Syn-ichi Itoh

Electrothermal atomic-emission spectrometric determination of lithium with a metal-tube atomizer and a matrix modifier

Electrothermal atomic-emission spectrometric determination of lithium with use of a tungsten tube has been investigated. Lanthanum nitrate is used as a matrix modifier to eliminate the interference of Al, Ca, Cu, Fe, K, Mg, Na, Pb and Zn. Lithium in biological samples has been determined by the method. The recovery of lithium in the samples was > 91%.

Determination of aluminium in biological materials by electrothermal atomic absorption spectrometry with a tungsten tube atomizer

Abstract Electrothermal atomic absorption spectrometry (ETA-AAS) of aluminum with a tungsten tube atomizer was investigated. By the addition of hydrogen to the argon purge, a sensitive ETA-AAS method was developed. The optimum gas flow-rates were argon 300 ml min −1 and hydrogen 200 ml min −1 . The absolute characteristic mass (the mass of element giving 0.0044 absorbance) of aluminium by the atomizer was 0.98 pg and the detection limit was 52 pg ml −1 . These values were more than ten times better than those obtained using a graphite atomizer, inductively coupled plasma (ICP), flame AAS, neutron activation analysis, x-ray fluorescence spectrometry and ICP mass spectrometry. The interferences caused by large amounts of interferents were evaluated. For severe interferences, the standard additions method was applied to the determination. The analytical results were in good agreement with the certified values.

ELECTROTHERMAL ATOMIZATION ATOMIC ABSORPTION SPECTROMETRY OF CADMIUM WITH A PLATINUM TUBE ATOMIZER

The determination of cadmium by electrothermal atomization atomic absorption spectrometry with a platinum tube atomizer in the presence of air has been investigated. The detection limit of cadmium was 0.09 pg (9 pg/ml for a 10-mul volume). The relative standard deviation of the measurement was 2.9%. For 2.5 pg of cadmium, Cu, Pb, Zn, Al, Ca, Fe, K, Mg and Na (10(4)-10(5)-fold) did not interfere with the absorption signal. The method has been applied to the determination of cadmium in some biological materials. The average analytical value found for the standards lay within the limits of the certified values. The remarkable merits of the platinum atomizer are its stability in air and long life-time (able to withstand more than 1000 heating cycles in air).

Determination of Cobalt with a Tungsten Tube Atomizer by Electrothermal Atomic Absorption Spectrometry and its use for the Analysis of Biological Materials

Abstract The determination of cobalt by electrothermal atomic absorption spectrometry with a tungsten tube atomizer has been investigated. The absolute characteristic mass (the mass of element giving 0.0044 abs.) of cobalt by the atomizer was 5.8 pg and the detection limit was 0.65 ng/ml (3S/N). The interferences caused by large amounts of interferents like Al, Ca, Cu, Fe, K, Mg, Na, Pb and Zn were evaluated and most of these elements were found to interfere with the cobalt signal. Ammonium thiocyanate as a chemical modifier was found to be efficient to eliminate the severest interferences. The accuracies of the recommended method were found to be almost satisfactory for the determination of cobalt in biological materials, as shown by a comparison with the reported values of NIST materials at the 0.02–0.4 μg/g level.

Determination of rhodium in waters by Mg-W cell-electrodeposition and electrothermal atomic absorption spectrometry.

A new concentration method of rhodium using Mg-W cell-electrodeposition has been developed. The method was combined with electrothermal atomic absorption spectrometry (ETAAS) with a tungsten tube atomizer. The optimal immersing time was 120 s. The most suitable pH for rhodium electrodeposition was 1.0. Under optimal conditions, the detection limit of rhodium by the ETAAS with the preconcentration was 13 ng ml(-1) (3S/N). The severe interferences on the AAS signal of rhodium by large amounts of Ca, Cu, Fe, K, Na, Pb and Zn were eliminated by the Mg-W cell-electrodeposition method. The method was applied to the determination of rhodium in river and sea water. The recovery of rhodium spiked environmental samples was in the range of 95.6-109%. The present Mg-W cell-electrodeposition method can be utilized in in-situ sampling of trace elements in environmental samples (water). Furthermore, after sampling, it is easy to carry and store the W-sheet without contamination for a long time.

Electrothermal Atomization Atomic Absorption Spectrometry with Platinum Tube Atomizer in Air

Abstract An electrothermal atomization method of atomic absorption spectrometry using a platinum tube atomizer in air is described. The atomizer consists of 0.025 mm-walled platinum tube and two supports. The remarkable merit of the platinum atomizer is the stability in air, when heated. This paper describes the improved performance for volatile elements like alkalimetals. Detection limits and characteristic mass are calculated for 7 elements and compared with literature values. The platinum atomizer can be used with a simple, effective and relatively low-cost atomic absorption spectrometer for routine in situ analysis.

MG-W Cell—Electrothermal Atomic Absorption Spectrometry—Determination of Gold in Environmental Samples

An electrodeposition method of trace elements using a Mg-W cell is reported. This method does not need a power supply (electric source) like a potentiostat or a battery. Some elements electrodeposited on a W sheet were detected by electrothermal atomic absorption spectrometry (ETAAS) with a tungsten atomizer. The detection limits of Au, Sb, Te and Tl by Mg-W cell-ETAAS were 55, 48, 47 and 880 pg/mL, respectively. The severe interferences of Al, Ca, Cu, Fe, K, Na, Pb and Zn on Au-AAsignal, which were observed in AAS, were eliminated by use of the Mg-W cell. The Mg-W cell electrodeposition method was applied to the determination of Au in sea and surface water samples. The recovery of gold in spiked environmental samples was in the range of 91 to 104%.