Flotation/magnetic stirring-assisted liquid-liquid microextraction combined with flame atomic absorption spectrometry for the preconcentration and determination of cadmium (II) after optimization using experimental design

Arapid, highly sensitive and efficient flotation/magnetic stirring-assisted liquid-liquid microextraction combined with flame atomic absorption spectrometry has been proposed for the preconcentration and quantitative analysis of trace amounts of cadmium (II) in the presence of sodium diethyldithiocarbamateas complexingagent. Parameters including sample pH, concentration of the complexingagent, volume of extraction solvent, extraction time and aeration time were screened by a Plackett–Burman design and optimal conditions were obtained using a Box-Behnken design. At optimum conditions, the limit of detection and relative standard deviation (n=7, C=20 µg L−1) were 0.16 µg L-1 and 1.39%, respectively. Furthermore, a linear dynamic range of 0.5-80 µg L−1and enrichment factor of 152 were obtained. The accuracy of the method was evaluatedusing the analysis of certified reference material. Finally, the proposed techniquewas successfullyusedfor the determination of trace amounts of cadmium (II) in water and cereal samples.