CONTINUOUS ADDITION OF REAGENT TECHNIQUE - A NEW APPROACH TO DIFFERENTIAL REACTION-RATE METHODS

The potential of the continuous addition of reagent technique in differential reaction-rate methods was evaluated. The approach was tested on the simultaneous determination of copper and iron through their fast complex-formation reaction with pyridoxal thiosemicarbazone. Mixtures of these metal ions at the sub-μg ml-1 level with copper/iron ratios from 5:1 to 1:2 can be analysed with a precision (relative standard deviation) of 0.25 and 0.45%, respectively. The method was successfully applied to the determination of both metals in serum samples with a purpose-designed reaction mini-chamber. © 1990.