Flow-through cell for on-line amperometric determination of Ce(lV) during polymerization reactions.

In this paper, a method is described for the chronoamperometric determination of Ce(IV) in acidic aqueous solutions in order to study the kinetics and the mechanism of polymerization reactions with Ce(IV) as the initiator. The method is based on the FIA principle, in which small samples are injected in a continuous 1.0 mol L(-1) H2SO4 flow, and Ce(IV) is detected chronoamperometrically by reduction at the surface of a gold CDtrode. Such an electrode is made from a commercial CD that has a gold coating acting as a reflecting layer for the laser beam. It was found that a detection limit of 1.5 10(-7) mol L(-1) could be obtained with this method, that high concentrations (order of 10(-2) mol L(-1)) can be detected without IR drop and that the system can be used over several days without renewal or recalibration of the gold CDtrode.