Correction factor based on the ratio of the magnesium atom to ion background signals used for evaluating robustness in inductively coupled plasma optical emission spectrometry

The ratio of the magnesium ion to atom signals with wavelengths of 280.270 and 285.213 nm, respectively, is frequently employed to estimate plasma robustness in inductively coupled plasma optical emission spectrometry. To guarantee a rigorous and accurate calculation of this indicator of the plasma condition, a correction for the difference in the response of the instrument at the two wavelengths of magnesium has been frequently applied. However, the literature reviewed shows inconsistencies in the values of the correction factor used. Also it is notable the lack of information concerning the procedures to calculate such correction factor. In this paper, we propose a simple method for the best estimate of the correction factor from an appropriate measurement of the magnesium atomic and ion background signals, when a blank solution, contaminated by magnesium, is nebulized. We proved that a bad selection of the wavelengths used for background signal estimation can underestimate the correction factor up to a 56%.