Application of silica gel 60 loaded with Aspergillus niger as a solid phase extractor for the separation/preconcentration of chromium(III), copper(II), zinc(II), and cadmium(II).

Sorption properties of silica gel 60 loaded with fungi cells characterized as Aspergillus niger were evaluated for trace enrichment of Cr(III), Cu(II), Zn(II), and Cd(II) from various water samples prior to the description of flame atomic absorption spectrometric analysis. The proposed SPE method is cheap, simple, highly sensitive, accurate, and selective for enrichment of analytes. The effect of experimental parameters, such as pH of sample solution, amount of solid phase, eluent type, and volume of sample solution on the recovery of the metal ions has been investigated. The effect of diverse ions was also investigated. The recoveries of Cr(III), Cu(II), Zn(II), and Cd(II) under the optimum experimental conditions were 98 +/- 2, 98 +/- 3, 99 +/- 2, 100 +/- 2%, respectively, at the 95% confidence level. The analytical detection limits were found to be 3.1, 1.6, 1.1, and 1.4 microg/L for Cr(III), Cu(II), Zn(II), and Cd(II), respectively. The proposed enrichment method was applied to the determination of analytes in Atatürk Dam, Egirdir Lake, and tap-water samples. The analytes were determined with a relative error lower than 8% in various water samples. The method has been validated by analyzing spiked water samples.