Radiostrontium and radium analysis in low-level environmental samples following a multi-stage semi-automated...

Area of Science:

• Environmental Science
• Radiochemistry
• Analytical Chemistry

Background:

• Radiotoxic isotopes strontium-89 (89Sr), strontium-90 (90Sr), and radium-226 (226Ra) require routine monitoring in Canadian milk and drinking water.
• Existing monitoring methods may lack the sensitivity or efficiency needed for comprehensive environmental surveillance.

Purpose of the Study:

• To develop and validate a novel, semi-automated, and sensitive method for quantifying 89Sr, 90Sr, and 226Ra in environmental samples.
• To adapt the method for simultaneous analysis of these radiotoxic isotopes within a single sample preparation procedure.

Main Methods:

• A two-stage purification process involving strong cation exchange (SCX) chromatography and high-performance ion chromatography (HPIC).
• Quantification of 89Sr via Cerenkov counting and 90Sr through ingrowth of its daughter product 90Y.
• Determination of 226Ra activity using liquid scintillation counting via 222Rn emanation after SCX separation.

Main Results:

• Achieved minimum detectable concentrations (MDCs) of 0.03 Bq/L for 89Sr and 0.02 Bq/L for 90Sr (200 min count).
• Established an MDC of 0.002 Bq/L for 226Ra (100 min count).
• Validated the method using intercomparison samples from the USA Department of Energy MAPEP and IAEA-spiked water samples.

Conclusions:

• The developed semi-automated method provides a sensitive and efficient means for monitoring key radiotoxic isotopes in environmental matrices.
• This technique enhances the capability for accurate assessment of radioactive contamination in Canadian milk and drinking water supplies.