Contamination of tritiated glucose tracers

In vivo studies of glucose turnover have been complicated by the occurrence of theoretically impossible negative numbers for endogenous glucose production and it has only very recently been proposed that this could be due to radiochemical contamination of the tracers employed. We have analyzed tritiated glucose infusates purchased over the past 2 years and have found a surprisingly high and variable degree of radiochemical contamination, which could explain the above paradox.