MULTIVARIATE OPTIMISATION OF ICP-OES INSTRUMENTAL PARAMETERS FOR SELENIUM MEASUREMENT IN ANTIMONY CONCENTRATE

Abstract

Inductively coupled plasma-optical emission spectrometry (ICP-OES) is a powerful analytical tool for
the determination of metals. It is simple, fast and inexpensive due to its high sensitivity. It is widely used
to determine the selenium content in different samples of concentrates. In this study, experiments were
designed using multivariate optimisation to establish the best operating conditions for ICP-OES to
measure selenium in antimony concentrates. Three variables were studied (radio frequency power,
nebuliser gas flow and aspiration rate), and the interactions between those variables were investigated
using a response surface methodologies design to establish the best analysis parameters. Analysis of
variance (ANOVA) at a p-value significance level of 0.05 was used to assess the significance of the
factors on selenium analytical line emission intensity. The main effects of radio frequency power,
nebuliser gas flow and aspiration rate and the interaction effect of carrier nebuliser gas flow and
aspiration rate , were found to be statistically significant. The optimum values determined for radio
frequency power, nebuliser gas flow and aspiration rate were 1300 W, 0.7 L min−1 and 1.2 mL min−1
,
respectively.