Flow injection on-line minicolumn preconcentration and determination of trace copper ions using an alumina/titanium oxide grafted silica matrix and FAAS

Abstract

We describe the analytical performance of a hybrid material composed of SiO 2 , Al 2 O 3 and TiO 2 . It was prepared by a sol-gel process and can act as an adsorbent in the continuous-flow enrichment of copper. A minicolumn was packed with the material, copper ions are adsorbed at pH 9.13, then eluted with 1.0 mol L −1 nitric acid, and determined by FAAS. The material was characterized by infrared spectroscopy, scanning electron and energy dispersive spectroscopy, energy dispersive X-ray fluorescence analysis, powder Xray diffraction, and specific surface area analysis. No significant interference was observed for most ions in up to copper/ interferent ratios of 1:100 and of 1:500 in case of Ca(II), Ba (II), and Mg(II). The breakthrough capacity is 1.4 mg g −1 under dynamic conditions. The limits of detection and of quantification are 0.50 and 1.4 μg L −1 , respectively, and the calibration plot is linear in the range from 5.0 to 245.0 μg L −1 (r00.999). The relative standard deviation is 3.20 (for n07 and at a Cu(II) concentration of 10 μg L −1 ). The method was applied to the determination of trace copper ions in water, vegetable and alcohol fuel samples.

Ultrasensitive colorimetric detection of Cu2+ ion based on catalytic oxidation of l-cysteine

“…As seen from Table S1, methods such as ICP-MS (Wu and Boyle, 1997;Dai et al, 2012) and AAS (Chan and Huang, 2000;Lima et al, 2012) can detect Cu 2 þ ion with high sensitivity and selectivity, but they require large-scale instruments and highly trained operators restricting the practical on-site detection. The fluorometry methods also own good selectivity, but they are often troubled with complicated synthesis (Chan et al, 2010;Yu et al, 2011;Yuan et al, 2013;Zhang et al, 2013).…”

“…Methods such as ICP-MS (Wu and Boyle, 1997;Dai et al, 2012) and AAS (Chan and Huang, 2000;Lima et al, 2012) can detect Cu 2 þ ion with high sensitivity and selectivity but with requirements of large instruments. Compared with electrochemical techniques (Liu et al, 1999;Salaun and van den Berg, 2006;Lin et al, 2012) and fluorescence methods (Chan et al, 2010;Yu et al, 2011;Yuan et al, 2013;Zhang et al, 2013) are much simpler with detection by naked eyes and UV-vis spectroscopy (Lou et al, 2011;Liu et al, 2013;Shen et al, 2013;Wang et al, 2014).…”

Synthesis of Chelating Agent Free-Solid Phase Extractor (CAF-SPE) Based on New SiO2/Al2O3/SnO2 Ternary Oxide and Application for Online Preconcentration of Pb2+ Coupled with FAAS

“…39 The adsorption isotherm showed no hysteresis (Figure 4a) and its concave format indicates that the amount adsorbed approaches a limiting value. This limiting uptake is governed by the accessible pore volume rather than by the internal surface area.…”

“…One should note that, the presence of roughness on the surface of material can facilitate mass transfer and provides an increase in the surface area. 39,40 In order to obtain a rough estimation of mass percentages of the components and the dispersion of aluminium and tin in the surface of material, EDS spectrum (data not shown) and elemental mapping were recorded, respectively.…”

“…One should note that, the presence of roughness on the surface of material can facilitate mass transfer and provides an increase in the surface area. 39,40 In order to obtain a rough estimation of mass percentages of the components and the dispersion of aluminium and tin in the surface of material, EDS spectrum (data not shown) and elemental mapping were recorded, respectively.From EDS spectrum of SiAlSn (data not shown), it was found percentages of O (70.00 wt.%), Si (25.46 wt.%), Al (1.71 wt.%) and Sn (2.82 wt.%); obtaining an atomic molar ratio of Si/Al = 14.3 and Si/Sn = 38.2. From the EDS images (Figure 2), no phase segregation or oxide particle islands were observed with the studied magnification, showing highly dispersed metal oxides due to strong covalent bonding interaction with the siloxane groups in the silica matrix.…”