[Background]:During the synthesis process of sodium fluoride[18F] injection

the accelerator-derived impurities including the harmful metal elements and radionuclide impurities may contaminate the injection. [Purpose]: This study aims to systematically evaluate the residual levels of these impurities introduced during cyclotron irradiation and assess the efficacy of quaternary methyl ammonium cartridge（QMA cartridge） purification in eliminating contaminants.[Methods]:Fluoride[18F] ion solutions with varying activities were produced by irradiating H218O in a cyclotron equipped with a niobium target chamber and Havar foil. A portion of each fluoride[18F] ion solution was passed through a QMA cartridge to obtain purified samples. The elemental impurities

radionuclidic impurities

and tritium content in the samples were measured before and after purification using ICP-MS

HPGe

and Liquid Scintillation Counter

respectively. Following this analysis

the sodium fluoride[18F] injection was characterized using the same methods.. [Results]: The results demonstrated that the predominant elemental impurities introduced were Co

Ni

and Mo. More than 17 species of γ-nuclide impurities with half-life over 2 hours were decteted

showing a tendency to increase with increasing levels of irradiation. Additionally

the content of tritium exhibited a concentration of approximately 2 × 10⁻6 in the fluoride[18F] ion solutions. Following purification by the QMA cartridge and subsequent processes

the elemental impurities in the sodium fluoride [18F] injection comply with ICH Q3D limit requirements

with a radionuclidic purity exceeding 99.9999% and tritium not detected. [Conclusions]: Critically

the workflow ensures compliance with pharmacopeial standards

thereby safeguarding the clinical safety of sodium fluoride[18F] injection. Collectively

this study provides a validated framework for controlling irradiation-induced impurities in fluoride[18F]-labelled radiopharmaceutical production.