Analytical Procedure for Measurement of Radioactive Hydrogen (Tritium)

Abstract

A quantitative procedure for the measurement of radioactivity due to H3 depends upon insertion of hydrogen gas in a quartz ionization chamber attached to a Lauritzen electroscope. Radioactive analysis of organic compounds containing Hs is based on combustion to water and the quantitative conversion of this water to hydrogen. A procedure for obtaining tritium water samples of high specific activity is described. A, Ha storage bulb (5 liters) J. Reaction flask in position to break B. Storage bulbs (500 cc.) C. Standard sample storage bulb K. Reaction flask with Mg-Hg amalgam (1 liter) L. U-tube with water sample containing D. Mixing chamber tritium E, Ionization chamber attached

Principles of Isotope Dilution Assays

“…Media containing labeled components of known specific activity can be assayed for these components by addition of a known amount of nonradioactive compound to act as carrier. This is Case II of the Henriques and Margnetti paper (24), and is commonly applied in metabolism studies and for the identification and assay of metabolites, as pointed out by Radin (43).…”

“…As recently as 1946, in a paper (24) on isotope dilution procedures with radioactive tracer compounds, it was necessary to illustrate the applicability of the method with synthetic mixtures of phenyl sulfone, sulfoxide, and sulfide, although stable isotopes had been employed in biological studies (43). Since then, the method has been applied to so wide a variety of compounds and media that justification of a principle based upon synthetic mixtures is no longer necessary.…”

Analytical Method for Determination of Long-Life Carbon C14

“…Two independent series of dilutions were measured. As in previous investigations (4), the data are presented in terms of the following equation: where d is the distance traversed by the electroscope fiber in time t, s indicates the sample, b denotes background, and (d/t)b is the average background rate of fiber discharge. The usual distance traversed by the fiber during measurements was 10 small divisions, although no samples were measured for periods longer than about 1 hour.…”

Procedure for Routine Assay of Tritium in Water

“…Because excellent papers have appeared recently on reduction of organic compounds to gas for tritium assay (8) and on ion current measurement {1, 9) this procedure is limited to reducing water and to transferring the gas to an ionization chamber. This is a simplification of the procedure described by Henriques and Margnetti (4). EXPERIMENTAL Equipment and Materials.…”