Precise determination o manganese in steel by dc glow discharge optical emission spectrometry associated with voltage modulation technique

摘要

A voltage modulation technique was applied for the precise and accurate determination of manganese in steels in dc glow discharge optical emission spectrometry.Emission signals from the glow discharge plasma are modulated by a cyclic variation of the discharge voltage so that only the desired signals can be detected at very low noise levels by using a lock-in amplifier.Mn determination in low-alloyed steels was performed to estimate the repeatability of the anaytical result.For each measurement,the relative standard deviation (R.S.D.)of the intensities of the Mn I 403.08-nm line was ca 0.1% when a steel sample containing 0.329 mass% Mn was employed.Averaging all analytical values,Which are obtained in various discharge conditions,yields statistical information on the precision and accuracy for the analytical values obtained.the relative error from the recommended value is calculated to be 0.5%.TheR.S.D.over the analytical values is 1.5%,representing the overall analytical performance of thsi technique.