RETROSPECTIVE METHOD VALIDATION AND UNCERTAINTY ESTIMATION FOR ACTINIDES DETERMINATION IN EXCRETA BY ALPHA...

Area of Science:

• Analytical Chemistry
• Radiochemistry
• Occupational Health

Background:

• ISO 17025 accreditation requires method validation and uncertainty estimation for testing laboratories.
• The Bioelimination Laboratory at CIEMAT quantifies alpha emitters in biological samples from radiation-exposed workers.
• Alpha spectrometry is used to measure isotopes such as Plutonium (Pu), Americium (Am), Thorium (Th), Uranium (U), and Curium (Cm).

Purpose of the Study:

• To validate the alpha spectrometry analytical method used for internal radiation monitoring.
• To estimate all sources of uncertainty affecting the quantification of alpha emitters in urine and faecal samples.
• To fulfill technical requirements for ISO 17025 accreditation.

Main Methods:

• Retrospective analysis of data obtained over several years.
• Identification and quantification of all potential sources of uncertainty.
• Calculation of the overall combined standard uncertainty for the analytical method.

Main Results:

• The analytical method for quantifying alpha emitters in biological samples was successfully validated.
• Comprehensive uncertainty estimation was performed, identifying all contributing factors.
• The overall combined standard uncertainty was calculated, providing a measure of method reliability.

Conclusions:

• The laboratory has successfully validated its alpha spectrometry method for internal radiation monitoring.
• The uncertainty estimation process provides a robust assessment of analytical results.
• These steps are crucial for achieving ISO 17025 accreditation and ensuring reliable monitoring of exposed workers.