Preconcentration of trace elements from water samples on a minicolumn of yeast (Yamadazyma spartinae) immobilized TiO2 nanoparticles for determination by ICP-AES

A trace element preconcentration procedure is described utilizing a minicolumn of yeast (Yamadazyma spartinae) immobilized TiO2 nanoparticles for determination of Cr, Cu. Fe, Mn, Ni and Zn from water samples by inductively coupled plasma atomic emission spectrometry. The elements were quantitatively retained on the column between pH 6 and 8. Elution was made with 5% (v/v) HNO3 solution. Recoveries ranged from 98 +/- 2 (Cr) to 100 +/- 4 (Zn) for preconcentration of 50 mL multielement solution (50 mu g L-1). The column made up of 100 mg sorbent (yeast immobilized TiO2 NP) offers a capacity to preconcentrate up to 500 mL of sample solution to achieve an enrichment factor of 250 with 2 mL of 5% (v/v) HNO3 eluent. The detection limits obtained from preconcentration of 50 mL blank solutions (5%, v/v, HNO3. n = 11) were 0.17, 0.45, 0.25, 0.15, 0.33 and 0.10 mu g L-1 for Cr, Cu, Fe, Mn, Ni and Zn, respectively. Relative standard deviation (RSD) for five replicate analyses was better than 5%. The retention of the elements was not affected from up to 500 mu g L-1 Na+ and K+ (as chlorides), 100 mu g L-1 Ca2+ (as nitrate) and 50 mu g L-1 Mg2+ (as sulfate). The method was validated by analysis of freshwater standard reference material (SRM 1643e) and applied to the determination of the elements from tap water and lake water samples. (C) 2011 Elsevier B.V. All rights reserved.