Evaluation of procedures for 226Ra determination in samples with high barium concentration by α-particle spectrometry

The γ emitter 133Ba is the most often used tracer in determination of 226Ra by α-particle spectrometry. If the source for α-particle spectrometry is prepared by microcoprecipitation, a high Ba concentration causes a thicker source layer which results in reduced counting efficiency due to self-absorption on the α spectrometer and consequently lower result for 226Ra, while not effecting the measurement of 133Ba in γ-ray spectrometry. If the electrodeposition is used, recoveries of deposited Ra and Ba are not necessarily the same and impurities of other α emitters may interfere with the α spectrum.