Evaluation of tea as a matrix in a dual (3H/14C) performance testing program in Canada

Area of Science:

• Radiological protection
• Analytical chemistry
• Bioassay development

Background:

• Urine is the standard matrix for bioassay performance testing programs (PTP) and inter-comparison programs (ICP).
• Human urine presents biosafety concerns, collection challenges, and odor issues, particularly for large-scale programs.
• Previous research demonstrated the potential of tea as a simulated urine matrix for single isotope analysis.

Purpose of the Study:

• To evaluate the efficacy of tea as a simulated urine matrix for dual isotope (Hydrogen-3 and Carbon-14) analysis in bioassay PTP and ICP.
• To extend previous findings on single isotope analysis in tea to a dual-isotope scenario.
• To confirm the compatibility and performance of tea-based simulated urine under established regulatory standards.

Main Methods:

• Tea steeps were prepared and diluted.
• UV-VIS spectroscopy was used to determine appropriate concentrations for simulated urine.
• Tea samples were spiked with known concentrations of Hydrogen-3 and Carbon-14.
• Performance was assessed using the S-106 standard of the Canadian Nuclear Safety Commission.

Main Results:

• Tea samples spiked with both Hydrogen-3 and Carbon-14 (DUAL) demonstrated compatibility as a simulated urine matrix.
• The use of tea in PTP and ICP exercises yielded excellent results, consistent with previous single-isotope studies.
• The method supports the use of tea as a viable and effective alternative to natural urine for bioassay programs.

Conclusions:

• Tea is a suitable and advantageous matrix for simulating urine in bioassay performance and inter-comparison programs.
• The use of tea overcomes the biosafety, collection, and olfactory drawbacks associated with natural urine.
• This study validates tea as a simulated urine matrix for dual-isotope analysis, enhancing its applicability in radiological bioassay.