[A study of the method for microdetermination of proteins using polarographic oxygen maximum (author's transl)].

Oxygen dissolved in solutions is reduced at the dropping-mercury electrode of direct-current polarograph to produce two waves. The first oxygen wave displays a very pronounced maximum under some conditions. The conditions displaying or suppressing the maximum have been demonstrated experimentally. It has been found that proteins have two orders of suppressive power over other biological substances and the amount suppressed is proportional to the concentrations of proteins in lower range of concentrations. A method for microdetermination of proteins has been developed using the phenomenon. The reagent required is sodium chloride alone and oxygen dissolved naturally in a sample solution from air is utilized for the determination. The procedure required is merely to dilute a sample solution to an optimum concentration for the determination with a solution of sodium chloride. The method has been demonstrated to be specific for proteins under a certain condition and to be applicable to hematological, serological and biochemical investigations in the area of medicine.