A rapid screening method for 32P in urine samples by TDCR Cerenkov measurement.

Based on triple-to-double coincidence ratio (TDCR) Cerenkov measurement, a rapid screening method for the analysis of 32P in urine samples was developed. In this method, urine samples were pre-treated to decompose organics by adding concentrated HCl and H2O2 with heating at 60 °C for 1 h and at 90 °C for 30 min. Acetic acid was then added, and the samples were cooled to ambient temperature before counting in Cerenkov mode using a Hidex 300SLL TDCR liquid scintillation counter. An empirical formula between Cerenkov counting efficiency of 32P and the TDCR value was established to correct for color quenching present in the processed samples. The performance of the method was examined using several sets of urine spike samples, and the measurements agreed very well with the expected 32P activities. The detection limit of 11 Bq L−1 was achieved for 15 mL of urine sample with a counting time of 30 min. [ABSTRACT FROM AUTHOR]