Comparison of some analytical performance characteristics in inductively coupled plasma spectrometry of platinum group metals and gold

Talanta. 1999 Apr;48(4):859-66. doi: 10.1016/s0039-9140(98)00102-7.

Abstract

The limits of detection, precision and matrix effects in the inductively coupled plasma spectrometry of platinum group metals (PGMs) and gold were measured and evaluated for four ICP-AES and one ICP-MS instrument. The sample matrix was a cationic surfactant used for the PGMs and gold preconcentration on a modified silica gel (C18). A sorption of ion associates of PGMs and gold chlorocomplexes with the cation of onium salt N(1-carbaethoxypentadecyl)-trimethyl ammonium bromide was considered. The calibration curves, limits of detection and matrix effects were evaluated in the presence of 0.003 mol dm(-3) of onium salt (1.3 mg cm(-3)) and 0.1 mol dm(-3) HCl. The values of limits of detection (3 sigma(bl)) of PGMs for all axial ICP instruments were mostly below 10 ng cm(-3). Lateral observation on dual view ICP instrument yielded only 3 times higher detection limits in comparison to the axial mode of the same spectrometer and the detection limits for ICP-MS instrument were on the levels of units or tens of pg cm(-3). These limits of detection did not significantly differ from values obtained with pure solutions. Matrix effects in the presence of onium salt did not exceed 12% depression in the analytical signals. Besides the coefficients of correlation, the uncertainties on centroids of concentrations were calculated for calibration graphs obtained by linear regression.