Studies about the adsorption of di-2-pyridyl ketone salicyloylhydrazone (DPKSH) on Amberlite XAD-2 and XAD-7 resins. Extraction of ion Cu(II) using the solid phase XAD-7 modified with DPKSH / Estudos de adsorção de di-2-piridil cetona saliciloilhidrazona (DPKSH) em resinas amberlite xad-2 e xad-7. Extração de íons cobre em fase sólida envolvendo a xad-7 modificada com DPKSH

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

Di-2-pyridyl ketone salicyloylhydrazone (DPKSH) is a hydrazone which forms coordination compounds with several metallic ions. Amberlite XAD-2 and XAD-7 resins are non-ionic polymers which can be used to pre-concentrate metallic ions. Adsorption of DPKSH onto these polymeric matrices was investigated using the spectrophotometry. The amount of DPKSH adsorbed onto the resins was calculated as the difference between the initial concentration and the remained concentration in the supernatant solution, after the contact with the solid phase at different intervals of time. Kinetic models of pseudo-first and -second orders and intra-particle diffusion model were applied on experimental data collected from the kinetic study. Other experiments carried out under a constant time, but changing the initial DPKSH concentration, led to experimental data which were applied to three different isotherm models (Langmuir, Freundlich and Dubinin-Radushkevich) and some thermodynamic parameters were calculated and used to describe the adsorption. For XAD-7 a more complete kinetic study was carried out including different initial concentrations of DPKSH. The resin XAD-7 modified with DPKSH was then applied to study the retention of Cu(II) ions using three differents systems: (a) direct spetrophotometry; (b) a glass column filled with the modified resin and (c) using the flow injection analysis (FIA) with a mini-column partially filled with the solid phase. Finally, Cu(II) was determined in commercial and synthesized samples of sugar cane brandy.

ASSUNTO(S)

brandy dpksh adsorção adsorption aguardente dpksh xad-7 cinética kinetic isotermas isotherms xad-7

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