Simultaneous Spectrographic Determination of Nickel, Manganese and Chromium by Plasma Jet Arc Technique

A Shimadzu-type plasma jet arc unit equipped with a ceramic nozzle was employed in this study.Various parameters of the plasma jet arc were quantitatively studied, their interrelations were clarified, and criteria for the optimum conditions were establshed.Distance of the analytical gap, position of the cathode, flow rate of helium, plasma flow, arc resistance operating current and voltage, sample size, spatial distribution of the ratio of line intensity to back-ground in the analytical gap, and influence of extraneous elements on the spectral intensity of the aimed elements were investigated.As a result, the simultaneous determination of consituent elements in various metals and alloys has been proved to be possible by the use of a plasma jet arc without any matrix effect.Single, widely applicable calibration curves for nickel, manganese and chromium were obtained by the use of acidic solutions of the standard samples.The plasma jet arc unit described here can be utilitized as a practical device durable for long runs.