A FURNACE FOR COMBUSTION OF BIOLOGICAL MATERIAL CONTAINING TRITIUM AND CARBON-14 LABELED COMPOUNDS

A furnace is described for the combustion of wet samples of biological materials containing compounds labeled with 14C or 3H. These samples, which may weigh up to 1 gm wet weight, are completely burned and the oxidation products absorbed within 5 min. The furnace is easy to constuct from inexpensive materials and is simple to operate. It is designed both for laboratories routinely assaying many samples and for those in which such equipment might be required only on rare occasions. Experiments are described in which recovery of 3H was 99.4% and of 14C was 98.3%. Samples withdrawn at random from a routine metabolic trial showed recoveries of 14C at least as good as those by the Schöniger method of combustion. Doubly labeled materials may be counted if the specific activities of the two isotopes are chosen such that the tritium has the higher activity. © 1968.