Cloud Point Extraction for the Preconcentration of Silver and Palladium in Real Samples and Determination by Atomic Absorption Spectrometry

A cloud point extraction procedure is presented for the preconcentration and simultaneous determination of Ag+ and Pd2+ in various samples. After complexation with 2((2-((1H-benzo[d]imidazole-2-yl)methoxy)phenoxy)methyl)-1H-benzo[d]imidazol (BIMPI), which was used as a new chelating agent, analyte ions were quantitatively extracted to a phase rich in Triton X-114 following centrifugation, and determination was carried out by flame atomic absorption spectrometry (FAAS). Under the optimum experimental conditions (i.e., pH = 7.0, 15.0 . 10(-5) mol/L BIMPI and 0.036% (w/v) Triton X-114), calibration graphs were linear in the range of 28.0-430.0 mu g/L and 57.0-720.0 mu g/L with detection limits of 10.0 and 25.0 mu g/L for Ag+ and Pd2+, respectively. The enrichment factors were 35.0 and 28.0 for Ag+ and Pd2+, respectively. The method has been successfully applied to evaluate these metals in some real samples, including waste water, soil and hydrogenation catalyst samples.