Extração liquido-liquido em sistema de analise em fluxo monossegmentado

AUTOR(ES)
DATA DE PUBLICAÇÃO

2000

RESUMO

The main objective of this work was to enlarge the knowledge about the recently proposed Monosegmented Liquid-Liquid Extraction System, allowing its analytical improvement. In this kind of analytical mechanization, the aqueous sample is introduced in a glass tube which, at a given pH (>8), will retain the metallic íons. Subsequently, a segment of the organic phase follows the sample monosegmented, removing the species previously adsorbed on the glass surface. The effect of the composition of the organic phase on the extraction of Cu(II), Zn(ll) and Cd(ll) was investigated. The composition was altered by adding different amounts of ethanol in toluene, chloroform and carbon tetrachloride. Three ligands (ditizone, 1-2-pyridilazo)-2 naphtol (PAN) and sodium diethilditiocarbamate (Na-DDTC) were also investigated along with the effect of pH of the aqueous phase. The presence of ethanol in the organic phase presents a remarkable effect on the extraction efficiency. Its presence is mandatory if ditizone and Na-DDTC are used as extracting agent. The extraction efficiency also increase with the increase of the pH of the aqueous phase as the active sites of the glass tube surface become avariable. The system has been applied for the determination of Zn(ll) in medicine showing a mean precision of 2.1% and accuracy of 4.4%.

ASSUNTO(S)

medicamentos extração (quimica) zinco

ACESSO AO ARTIGO

Documentos Relacionados