Determination of 226Ra in Urine Using Triple Quadrupole Inductively Coupled Plasma Mass Spectrometry

Measuring 226Ra in urine at low levels is critical for both biomonitoring and radiological emergency response. Here we report a new analytical method to quantify 226Ra, as developed and validated by a simple dilute-and-shoot procedure, followed by Inductively Coupled Plasma-triple quadrupole-mass spectrometry detection using 'No Gas MS-MS' mode. The method provides rapid and accurate results for 226Ra with a limit of detection (LOD) down to 0.007 ng/l (0.26 Bq/l). This LOD is well below the recommended action levels for 226Ra detection in children and pregnant women (C/P) set by the Clinical Decision Guide (NCRP Report #161). Results for 226Ra obtained by this method are within ±7.0% of the target values of standard reference materials spiked in the urine.

Comparison of radium-228 determination in water among Australian laboratories

The National Health and Medical Research Council and Natural Resource Management Ministerial Council of Australia developed the current Australian Drinking Water Guidelines which recommend an annual radiation dose value of 1 mSv year^-1. One of the potential major contributors to the radiation dose from drinking water is radium-228, a naturally occurring radionuclide arising from the thorium decay series. Various methods of analysing for radium-228 in water have been established and adapted by analytical radiochemistry laboratories. Seven laboratories in Australia participated in analysing radium-228 spiked water samples with activity concentrations ranging from 6 mBq L^-1 to 20 Bq L^-1. The aim of the exercise was to compare and evaluate radium-228 results reported by the participating laboratories, the methods used and the detection limits. This paper presents the outcome of the exercise.

Simultaneous determination of 226Ra, 228Ra and 210Pb in drinking water using 3M Empore™ RAD disk by LSC-PLS

A procedure for the rapid and simultaneous determination of ²²⁶Ra, ²²⁸Ra and ²¹⁰Pb in drinking water by means of extraction with a 3M Empore™ Radium RAD disk and liquid scintillation spectrometry is described. The selective elution of ²¹⁰Pb from the RAD disk and a multivariate calibration using partial least squares regression (PLS) are tested as methods to avoid overlap in the spectra between ²²⁸Ra and ²¹⁰Pb. The validated procedure was tested with mixtures of radionuclides and interlaboratory materials; finally, it was applied to natural waters.

228Ra and 226Ra measurement on a BaSO4 co-precipitation source

One of the most commonly-used methods for determination of ²²⁶Ra, particularly in water samples, utilises co-precipitation of Ra with BaSO₄, followed by microfiltration to produce a source for alpha counting. This paper describes two extensions to BaSO₄ co-precipitation methods which enable determination of ²²⁸Ra using the same source. The adaptations presented here do not introduce any contaminants that will affect the separation of radium or alpha counting for ²²⁶Ra, and can be used for re-analysis of already existing sources prepared by BaSO₄ co-precipitation. The first adaptation uses detection of ²²⁸Ac on the source by gamma spectrometry. The detection efficiency is high, allowing analysis of water samples at sufficiently low activity to be suitable in testing for compliance with drinking water quality standards. As ²²⁸Ac grows in quickly, taking less than 2 days to reach equilibrium with the ²²⁸Ra parent, this can also be useful in radiological emergency response situations. The second adaptation incorporates a method for the digestion of BaSO₄ sources, allowing separation of thorium and subsequent determination of ²²⁸Th activity. Although ingrowth periods for ²²⁸Th can be lengthy, very low detection limits for ²²⁸Ra can be achieved with this technique.