CLOUD POINT EXTRACTION FOR PRE-CONCENTRATION AND DETERMINATION OF PALLADIUM IN WATER AND FOOD SAMPLES BY VISUAL AND FLAME ATOMIC ABSORPTION SPECTROMETRYY

Abstract

The cloud point extraction (CPE) method was successfully employed for the separation and pre-concentration of trace amounts of palladium prior to its determination either by flame atomic absorption spectrometry (FAAS) or using visual spectrophotometry. Palladium(II) reacts with 2-Hydroxyimino-3-(2-hydrazonopyridyl)-butane (HHB) as chelating agent in the presence of p -octylpolyethyleneglycolphenylether (Triton X-100) as a nonionic surfactant giving a purple to pink surfactant rich phase chelate which could be used for CPE. The effects of experimental conditions such as pH, chelating agent and surfactant concentrations, equilibration temperature and time on CPE were studied. The performance characteristics of the method such as linearity, detection limit, pre-concentration and improvement factors were evaluated. Linearity was obeyed in the range of 0.5−15 and 0.4-18.0 ng mL −1 of Pd (II) with a detection limit of 0.08 and 0.035 ng mL −1 using FAAS and visual spectrometry, respectively. Validation of the method revealed good performance characteristics including good selectivity for Pd 2+ over a wide variety of other diverse cations and anions, high reproducibility, low detection limit, acceptable accuracy and precision. The proposed method was successfully applied for the assessment of palladium (II) traces in water and food samples with satisfactory results.