Production and Use of Nitrogen-15 in German Agricultural, Biomedical and Ecological Research -A Historical Review-

Abstract

The history of production and application of the stable nitrogen isotope¹⁵N in Germany is mainly part of the history of the former Institute of Stable Isotopes, later a part of the Central Institute of Isotope and Radiation Research (Zentralinstitut für Isotopen-und Strahlenforschung) in Leipzig. In 1956, after a relatively large fractionation during isotopic exchange in the system NO/HNO₃ was reported by SPINDEL and TAYLOR, the construction of an isotope enrichment plant was planned and started work in 1958 on a laboratory scale. The prodution of ¹⁵N-labelled material in the institute started in 1960, followed in 1968 by the start of a separation plant in Wolfen as a branch of industrial fertilizer production. The economy was optimized by feeding back the ¹⁵N decreased efflux to the fertilizer production line.

The material produced was used for studies at home and abroad. Close contacts with the IAEA (International Atomic Energy Agency, Vienna) and the development of an easy-to-handle optical instrument for ¹⁵N measurements were the basis for a wide application in agriculture and medicine.

As a result of German reunification fertilizer production in Wolfen was stopped, and consequently the successful ¹⁵N separation plant had to be closed. A broad spectrum of ¹⁵N-labelled compounds, however, is being produced also today in Berlin and is purchased by Chemotrade, Leipzig.

In the Western part of the country stable isotopes were not produced, but could be purchased on the world market at prices far below the realistic economic costs. At that time research was not coordinated centrally, until the lack of common information was counteracted by the foundation of the Working Group on Stable Isotopes in Mainz in 1977. A similar group in Eastern Germany had been at work since 1959, but no direct contact between the two groups had existed for political reasons.

Key Words:

• Application
• Germany
• history
• Leipzig
• nitrogen 15
• production
• review