The reaction time optimized by using carbamide as carrier was 1 h. For 80 ml urine, the amount of potassium persulfate used was 10 g. The method recovery rate reached about 100%. Four real urine samples were tested using the optimized method, and the result of activity concentration 14C was 0.32, 0.60, 0.86 and 0.74 Bq/L, respectively.
Conclusions:
The optimized method had good stability, high accuracy and stable experimental result, which could meet the needs of routine radiological detection. The establishment of a quantitative method for 14C in urine sample has improved the methodological system for 14Cmonitoring.