| Autor: |
Marsden, Olivia J., Livens, Francis R., Day, J. Philip, Fifield, L. Keith, Goodall, Phillip S. |
| Zdroj: |
Analyst; May 1, 2001, Vol. 126 Issue: 5 p633-636, 4p |
| Abstrakt: |
236U is produced only by neutron irradiation of uranium and therefore is potentially useful as a marker for anthropogenic uranium in the environment. Accelerator mass spectrometry (AMS) provides a technique for the determination of very low concentrations of actinide nuclides, and has now been applied to the determination of 236U ∶ 235U ratios in an intertidal sediment core collected from the North Irish Sea. Combining measurements of the 238U mass concentrations calculated from alpha spectrometry with 238U ∶ 235U ratios from ICP-MS and 236U ∶ 235U ratios from AMS has allowed the estimation of the mass concentrations of 236U in the sediments. 236U mass concentrations are in the range 10−8 to 10−9 g kg−1, and 236U ∶ 238U atom ratios in the range from 10−5 to 10−6, well above natural baseline levels. Uncertainties based on propagation of measurement errors were less than ±10% although ±15% is perhaps a more realistic estimate of overall uncertainty. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
|
