Chemical modification of alumina surface by immobilization of 1-((5-nitrofuran-2-yl)methylene)thiosemicarbazide for extractive concentration of silver ions

Abstract

A column, solid phase extraction (SPE), preconcentration method was developed for determination of silver by using alumina coated with 1-((5-nitrofuran-2-yl)methylene)thiosemicarbazide and determination by flame atomic absorption spectrometry. The separation/preconcentration conditions for the quantitative recovery were investigated. At pH 2, the maximum sorption capacity of Ag⁺ was 7.5 mg g⁻¹. The linearity was maintained in the concentration range of 0.02–11.0 µg mL⁻¹ in the final solution or 0.14–1.10 × 10⁴ng mL⁻¹ in the original solution for silver. The preconcentration factor of 140 and relative standard deviation of ±1.4% was obtained, under optimum conditions. The limit of detection (LOD) was calculated as 0.112 ng mL⁻¹, based on 3σ_bl/m (n = 8) in the original solutions. The proposed method was successfully applied to the determination trace amounts of silver in the environmental samples such as tea, rice and wheat flour, mint, and real water samples.

Keywords:

• alumina
• thiosemicarbazide derivative
• silver
• preconcentration
• environmental sample