Method for ⁹⁰Sr Analysis in Environmental Samples Using Thermal Ionization Mass Spectrometry with Daly Ion-Counting...

Area of Science:

• Environmental Science
• Analytical Chemistry
• Nuclear Science

Background:

• Accurate quantification of radionuclides like strontium-90 (⁹⁰Sr) is crucial for environmental monitoring.
• Conventional radiometric techniques for ⁹⁰Sr analysis can be time-consuming.
• Advancements in mass spectrometry offer potential for more sensitive and rapid radionuclide detection.

Purpose of the Study:

• To develop and validate a novel analytical method for ⁹⁰Sr determination using thermal ionization mass spectrometry (TIMS).
• To assess the sensitivity and abundance sensitivity of the developed TIMS method for ⁹⁰Sr.
• To validate the method by analyzing ⁹⁰Sr in certified reference materials.

Main Methods:

• Utilized the Isotopx Ltd. Phoenix X62 thermal ionization mass spectrometer (TIMS).
• Employed a Daly ion-counting system for high sensitivity detection of ⁹⁰Sr.
• Determined the abundance sensitivity for the ⁹⁰Sr/⁸⁸Sr ratio.

Main Results:

• Achieved excellent ion beam sensitivity, detecting 1 mBq (0.2 fg) of ⁹⁰Sr.
• Demonstrated an abundance sensitivity of 2.1 × 10^-10 for the ⁹⁰Sr/⁸⁸Sr ratio.
• Successfully determined ⁹⁰Sr in wild berry (IRMM-426) and freshwater lake sediment (NIST-4354) reference materials for the first time using TIMS.

Conclusions:

• The developed TIMS method provides a highly sensitive and faster alternative to conventional radiometric techniques for ⁹⁰Sr analysis.
• The method is capable of measuring low levels of ⁹⁰Sr in environmental samples with high stable strontium concentrations.
• Potential interferences from ⁹⁰Zr and ⁸⁸Sr peak tailing require careful consideration for accurate results.