TY - JOUR

T1 - Determination of minor alloyed elements in steel samples in radio-frequency glow discharge plasma optical emission spectrometry associated with pulsed bias-current modulation technique

AU - Urushibata, Satomi

AU - Wagatsuma, Kazuaki

PY - 2012

Y1 - 2012

N2 - An advanced detection method based on a modulation technique is described in radio-frequency-powered glow discharge plasma optical emission spectrometry (r.f. GD-OES). A frequency-sensitive separation using a fast Fourier transform (FFT) analyser, where a pulsated bias-current was introduced into an r.f. GD plasma, was available for improving the limit of determination for the atomic emission analysis. The FFT analyser has an ability to disperse signal components by frequency, and it is thus employed to select the component of a particular frequency. A dc bias current introduced into the GD plasma can enhance the emission intensities of analyte species greatly, and furthermore, it can be easily pulsated to modulate the emission intensities from the plasma. The modulated emission signal was selectively detected with the FFT analyser, with removing any noise components from the overall signal. The duty ratio of the pulsed bias current largely affected the amplitude of the FFT frequency components, because the pulse waveform comprised sine-function components having frequencies integral-times as much as the fundamental frequency, whose contribution coefficients depended on the duty ratio. This detection method was applied to the determination of vanadium and molybdenum in low-alloyed steel samples. The detection limits were obtained to be 6.2 × 10-3 mass% V and 2.0 × 10-3 mass% Mo in low-alloyed steel samples.

AB - An advanced detection method based on a modulation technique is described in radio-frequency-powered glow discharge plasma optical emission spectrometry (r.f. GD-OES). A frequency-sensitive separation using a fast Fourier transform (FFT) analyser, where a pulsated bias-current was introduced into an r.f. GD plasma, was available for improving the limit of determination for the atomic emission analysis. The FFT analyser has an ability to disperse signal components by frequency, and it is thus employed to select the component of a particular frequency. A dc bias current introduced into the GD plasma can enhance the emission intensities of analyte species greatly, and furthermore, it can be easily pulsated to modulate the emission intensities from the plasma. The modulated emission signal was selectively detected with the FFT analyser, with removing any noise components from the overall signal. The duty ratio of the pulsed bias current largely affected the amplitude of the FFT frequency components, because the pulse waveform comprised sine-function components having frequencies integral-times as much as the fundamental frequency, whose contribution coefficients depended on the duty ratio. This detection method was applied to the determination of vanadium and molybdenum in low-alloyed steel samples. The detection limits were obtained to be 6.2 × 10-3 mass% V and 2.0 × 10-3 mass% Mo in low-alloyed steel samples.

KW - Bias current

KW - Fast Fourier transform

KW - Modulation detection

KW - Optical emission spectrometry

KW - Radio-frequency glow discharge plasma

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U2 - 10.2355/isijinternational.52.1616

DO - 10.2355/isijinternational.52.1616

M3 - Article

AN - SCOPUS:84866405287

SN - 0915-1559

VL - 52

SP - 1616

EP - 1621

JO - Transactions of the Iron and Steel Institute of Japan

JF - Transactions of the Iron and Steel Institute of Japan

IS - 9

ER -