Isotopic analysis of plutonium in foods by inductively-coupled plasma mass spectrometry

Pu isotopes in various foods were detected using a quadrupole ICPMS and Aridus II desolvation nebulizer. The method has ability to detect ²³⁹Pu and ²⁴⁰Pu at concentrations of ~52 pg/kg (0.12 Bq/kg) and ~9.5 pg/kg (0.08 Bq/kg) as well as ²⁴⁰Pu/²³⁹Pu ratio in <8 h after receiving the samples. Foods were wet-ashed followed by DGA extraction for eliminating matrix, isobaric, and polyatomic interferences. A UH⁺ formation rate <10⁻⁵ and a 5-fold enhanced sensitivity for Pu was achieved after system optimization. - Highlights: • Rapid method using a quadrupole ICPMS, validated for screening Pu isotopes in food. • Removing matrix/isobaric interferences by DGA resin aids high-throughput analysis. • Significant UH⁺ reduction and increased sensitivity for Pu detection are achieved. • Adequate Pu isotopic results for a batch of 8 samples are obtained within 8 h.