Determination of Metals in Solid Samples by Complexation: Supercritical FluidExtraction and Gas Chromatography. Atomic Emission Detection

摘要

Complexation followed by Supercritical fluid extraction (SFE) has beeninvestigated for the extraction of Cu(2+), Co(2+), and Zn(2+) ions from solid samples. Lithium bis(trifluoroethyl)dithiocarbamate (FDDC) was used as the complexing agent in the study. The metal-FDDC complexes in the SFE extracts were determined by gas chromatography (GC) with atomic emission detection. The recoveries of Cu(2+), Co(2+), Cd(2+), and Zn(2+) ions from filter paper, sand, and silica gel ranged from 70 to 100 percent. Relatively high concentrations of complexed Cu, Co, Cd, and Zn found in system blanks obtained with a stainless steel SFE system prompted the authors to modify the apparatus by using nonmetalic polyetheretherketone (PEEK) components.