Assessment of radioactivity for 24 hours urine sample depending on correction factor by using creatinine

Assessment of intake and internal does requires knowing the amount of radioactivity in 24 hours urine sample, sometimes it is difficult to get 24 hour sample because this method is not comfortable and in most cases the workers refuse to collect this amount of urine. This work focuses on finding correction factor of 24 hour sample depending on knowing the amount of creatinine in the sample whatever the size of this sample. Then the 24 hours excretion of radionuclide is calculated assuming the average creatinine excretion rate is 1.7 g per 24 hours, based on the amount of activity and creatinine in the urine sample. Several urine sample were collected from occupationally exposed workers the amount and ratios of creatinine and activity in these samples were determined, then normalized to 24 excretion of radionuclide. The average chemical recovery was 77%. It should be emphasized that this method should only be used if a 24 hours sample was not possible to collect. (author)