Analytical Suite Metadata

Chemex (lake sediment) NADNC (U)-flux 1012, d.l.= 0.05ppm

Chemex, lake sediment; neutron activation-delayed neutron activity (uranium)-flux 1012, d.l. 0.05ppm

General Methodology:

Uranium was determined using a neutron activation method with delayed neutron counting.  A detailed description of the original method is provided by Boulanger et al. (1975).  In 1979, modifications related to the irradiation and counting times were introduced.  In brief, a 1 gram sample is weighed into a 7 dram polyethylene vial, capped and sealed.  The irradiation is provided by the Slowpoke reactor with an operating flux of 1012 neutrons/sq cm/sec.  The samples are pneumatically transferred from an automatic loader to the reactor, where each sample is irradiated for 20 seconds.  After irradiation, the sample is again transferred pneumatically to the counting facility where after a 10 second delay the sample is counted for 20 seconds.  Following counting, the samples are automatically ejected into a shielded storage container.  Calibration is carried out twice a day as a minimum, using natural materials of known uranium concentration.  Detection limit = 0.4 ppm.


Boulanger, A., Evans, D.J.R. and Raby, B.F. (1975).  Uranium analysis by neutron activation delayed neutron counting. Proc. Of the 7th Annual Symp of Canadian Mineral Analysts, Thunder Bay, Ontario, Sept 22-23, 1975.

Instrument: unstated

Sample material: solid

Sample weight: 2000 milligrams

Analytical Technique:

Hierarchical classification

Technique >> Radiochemical methods >> Activation analysis >> Neutron activation >> Fission >> Delayed Neutron Counting



Analytical Decomposition:

Hierarchical classification

Decomposition >> None



Analytical Methods:

IndexMethod OrderMethod IDQuantityDetection Limit
1  2168     U_NADNC  0.5

Associated Analytical Packages:

IndexPackage IDPackage Name
1  386     Chemex (NGR lake sediment) AAS (8+4), CVAAS (Hg), LOI500, U
Date modified: