Determination of Cobalt in Food, Environmental and Water Samples with Preconcentration by Dispersive Liquid-Liquid Microextraction

Catalina Bosch Ojeda, Fuensanta Sánchez Rojas, José Manuel Cano Pavón

Department of Analytical Chemistry, Faculty of Sciences, University of Málaga, Málaga, Spain.

DOI: 10.4236/ajac.2012.32018                

Abstract

A new method for the determination of cobalt was developed by dispersive liquid-liquid microextraction preconcentra-tion and flame atomic absorption spectrometry. In the proposed approach, 1,5-bis(di-2-pyridyl) methylene thiocarbohydrazide (DPTH) was used as a chelating agent, and chloroform and ethanol were selected as extraction and dispersive solvents. Some factors influencing the extraction efficiency of cobalt and its subsequent determination, including extraction and dispersive solvent type and volume, pH of sample solution, concentration of the chelating agent, and extraction time, were studied and optimized. Under the optimum conditions, a preconcentration factor of 8 was reached. The detection limit for cobalt was 12.4 ng?mL–1, and the relative standard deviation (RSD) was 3.42% (n = 7, c = 100 ng?mL–1). The method was successfully applied to the determination of cobalt in food, environmental and water samples.

Keywords

Cobalt; Dispersive Liquid-Liquid Microextraction; Flame Atomic Absorption Spectrometry; Water; Environmental and Food Samples

Conflicts of Interest

The authors declare no conflicts of interest.

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