Immediately before analysis, serum samples were thawed
and water extracted by heat distillation (Ortiz et al., 1978).
The specific activity of tritium in 100 ml of the distillate was
determined in triplicate in 10 ml of scintillation cocktail
with a liquid scintillation counter (Beckman LS 3801)
along with a dilute HTO standard to calculate the activity
of tracer injected. Total body water (TBW; kg) was
determined as the activity of injected isotope divided by
the activity in the post-equilibrium samples.