Sir Johan Gadolin of Turku: the grandfather of gadolinium.

Abstract

Acad Radiol 1996;3:S 165-$169 9 1996, Association of University Radiologists J ohan Gadolin was 33 years old in the spring of 1794, when his most important work was published [1]. In 28.5 pages, he carefully described his detailed chemical analysis of a new, black, heavy mineral that had recently been discovered at the Ytterby quarry on the island of Roslaga near Stockholm. A small sample had been given to him by the supervisor of the quarry in 1792. From it, he concluded that 38% of the mineral consisted of a previously undiscovered element. He named this substance ytterbia after the village near the quarry, but the name was soon shortened to yttria. The substance that he discovered was actually yttrium oxide, and it was the first of the so-called rare earths to be discovered and isolated [2]. The mineral from which he had isolated yttrium oxide soon acquired the name gadolinite in his honor. Although Gadolin and other chemists initially believed that he had discovered a new element, in 1808 Sir Humphry Davy showed that metallic earths are oxides, not pure elements. The rare-earth elements caused chemists considerable confusion for the next half century until tile introduction of the spectroscope in 1859 (99 years after Gadolin's birth) and Dmitri Mendeleev's first report of his periodic table in 1870. It was not until 1880, 120 years after Gadolin's birth, that Swiss chemist Jean-Charles-Galinard de Marignac isolated gadolinium oxide. The French chemist Paul-l~mile Lecoq de Boisbaudmn, a codiscoverer of gadolinium oxide, persuaded de Marignac to name this gadolinia. This occurred in 1886, 34 years after Gadolin's death. Pure elemental, metallic gadolinium was first purified in 1935 by French chemist E Trombe [2]. Gadolinium is not particularly rare, ranking 43rd among the elements in abundance, and it is 10 times more abundant than iodine. Among its many uses, it is a fluorescent agent in television screens and X-ray intensifying screens [2]. Since Hanns-Joachim Weinmann's pioneering work in 1981 [3], chelates of gadolinium have been introduced as tile first and, until 1995, tile only commercial paramagnetic contrast media used for magnetic resonance (MR) imaging.