TITLE:
Determination of Cobalt in Food, Environmental and Water Samples with Preconcentration by Dispersive Liquid-Liquid Microextraction
AUTHORS:
Catalina Bosch Ojeda, Fuensanta Sánchez Rojas, José Manuel Cano Pavón
KEYWORDS:
Cobalt; Dispersive Liquid-Liquid Microextraction; Flame Atomic Absorption Spectrometry; Water; Environmental and Food Samples
JOURNAL NAME:
American Journal of Analytical Chemistry,
Vol.3 No.2,
February
22,
2012
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.