DETERMINATION OF AL, CA, V AND MN BY INAA - APPLICATION TO THE REFERENCE MATERIAL IAEA-395 URBAN DUST

Instrumental NAA based on short-lived radionuclides implies high initi al total count rates which change appreciably over the counting period . This in rum necessitates corrections for three negative biases: loss es due to differences in counting time between samples and standards; pile-up losses, and (residual) influence of dead-time. The procedure i s demonstrated for the determination of Al, Ca, V and Mn in the IAEA R eference Material 395 ''Urban Dust''. The obtained data are in good ag reement with the reference values for this material. By limiting the t otal relative dead-time to less than or equal to 25%, statistical unce rtainties are below 5%.