Rhod number

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The thiocyanate number (also Rhodanometrische iodine number ) is a fat index and designates the amount of thiocyanates , expressed as a percentage of the equivalent amount of iodine , which to a fat or fatty acid can be added. The rhod number is a key figure for the proportion of unsaturated fatty acids in fats and oils . In contrast to the iodine number , the rhod number does not record any difference between monounsaturated and polyunsaturated fatty acids .

The unsaturated fatty acids react in the presence of an aromatic catalyst with added alcoholate - ions of a polycyclic azo dye . The delocalized double bonds and thus the unsaturation can thus be determined on the basis of the number of heterocyclic aromatics .

The determination of the rhodan number used to be carried out according to the method of Hans Paul Kaufmann by reacting the fat with a rhodan solution (made of lead rhodanide , glacial acetic acid , acetic anhydride and carbon tetrachloride ) and a potassium iodide solution and a sodium thiosulphate solution as an indicator.

Individual evidence

  1. ↑ Eugen Schnelle: The Rhod Number of Fats. 1927.
  2. ↑ Aloys Wilhelm JH Bömer, Adolf Juckenack, Josef Tillmans, Ernst Bames, Benno Bleyer, Johann Grossfeld: Handbuch der Lebensmittelchemie: Volume 4. Fats and oils, lipoids, waxes, resins, essential oils. J. Springer, 1939. pp. 113, 115.
  3. ↑ Georg Lunge: Chemical-technical investigation methods. Volume 4. Chemical-technical investigation methods , edition 8, J. Springer, 1943. pp. 451-452.
  4. ^ PH List, L. Hörhammer: General part. Drug groups I . Springer-Verlag, 2013, ISBN 978-3-642-47985-4 , pp. 388 ( limited preview in Google Book search).
  5. ↑ Georg Arends, Heinrich Zörnig, Hermann Hager, Georg Frerichs, Walther Kern: Hager's handbook of pharmaceutical practice for pharmacists, drug manufacturers, druggists, doctors etc. Medical officer . Springer-Verlag, 2013, ISBN 978-3-662-36329-4 , p. 202 ( limited preview in Google Book search).