Klaproth, Martin Heinrich (1743–1817)

German chemist who first identified the elements uranium and zirconium, in 1789, and was the second person to isolate titanium, chromium, and cerium. He was a pioneer of analytical chemistry.

Klaproth was born in Wernigerode, Saxony, apprenticed to an apothecary when he was 16, and in 1771 became manager of a pharmacy in Berlin. He lectured in chemistry at the Berlin School of Artillery from 1792, and when the University of Berlin was founded in 1810 he became its first professor of chemistry.

Klaproth distinguished strontia (strontium oxide) from baryta (barium oxide) and in 1795 rediscovered and named titanium. He isolated chromium in 1797 independently of French chemist Louis Vauquelin, but credited Franz Müller (1740–1825) with the priority for the discovery of tellurium, which Klaproth extracted in 1798 and named. In 1803, Klaproth identified cerium oxide and confirmed the existence of cerium, discovered by Swedish chemist Jöns Berzelius in the same year. He also studied the rare earth minerals.