Substoichiometric radioisotope dilution analysis for traces of mercury by solvent extraction with silver diethyldithiocarbamate

Determination of extraction constants for metal diethyldithiocarbamates and chloride-mixed metal diethyldithiocarbamates by substoichiometric extraction

“…Extraction constants of various metal diethyldithiocarbamates differ over several decade orders of magnitude (2). The values of the extraction constants are of great importance in predicting the feasibility of separating selectively a single metal or a group of metals by choosing a proper metal diethyldithiocarbamate as extraction reagent (3)(4)(5)(6)(7)(8). So far very little information on the extraction constants has been obtained, although the qualitative extraction order for a variety of metals under specified conditions has been investigated by several authors (6,(9)(10)(11)(12)(13).…”

“…In 1968, Ruzicka and Stary introduced the substoichiometric extraction method (16). Since then, the method has been extensively used in analytical work (4,7,9,17,18). The characteristic feature of the method is that the quantity of extractant is adjusted appropriately so as to extract only partial amounts of the metal or metals of interest.…”

Lead, cadmium, and zinc bis(diethyldithiocarbamate) and diethyldithiocarbamic acid as reagents for liquid-liquid extraction

“…Substitution of these reagents by metal diethyldithiocarbamates (dissolved in an organic diluent) results in an improved stability in contact with acid aqueous solutions and in an increased specificity of the extraction. Examples for the application of metal dithiocarbamates as reagents can be found in many publications (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11).…”

“…Joris et al (17,18) showed that aqueous solutions of HDDC decompose according to MHDDC] (7) where k (the true rate constant) is 0.1 s_1. The apparent rate constant k' is in general pH-dependent, but in the region used in our work (pH 0-3) can be considered constant and equal to k.…”