A rapid automatic method for the determination of oxygen in organic substances, using coulometry at controlled potential.

An Unterzaucher apparatus for the determination of oxygen in organic compounds is used. The iodine vapour formed in the anhydroiodic acid tube is led by a stream of nitrogen to the cathodic chamber of an electrolysis cell. Here the iodine is reduced at controlled potential at a rotating Pt-eiectrode. The amount of electricity used is determined by an electronic integrator and read from a digital voltmeter. For weights of samples in the range 0.5-6 mg the standard deviation is about 0.08% oxygen.