Preconcentration and Determination of Cd, Zn and Ni by Flame Atomic Absorption Spectrophotometry by Using Microorganism Streptomyces Albus Immobilized on Sepiolite

Abstract

A method for the determination of Cd, Zn and Ni by flame atomic absorption spectrophotometry (FAAS) after preconcentrating on a column containing Streptomyces albus CIP 104432T immobilized on sepiolite has been developed. Optimum pH values, amount of adsorbent, elution solution and flow rate have been obtained for the elements studied. The effect of interfering ions on the recovery of the analytes has also been investigated. Recoveries of Cd, Zn and Ni by Streptomyces albus immobilized on sepiolite were 77.83± 0.30 , 93.80±0.47 and 98.73± 0.54 % at 95 % confidence level , respectively. The adsorption capacity of Streptomyces albus immobilized on sepiolite was found as 5.48 mg/g, 4.97 mg/g and 2.49 mg/g for Cd, Zn and Ni, respectively. The limit of detections (3s) were found to be 81 ng mL-1 for Ni, 53 ng mL-1 for Cd and 43 ng mL-1 for Zn. The proposed method was applied to the determination of trace metals in Simulated fresh water (SRM). Trace metals have been determined with relative error lower than 10 %. © 2013.