Boletín de la Sociedad Chilena de Química
versión impresa ISSN 0366-1644
RICHTER, PABLO; TORAL, M. INES y MANRIQUEZ, ROBERTO. SISTEMA DE EXTRACCION LIQUIDO-LIQUIDO EN CONTINUO CON SEPARADOR DE FASES TIPO SANDWICH PARA LA DETERMINACION DE COBRE AL ESTADO DEL COMPLEJO COBRE(I)-BATOCUPROINA. Bol. Soc. Chil. Quím. [online]. 1999, vol.44, n.4, pp.451-458. ISSN 0366-1644. http://dx.doi.org/10.4067/S0366-16441999000400008.
In this work a method for determination of copper at low cncentration levels is proposed by using a continuous flow manifold in which the liquid-liquid extraction step for extracting the copper from the aqueous matrix is automated. The analyte is transferred into 1,2 dichloroethane as the colored complex Cu(I)-bathocuproine-counter ion. The manifold also contains a sandwich type membrane separator which is used after the extraction process. This phase separator provides the channel of the outlet organic stream free of aqueous phase, thus avoiding the interference with the transiently detection process at 478 nm. By keeping the chemical and hydrodynamic variables of the method in the optimal condition, it was found that copper can be determined from 64.5 ng/mL to 4000 ng/mL, with a detection limit of 19.3 ng/mL. The repeatability of the method for concentrations of 200 and 1000 ng/mL, expressed as variation coefficient, were of 3.77% and 1.08%, respectively. The sampling rate was 22 h-1. The accuracy of the method was tested by using the certified reference material for elements in waters GBW 08607. The relative error between the found and the certified value was + 2.9%.
Palabras clave : Continuous liquid-liquid extraction; sandwich type phase separator; copper determination; flow injection analysis; water.