Determination of Cu(II), Fe(III), Mn(II) and Zn(II) in various samples after preconcentration with Rhizopus oryzae loaded natural cellulose (almond bark)

Abstract

A procedure for the pre-concentration of Cu(II), Fe(III), Mn(II) and Zn(II) is described utilising a minicolumn of natural cellulose (almond bark) modified with fungus (Rhizopus oryzae) prior to their determination by high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS). The optimum pre-concentration conditions such as pH and flow rate for the analytes have been investigated. The analytes were quantitatively retained on the column between pH 6 and 8. Elution was made with 10 mL 1 M HCl solution. Under the optimum conditions, recoveries were found as 97 ± 3%, 96 ± 3%, 98 ± 3% and 94 ± 2% for Cu(II), Fe(III), Mn(II) and Zn(II), respectively, at 95% confidence level. The detection limits obtained from preconcentration of 50 mL of blank solutions (n = 11) were 1.6, 1.8, 2.8 and 1.2 µg L⁻¹ for Cu(II), Fe(III), Mn(II) and Zn(II), respectively. Relative standard deviations (RSD) of the recoveries for five replicate analyses were lower than 3%. The proposed method was validated by analysing certified reference materials (Peach Leaves SRM 1547 and Fish Tissue IAEA-407). Determination of the Cu(II), Fe(III), Mn(II) and Zn(II) in Kızılırmak River water, green beans, beans leave and tomato leaves and fish (Tinca tinca) tissue samples was performed by the proposed method.

Keywords:

• almond bark
• high-resolution continuum source flame atomic absorption spectrometry
• preconcentration
• Rhizopus oryzae
• trace metal

Acknowledgements

The authors are grateful to the Unit of the Scientific Research Projects of Nevşehir University for the financial support (Grant No 2011/3). The authors also thank to Assoc. Prof. Dr. H. Çiftçi for his kind assistance and advice.