ROUTINE METHOD FOR THE DETERMINATION OF TRACE AMOUNTS OF 226Ra IN URINE BY ALPHA SPECTROMETRY.

226Ra is considered one of the most radiotoxic naturally occurring radionuclides. A new routine method was developed to measure traces of 226Ra in urine. Radium was pre-concentrated from a 2 l urine sample using manganese oxide (MnO2) particles. The MnO2 precipitate was dissolved and the organic matter was broken down. Then, potential radiological interferents were removed using DGA and AGMP1 stacked resin columns. A barium sulphate (BaSO4) micro-precipitation was performed before measuring the sample by alpha spectrometry. A good recovery of 60 ± 10% and excellent alpha resolution were obtained. The minimum detectable activity (MDA) was 0.2 ± 0.1 mBql-1. The method was validated using spiked samples and can be completed in 5 hours.