Separation and preconcentration followed by ICP-OES and ICP-MS determination of precious metals using silica gel chemically modified with dithiocarbamate groups

ABSTRACT Silica gel chemically modified with dithiocarbamate groups (DTCS) was used for separation and preconcentration of precious metals and their subsequent determination in geological samples and their processing products by inductively coupled plasma optical emission spectrometry and inductively coupled plasma mass spectrometry. DTCS was characterized by TGA/DSC, FT-IR, and CHNS-analysis. DTCS quantitatively extracted Au3+, Pd2+, Pt2+, Pt4+ at 20°C from 0.5 to 4.0 M HCl media and Rh3+, Ir4+, Ru4+, and Os4+ at 95°C in the presence of 0.025 M SnCl2. Two-column procedure was proposed to separate precious metals from matrix components and to separate kinetically inert precious metals from kinetically labile ones.