Open AccessDevelopment of an Analytical Method for Trace Gold in Aqueous Solution Using Polyurethane Foam Sorbents: Kinetic and Thermodynamic Characteristic of Gold(III) Sorption
Author(s) -
Abdulaziz S. Bashammakh,
Saleh O. Bahaffi,
F. M. Alshareef,
M.S. El-Shahawi
Publication year - 2009
Publication title -
analytical sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.392
H-Index - 73
eISSN - 1348-2246
pISSN - 0910-6340
DOI - 10.2116/analsci.25.413
Subject(s) - chemistry , sorption , sorbent , aqueous solution , polyurethane , bromide , perchlorate , iodide , reaction rate constant , exothermic reaction , onium , adsorption , inorganic chemistry , ion , analytical chemistry (journal) , chromatography , kinetics , organic chemistry , physics , quantum mechanics
The kinetic parameters of gold(III) sorption by unloaded polyurethane foams (PUFs) and PUFs impregnated with some onium cations e.g. tetramethylammonium perchlorate (TMA(+)ClO(4)(-)), tetrabutylammonium iodide (TBA(+)I(-)), and tetraheptylammonium bromide (THA(+)Br(-)), have been determined. The retention steps were found to be fast, reached equilibrium in a few minutes and followed a first-order rate equation with an overall rate constant, k, of 0.0076 and 0.007 min(-1), respectively. The thermodynamic characteristics of gold(III) retention by the unloaded PUFs and THA(+)Br(-) immobilized PUFs have been critically studied. The negative values of DeltaH and DeltaS are interpreted as the exothermic and spontaneous reaction of gold(III) sorption onto unloaded PUFs and foams impregnated with THA(+)Br(-). The cellular structure of the PUFs sorbent offer unique advantages over conventional bulk-type sorbents in the rapid, versatile effective separation and/or preconcentration of gold ions.