Toshihisa Maruta

Simultaneous determination of fluorine, chlorine and bromine in cement with ion chromatography after pyrolysis

A rapid method for simultaneous determination of fluorine, chlorine and bromine in cement with ion chromatography after pyrolysis was proposed for routine quality control analysis. The elements were separated from cement sample by pyrolysis, and were subsequently determined with ion chromatography. A pyrolysis method was investigated for the separation of micro amounts of these elements from cement. Total time taken to determine these elements is about 45 min including 25 min for the pyrolysis and 18 min for ion chromatography. The results of recovery tests ranged 95% or above. The limits of detection for F, Cl and Br are 0.2, 0.3 and 0.5 mg kg(-1), respectively. The method was successfully applied to the simultaneous determination of F, Cl and Br in commercial ordinary Portland cements.

Determination of trace amounts of chromium by atomic absorption spectrometry with a tantalum filament atomizer

Abstract The sample solution containing chromium was vaporized and atomized from a tantalum filament by electrical heating into an argon stream within an absorption chamber. The interference of various metals on the atomic absorption spectrometry of chromium was investigated. Interferences were minimized by using a high filament temperature. The flameless atomizer was used for the determination of chromium in steel at a filament temperature of 2150°; with the steels investigated no matrix effect was observed, and the accuracy and precision were satisfactory.

Interferences of acids in atomic absorption spectrometry with a tantalum filament atomizer

Abstract The interferences of hydrochloric, perchloric, nitric and phosphoric acids on the flameless atomic absorption spectrometry of copper, iron and chromium have been investigated. The mechanism of the acid interferences is discussed. The interferences depend on the acid used, the elements, and the power levels supplied to the filament. The interferences were minimized at high power supplied to the filament with the exception of the effect of phosphoric acid on copper absorption.

The flameless atomic absorption spectrometric determination of aluminum with a carbon atomization system

Abstract The atomic absorption spectrometry of aluminum with a carbon tube atomizer is described, with particular reference to the heating cycle, argon flow rate and amplifier time constant. Interferences are eliminated by pre-atomization heating or with a hydrogen-argon-entrained air flame. Under optimal conditions, the sensitivity (1 % absorbance) is 5·10 −11 g, and the relative standard deviation is 2.3 for 2.5 ng Al.

Interferences of acids in atomic absorption spectrophotometry

Abstract Hydrochloric, perchloric, nitric and phosphoric acids were examined to elucidate the mechanism of their interferences on the atomic absorption spectrophotometry of copper, iron and chromium. The interferences were complex in nature and varied for different elements and for different acids. The mechanism of the interferences is discussed.

Simultaneous determination of the major and minor elements in high-purity mullite by XRF analysis.

本蛍光X線分析法は,高純度ムライト微粉末中の主成分である二酸化ケイ素と酸化アルミニウム及び微量成分の同時迅速定量が可能であり,煩雑な操作を必要とせず約30分で分析が終了することから簡便性においても優れたものと考えられ,精度も満足すべき結果が得られた.本法は,高純度ムライト微粉末の品質管理に有効な分析方法と考えられる.

Elimination of Iron Interference on Atomic Absorption of Chromium with Air-Acetylene Flame

The interference of iron on the absorbance of chromium and its elimination in atomic absorption spectrometry was investigated by the use of air-acetylene flame.The depression of chromium absorption was observed in the spraying of chromium (III) and iron (III) mixture, while the enhancement was observed in the spraying of chromium (VI) and iron (III) mixture. However, the addition of hydroxylamine was effective to suppress iron interference on chromium absorption, presumably resulting from the reduction of iron In to iron (II). The elimination of iron interference was completed by the addition of hydroxylamine and o-phenanthroline. Possibly the organic ligands hinder the formation of mixed oxide in the condensed phase and release the chromium directly in the vapor state before a non-volatile oxide forms.This technique of interference elimination was applied to the determination of chromium in steels successfully.