Routine method for the determination of trace amounts of ²²⁶Ra in urine by alpha spectrometry

²²⁶Ra is considered one of the most radio-toxic 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. (authors)