Polarograph

Part of speech: noun

Definitions

1. An electrochemical instrument that measures the concentration and properties of substances by recording the electric current flowing through a solution as the applied voltage is gradually changed
2. A device used in analytical chemistry that determines the identity and amount of chemical compounds by observing how current varies when voltage is applied to a liquid sample with a mercury drop electrode
3. An apparatus that analyzes solutions electrochemically by plotting the relationship between applied electrical potential and the resulting current to identify and quantify dissolved substances

Etymology: Jaroslav Heyrovský, a Czech chemist working in Prague, built the first such device in 1924 with the help of Masuzo Shikata, a visiting Japanese chemist. It measured the electric current flowing through a solution as the voltage was steadily varied, and it drew the resulting curve automatically on paper. That self-drawn curve gave the instrument its name, which joins "polar", from the polarization of the electrodes that the measurement depends on, to the Greek "graphein", "to write". Heyrovský's method came to be called polarography, and he received the Nobel Prize in Chemistry in 1959 for it.

Synonyms: electrochemical analyzer