The optimization of the estimation of carbon-14 in urine

The urinalysis method for carbon-14 currently used by the bioassay laboratory of the Dosimetric Research Branch at CRNL has been tested and optimized for both sensitivity and efficiency. Urine is first treated with an enzyme that catalyses the hydrolysis of urea, the major carbon-containing component of urine; carbon dioxide is then liberated by the measured addition of excess acid and collected in 2-aminoethanol. The aminoethanol can be directly counted by the addition of a liquid scintillation cocktail. This method can be used to measure both the specific activity, (Bq/g-carbon) or the total activity of carbon-14 released from the urine sample