry.

A method for the determination of traces of calcium by atomic-absorption spectrometry after extraction into an organic solvent, has been investigated for the determination of traces of calcium in phosphoric acid and its salts. Calcium is extracted as the hydroxy-quinolate complex, the extract is introduced into the flame, and the calcium atomic-absorption is measured. The effects of pH, concentration of reagent, and diverse ions on the calcium extraction were investigated.

Determination of magnesium by atomic-absorption spectrophotometry after extraction

Abstract A method for the determination of magnesium by atomic-absorption spectrophotometry, after extraction into an organic solvent, has been developed. Magnesium is extracted as an 8-hydroxyquinolate or 8-hydroxyquinaldate complex into methyl isobutyl ketone. The extract is introduced into the flame and the magnesium absorption measured. The 8-hydroxyquinolate extraction method serves to determine trace amounts of magnesium in alkali products such as purified brine, sodium carbonate and sodium bicarbonate. The 8-hydroxyquinaldate extraction method serves to determine small amounts of magnesium in aluminium metal and aluminium alloys.

Spectroscopic study of atomization processes and inter-element effects on the flame emission of chromium and iron in an air—acetylene flame

Abstract Emission spectroscopy is applied for characterization of reactions occurring in air—acetylene flames normally used for atomic absorption spectrometry. Inter-element effects on the emissions of chromium and iron are discussed. Two atomic emission lines with different upper energies and a molecular emission line of the diatomic oxide MO are compared for determination of the excitation temperature and the degree of atomization in fuel-rich and lean flames. The reductive power of the fuel-rich flame is essential for atomization of chromium salts. Inter-element effects by iron can be attributed to the formation of refractory oxides, and to mutual catalytic oxidation.

Atomic absorption spectrometry of traces of tri- and hexavalent chromium

SummaryAtomic absorption spectrometry combined with extraction is described for the determination of tri- and hexavalent chromium. The chromium diethyldithiocarbamate chelate was used for chromium (VI), whereas hydroxyquinolate or thenoyltrifluoroacetonate chelate for chromium(III). The method is rapid and precise.ZusammenfassungExtraktion und darauffolgende Messung der Atomarabsorption wurden zur Bestimmung von drei- und sechswertigem Chrom verwendet. Die Chelatverbindung mit Diäthyldithiocarbamat wurde für Chrom(VI), der Chelatkomplex mit Hydroxychinolin oder Thenoyltrifluoraceton für Chrom(III) verwendet. Das Verfahren ist rasch und genau.

Flameless atomic absorption spectrometry of antimony

Abstract Flameless atomic absorption spectrometry of antimony has been investigated with a carbon rod device. Antimony may be determined in solution at a level of 10 -10 g with a sample volume of 0.5 μl. Optimal conditions and interferences are described. Matrix effects on antimony necessitated a preliminary solvent extraction of the chloride complex from hydrochloric acid solution containing nitrite with methyl isobutyl ketone. The determination of antimony in metallurgical samples was shown to be satisfactory.

Some interferences in atomic-absorption spectrometry and extraction of iron and copper.

The effect of complexing agents on the atomic-absorption spectrometry of iron and copper extracts was investigated Thiocyanate complexes gave a marked depression of absorption by iron and copper, especially in fuel-rich flames. Chloride, diethyldithiocarbamate and hydroxyquinoline complexes of iron behaved alike, but differently from the thiocyanate complex.

Separative column atomizer (SCA) for direct analysis by atomic absorption spectrometry. GC separation characteristics

Abstract An improved separative column atomizer (SCA) usable at higher temperatures up to 1350°C has been constructed. Emphasis in this article is on the GC characteristics of an improved separative column atomizer (SCA) module to reduce the interferences caused by background absorption that is often unavoidable in direct analysis of practical samples. By direct AAS analysis, mercury in some organic samples has been successfully determined without background absorption due to non-atomic species resulting from the sample matrices. In the direct atomization of samples in EDTA matrix, however, complete elimination of the background absorption was not possible. Nevertheless, GC separation found in the improved SCA was effective in the measurement of the AA peak free from molecular absorption. Evidences of the GC separation were also given by the analysis of effluent gases.

Separative column atomizer for the direct determination of trace amounts of volatile elements by atomic absorption spectrometry

Abstract A novel atomizer effective for direct analysis was developed using a new type separative column atomizer (SCA) module. The SCA module incorporated an atomization part, a separation column and/or reaction column part and observation windows for atomic spectroscopic measurement. This module was applied to the direct analysis of trace amounts of mercury and cadmium in practical samples. No background absorption was observed on the thermal decomposition of synthesized samples in a starch matrix and human hair at the wavelengths of the analytical lines of Hg and Cd. The effectiveness of the technique for the determination of elemental compositions is evaluated.