X-ray fluorescence analysis of trace metal ions following a preconcentration of metal-diethyldithiocarbamate complexes by homogeneous liquid-liquid extraction

A homogeneous liquid-liquid extraction method for 36 metal ions with diethy ldithiocarbamate was studied. As a result, 11 metal ions were extracted as metal-chelates. Under the experimental conditions, the maximum concentratio n factor was 500 (i.e., 0.1 mL of sedimented liquid phase was produced from 50 mL of aqueous phase). Moreover, the proposed method was utilized as a p reconcentration method for X-ray fluorescence analysis of these metals. The recovery of each metal was ca. 97-100%. All calibration curves were linear over the range of 5.0 x 10(-7) mol L-1 to 1.0 x 10(5) mol L-1. The detecti on limits were at the 10(-8) mol L-1 levels and the relative standard devia tions were below 5% (5 determinations). When the proposed method was used f or the determination of contaminants in a synthetic sample (Al-based alloy model) and of components in an Au-Pd alloy, the results were satisfactory.