Preconcentrations of Ni(II) and Co(II) by using immobilized thermophilic Geobacillus stearothermophilus SO-20 before ICP-OES determinations.

This study deals with the preconcentrations of Ni(II) and Co(II) ions in real samples using the solid phase extraction method (SPE) before their determinations by inductively coupled plasma optical emission spectrometry (ICP-OES). Thermophilic bacterium Geobacillus stearothermophilus SO-20 (Accession number: KJ095002), loaded with Amberlite XAD-4, was utilized as a novel biosorbent. Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscope (SEM) were employed for the investigation of the bacterial surface before and after Ni(II) and Co(II) biosorption. The experimental parameters were examined to find the best conditions. The retained Ni(II) and Co(II) ions on the biosorbent were eluted by using 5.0 ml of 1.0 mol l-1 HCI as the best eluent. The sorption capacities were found to be 16.8 mg g-1 for Ni(II) and 21.6 mg g-1 for Co(II). It was also successfully used for the quantification of Ni(II) and Co(II) in a river water sample, some vegetables and soil.