DETERMINATION OF IRON AND NICKEL BY FLAME ATOMIC-ABSORPTION SPECTROPHOTOMETRY AFTER PRECONCENTRATION ON SACCHAROMYCES-CEREVISIAE IMMOBILIZED SEPIOLITE

Iron and nickel have been preconcentrated on Saccharomyces cerevisiae immobilized sepiolite and determined by flame atomic absorption spectr ophotometry (FAAS). Preconcentration studies were conducted by the col umn method. Effect of pH, amount of adsorbent, elution solution, flow rate and interfering ions on the recovery of the analytes have been in vestigated. Recoveries of Fe and Ni were 95 +/- 1 and 99.5 +/- 0.1%, r espectively, at 95% confidence level. The breakthrough capacities of a nalytes were also investigated and found to be 0.042 mmol g(-1) for Fe and 0.055 mmol g(-1) for Ni. The proposed method was applied to the d etermination of iron and nickel in brass (NBS SRM 37e). The detection limit of iron and nickel were found as 0.065 and 0.087 mu g ml(-1), re spectively. The direct determination of trace metals by flame atomic a bsorption spectrometry (FAAS) is limited and difficult because of low concentration and/or matrix interferences. The proposed method is exce llent for the determination of trace metal in matrixes, such as metal alloys. (C) 1998 Elsevier Science B.V. All rights reserved.