Online Preconcentration Using Surfactant Coated Alumina Modified with 1,5-Diphenylthiocarbazone and Determination of Cadmium in Environmental Samples by Flame Atomic Absorption Spectrometry

A rapid and sensitive method for the determination of trace levels of cadmium in cigarettes, soil, and blood samples by flame atomic absorption spectrometry (FAAS) has been developed. It is based on the online sorption of Cd(II) ions on a minicolumn packed by sodium dodecyl sulfate–coated alumina modified with dithizone. The optimum experimental parameters for the adsorption and desorption of cadmium were investigated. The recovery obtained was found to be 96% with preconcentration factor of 150. The calibration curve was linear between 50–600 µg/L Cd with a detection limit of 3 µg/L, sample frequency of 30 h^?1 and reuse of column for 10 times without loss of sensitivity. The accuracy of the method was confirmed by applying the standard addition method and quantitative recoveries (95–99%) were obtained.