Rapid Determination of 226Ra in Water Samples
Summary of Method
226Ra is separated from up to 1 liter water samples and measured by alpha spectrometry. Radium is precipitated from samples with calcium carbonate. The calcium carbonate precipitate is dissolved in hydrochloric acid, and cation exchange chromatography is used to purify radium and barium from matrix ions. Eichrom DGA Resin is used to remove other alpha emitting nuclides from radium. Samples are prepared for radium
measurement by alpha spectrometry using barium sulfate micro-precipitation method onto Eichrom® Resolve Filters. Sample preparation, including alpha spectrometry source preparation, for batches of 12-24 samples can be completed by a single operator in as little as 3-4 hours. Yields can be traced with 133Ba by gamma spectrometry or 225Ra(229Th) by alpha spectrometry. If tracing with 225Ra, >8 hours of ingrowth time for the alpha emitting 217At daughter of 225Ra is required prior to measurement by alpha spectrometry.