Abstract
When the amperometric titration method is used for end-point detection in the continuous coulometric titration, a linear titration curve is obtained, showing that the relationship between the concentration of sample and the electrolytic current is linear, even if the power source for electrolysis is obtained from the out-put of a D. C. amplifier.
Also the voltage sensitivity at the working point does not depend upon the concentration of the component to be determined in the sample solution. This fact is very fortunate in the examination of the transition phenomena of the titrator. As the indicator current is converted into voltage by means of passing through resistance, any sensitivity of voltage (the slope of the titration curve) can be easily selected by changing the value of resistance.
In the present paper the principle of continuous coulometric titration with amperometric end-point detection is considered theoretically, and the differences between this method and that with potentiometric end-point detection is discussed.
As an experiment a dilute solution of arsenous acid is continuously titrated, and recorded with coulornetrically generated bromine. The linearity between the concentration of arsenous acid and the electrolytic current is better than that obtained by the method with potentiometric end-point detection, so that its reproducibility of results is good.
