The simultaneous analysis of chlorine-36, sulfur-35 and phosphorous-32 in urine

A method has been developed for the simultaneous analysis of phosphorus-32, sulfur-35, and chlorine-36 in urine. The sample must be divided for the analysis; therefore, at least 500 mL of urine is required. Chlorine-36 is estimated by counting AgCl after interferences have been removed by Fe(OH)3, Ca3(PO4)2, and BaSO4 precipitations. Sulphur-35 is estimated as BaSO4 and phosphorus-32 is estimated as BiPO4 after interferences have been removed by cation exchange and coprecipitation. Cross-contamination of the radionuclides is negligible and the chemical recoveries and limits of detection are as follows: Cl-36, 90 percent (269 mBq); S-25, 95 percent (144 mBq); P-32, 70 percent (38 mBq)