A new, automatic procedure developed to convert tritium in HTO into hydrogen for subsequent on-line gas counting is described.
The water containing tritium is introduced onto a column prepared from molecular sieve-5A and heated to 550 °C. The tritium
is transferred by isotopic exchange into hydrogen flowing through the column. The radioactive gas is led into an internal
detector for radioactivity measurement. The procedure is free of memory effect, provides quantitative recovery, with analytical
reproducibility better than 0.5% rel. at a preset number of counts. Application of the procedure in automatic isotope gas
analysis of organic materials labelled with tritium will be described in subsequent papers (Parts II and III).