Determination of Pu isotopes in vegetation using a new on-line FI-ICP-DRC-MS protocol after microwave digestion

Abstract

A new protocol for the determination of Pu isotopes in leaves has been developed. The method consists of microwave sample digestion, flow injection on-line preconcentration/matrix separation, sample desolvation and introduction using an APEX unit and elemental determination using ICP-MS with a dynamic reaction cell. The preconcentration and matrix separation was performed using an anion-exchange resin (AG MP-1M). Detection limits as low as 2.9 fg g⁻¹ and 0.46 fg g⁻¹ were obtained for ²³⁹Pu and other Pu isotopes (²⁴⁰Pu, ²⁴¹Pu, ²⁴²Pu and ²⁴⁴Pu), respectively, for 10 g of NIST-SRM 1515, Apple Leaves. The yield recovery of Pu was also determined for different leaf samples collected locally and spiked with a known concentration of ²³⁹Pu and ²⁴²Pu.