Optimization of Air-assisted Liquid–liquid Microextraction by Box–behnken Design for Spectrophotometric Determination of Palladium in Water Samples

Resumo

In this research, a fast, simple and highly efficient sample pretreatment technique based on air-assisted liquid–liquid microextraction (AALLME) followed by UV−Vis spectrophotometric detection has been applied for the preconcentration and determination of palladium in water samples. 1-(2-Pyridylazo)-2-naphthol (PAN) and chloroform were used as a chelating agent and extraction solvent, respectively. Parameters affecting AALLME, including pH of sample solution, concentration of PAN, volume of extraction solvent and number of extraction cycles were studied and optimized using Box–Behnken design. Under the optimum conditions, the calibration curve was linear in the concentration range of 5–700 ng/mL with the correlation coefficient (r²) of 0.996. Detection limit, enrichment factor, intra- and inter-day precision were 0.7 ng/mL, 193, 1.3 and 1.8%, respectively. Finally, the developed method was successfully applied for the determination of trace amounts of palladium in environmental water samples.