JAMES KING-HOLMES / SCIENCE PHOTO LIBRARY JAMES KING-HOLMES / SCIENCE PHOTO LIBRARY
Spent reaction tubes used in conversion of organic samples to gases in the radiocarbon dating process. The colours are produced by the oxidation and reduction processes. The oxidation reactor tubes contain green chromium trioxide, used to oxidise any carbon and nitrogen containing compounds to carbon dioxide and nitrous oxides respectively, and copper oxide which has been reduced to copper metal performing a similar role to the chromium trioxide. Silver gauze and silver wool layers trap sulphur impurities which show as yellow bands. The chemical layers are separated by glass wool plugs. The blue/black colour reduction tubes contain copper metal which has been oxidise to copper oxide, reducing the nitrous oxides produced in the oxidation reactor to nitrogen gas.
Model release not required. Property release not required.