Development and application of analytical method for the determination of low-level Tc-99 by high resolution ICP-MS

An analytical method has been investigated for determining low level Tc-99 in environmental samples by High Resolution Inductively Coupled Plasma Mass Spectrometry (HR-ICP-MS). This analytical method consists of leaching of Tc-99 from soils and/or sediment samples by HNO3 , separation and purification by three stages of solvent extraction with 30% TOA (triotylamine)-xylene. MEK (methyl ethyl ketone) and followed by cyclohexanone. Finally, purified Tc-99 was passed through an annion exchange column to reduce the content of dissolved solids. The solution was adjusted to 1 M HNO3 for introducing into the HR-ICP-MS. This method has been applied to sediment samples from the Esk Estuary, Irish Sea. Information on sedimentary behaviour pf Tc was obtained by comparing inventories with total discharges. The potential affinity to sediment descreased in the order of Pudouble ∼ Am>Np>Cs>Tc, suggesting that Tc is more soluble and mobile than other nuclides in the sediment. (author) 10 refs; 4 tabs; 5 figs