Jaroslav Heyrovský (born December 20, 1890, Prague, Bohemia, Austro-Hungarian Empire [now in Czech Republic]—died March 27, 1967, Prague, Czechoslovakia) was a Czech chemist who received the Nobel Prize for Chemistry in 1959 for his discovery and development of polarography.
Educated at the Charles University (Universita Karlova) of Prague and at University College, London, Heyrovský worked in London under Sir William Ramsay and F.G. Donnan. After holding several posts at the Charles University, he became professor and director of the department of physical chemistry (1926–54), and he was director of the Polarography Institute at the Czechoslovak Academy of Sciences (1950, 1952–63).
The work that eventually led to the discovery of polarography was begun in London at Donnan’s suggestion. Polarography is an instrumental method of chemical analysis used for qualitative and quantitative determinations of reducible or oxidizable substances. Heyrovský’s instrument measures the current that flows when a predetermined potential is applied to two electrodes immersed in the solution to be analyzed. Within 10 years of the demonstration of the first polarograph (1924) the method was in common use. Heyrovský’s monograph Polarographie appeared in 1941.