The online removal of dissolved oxygen from aqueous solutions used in voltammetric techniques by the chromatomembrane...

The applicability of the chromatomembrane method for the removal of dissolved oxygen from solvents used in voltammetric measurements was investigated. The chromatomembrane cell combined with a flow-through system allows an online deaeration of solutions. These experiments employed a mercury film electrode as working electrode and differential pulse anodic stripping voltammetry as the measuring method. Different eluents with adequate supporting electrolyte (without analyte) were measured to determine the background current, whether any contribution of oxygen is detectable. Voltammograms of eluents deaerated with the chromatomembrane method are compared to those of eluents purged with nitrogen for several minutes immediately before the measurement. No differences in the background currents can be observed when defined flow rates of eluent and nitrogen are maintained. Determinations of cadmium and lead even indicate the high efficiency of this method.