Radium (Ra) isotopes are important from the viewpoints of radiation protection and environmental protection. Radium is routinely analyzed in drinking water. Radium isotopes can be analyzed by different analytical methods based on gamma spectrometric measurements or alpha spectrometry. Modern gamma spectrometry systems are typically operated via computer software applications. In this study, the LabSOCS (Laboratory Sourceless Calibration Software) mathematical efficiency calibration software is used. An improved method was developed to determine radium isotopes from water using gamma spectrometry after micro-coprecipitation as lead (radium) sulfate method for radiochemical separation (Pb(Ra)(Ba)SO₄). This method was successfully modified to allow direct determination of ²²⁶Ra and ²²⁸Ra by gamma spectrometry. However, large volumes of samples and/or long waiting time (20 days), before radioactive equilibrium is established, are required for accurate ²²⁶Ra activity concentration determination. The amounts of ²²⁶Ra and ²²⁸Ra on the sample were quantified by using gamma spectrometric analysis for its 186 keV gamma emission, 351.9 (²¹⁴Pb), 295.2 (²¹⁴Pb), and 609.3 (²¹⁴Bi), 1764.5 (²¹⁴Bi) and for ²²⁸Ra can be nonetheless achieved via its daughter nuclide ²²⁸Ac in 911.2 and 969 keV gamma emission. The radiochemical recovery was 93% and 100% for ²²⁶Ra and ²²⁸Ra, respectively. The Minimum Detectable Activities (MDAs) for 8L of sample and a measuring time of 2.3 days for ²²⁶Ra and ²²⁸Ra were calculated. The best results were obtained when the herein described method was combined with LabSOCS calculations.

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