Rapid determination of 226Ra in urine samples.

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