Rapid determination of ²²⁶Ra in urine samples

A new radiochemical separation method has been developed for rapid analysis of ²²⁶Ra in urine samples. In this method, radium is separated from urine matrix using cation and anion exchange column chromatography. A ²²⁴Ra tracer, is added, together with its parent in the ²²⁸Th standard, for chemical recovery correction. After separation, the sample is precipitated with hydrous titanium oxide (HTiO) and then prepared for counting by creating a thin-layer counting source using BaSO₄ micro-precipitation. The radium isotopes are then counted by alpha spectrometry. Replicate spike and blank samples were analyzed for validation of the procedure. The detection limit was determined to be 0.22 Bq·L^-1 with 4 hours of counting for 20 mL of urine sample. Using this method, the results can be reported within 8 hours turn around time. This method is suitable for quick dose assessment of ²²⁶Ra exposure following a radiation emergency. (author)