Abstract
Recently, a variety of methods have been developed for the determination of oxygen in liquid media by polarography and voltammetry. In many of those, however, electrolytic current is to be compared with the oxygen content in solution determined by an absolute quantitative method such as Winkler's method. Coulometry is a means for an absolute measurement of depolarizers in electrolytic solution and for giving the value determined purely electrochemically. Hanamura has devised a current-coulomb recorder (I-Q Recorder) which enables to integrate a micro intensity of current while linear characteristic of the integrating mechanism being maintained, and proved that the recorder is very useful for coulometric determination of micro amounts of metals. Since amounts of electricity (Q) consumed in electrolysis is a linear function of electrolytic current (I), i.e. Q=coast.×I according to Lingane's equation, an I-Q curve recorded by this instrument is essentially to be a straight line. The authors attempted to apply I-Q Recorder to coulometric analysis of oxygen and found that oxygen dissolved in solution could be determined very easily with precision of ±2% by the instrument incorporated with a novel type of electrolytic cell designed for this purpose.
