Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10559687 | Talanta | 2011 | 8 Pages |
Abstract
The present paper describes the synthesis of a new chemically modified cellulose microfiber through oxidation with sodium periodate and functionalization with N,Nâ²-bis (2-aminoethyl)-1,2-ethanediamine for the fast and selective preconcentration of Cd(II) ions in flow system analysis. The new sorbentsorbent was characterized by FTIR, SEM, and surface area values. The uptake behavior of Cd(II) ions onto this sorbent was evaluated from kinetic data, pseudo-first-order and pseudo-second-order models, as well as from Langmuir, Freundlich and Langmuir-Freundlich adsorption isotherms. The maximum sorption capacity of 4.59 mg gâ1 was estimated by the Langmuir-Freundlich model with fast kinetics for the sorption of Cd(II) described by the pseudo-second-order kinetic model. After characterization, the sorbent was packed in a mini-column, and a fast flow injection preconcentration system for Cd(II) determination by FAAS was developed. The best Cd(II) preconcentration condition, obtained by means of factorial design and response surface methodology, was achieved at pH 9.36 and a flow rate of 10 mL minâ1 followed by elution with 1.0 mol Lâ1 nitric acid. By using 78 s preconcentration time, fast and highly sensitive determination of Cd(II) ions could be achieved with a limit of quantification of 0.20 μg Lâ1, preconcentration factor of 26, consumption index of 0.5 mL, concentration efficiency of 20 minâ1, and sample throughput of 39 hâ1. The repeatability for 10 replicate determinations was found to be 7.8 and 2.5% for Cd(II) ion concentrations of 5.0 and 100.0 μg Lâ1, respectively. The new sorbent efficiency for the interference-free preconcentration of Cd(II) ions was assessed by analysis of tap, mineral and lake waters, as well as synthetic seawater and normal saline waters. Furthermore, complex samples, such as biological samples, could be analysed by the proposed method in accordance with the accuracy attested by analysis of certified reference materials, TORT-2 (lobster hepatopancreas), and DOLT-4 (dogfish liver).
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Fernanda Midori de Oliveira, Bruna Fabrin Somera, Marcela Zanetti Corazza, Maria Josefa Santos Yabe, Mariana Gava Segatelli, Emerson Schwingel Ribeiro, Ãder Cláudio Lima, Silvio LuÃs Pereira Dias, César Ricardo Teixeira Tarley,