Multielemental inductively coupled plasma optical emission spectrometry analysis of nickeliferous minerals

• ICP-OES method has been optimized for analysis of nickeliferous minerals.
• Influence of operating parameters on SBR and matrix effect was studied.
• Robust operating plasma conditions and matrix matching calibration curves were used.
• Precision of analysis was around 10% for most elements.

An inductively coupled plasma optical emission spectrometry method for the quantitative simultaneous determination of Al, Ca, Co, Cu, Cr, Fe, K, Mg, Mn, Na, Ni, P and Zn in Cuban laterite and serpentine minerals has been developed. Additionally, V and Ti can be quantitatively determined in laterite mineral; Li, Sr, and Zr can be detected in both mineral types and Pb can be detected just in laterite mineral. The microwave-assisted total acid digestion of samples was achieved with HCl+HNO3+HF and HNO3+HClO4+HF acid mixtures for laterite and serpentine samples, respectively. In non-robust plasma operating conditions, the matrix effect characteristics of the laterite sample were dictated by the principal component Fe; while the character of the Mg principal component matrix effect was some how modified by the concomitants Fe and Ni in serpentine sample. The selection of robust conditions decreased the matrix effect. Additionally, the simulation of the matrix samples by introducing the principal component Fe or Mg, correspondingly, in calibration dissolutions was needed to overcome completely the matrix effect over the analysis accuracy. Precision of analysis was very near or lower than 10% for most elements, except Sr (15%) in L-1; and K (15%) and Li (15%) in SNi sample. Accuracy of analysis was around or lowers than 10% for most elements, except K (15%), Na (19%), P (19%) and V (19%) in L-1 sample; and Ca (14%) and P (20%) in SNi sample.

Variation of the matrix effect with the total excitation energy of line in non-robust conditions for: (a) laterite simulated matrix; (b) serpentine simulated matrix; (c) individual Fe matrices; (d) individual Mg matrix.Figure optionsDownload as PowerPoint slide