Accounting for Overcounting Induced by 222rn Contamination in 14C Measurements Performed with Liquid Scintillation Counting

This research paper introduces a methodology for estimating overcounting resulting from uranium series radionuclides, with a specific focus on Rn-222 contamination. The method is demonstrated using the Quantulus 1220 (TM) spectrometer. Exponential fitting is employed for the calculations, utilizing a custom algorithm developed in MATLAB (R) R2022b. The proposed method allows for the determination of the sample count rate correction, (FC)-C-14 and radiocarbon age without the need for additional chemical treatment or specialized electronics during liquid scintillation counting (LSC) measurements with the Quantulus 1220 (TM) spectrometer. However, the method does have certain limitations. It requires a significant number of cycles and extended measurement time per cycle, but it can be applied to samples with significant Rn-222 contamination that require rapid C-14 analysis.