A small oscillogram and a new method of oscillographic determination based on it were presented. In oscillographic chronopotentiometry to employ Hg working electrode, oscillographic chronopotentiogram formed after classical oscillogram was incised by end depolarizer was called a small oscillogram. Three types of the small oscillogram could be obtained when different end depolarizer was applied to the incision of the classical oscillogram. The theory formula of the small oscillogram was deduced and the adjustment method of the small oscillogram was discussed. Then the oscillogram was applied to the determination of several medicines. Experimental results showed that the oscillographic determination with the small oscillogram could be used to not only the determination of substance whose incision produced near the end of classical oscillogram, but also the convenient, stable, sensitive and selective determination of many substances in a broad potential window. Thus, oscillographic analysis with the small oscillogram can be an important supplement and development for oscillographic analysis with the classical oscillogram.

Key words: electroanalysis, oscillographic analysis, oscillographic chronopotentiometry, oscillographic determination, oscillogram