Determination of sampling constants in NBS geochemical standard reference materials
Recently Filby et al. showed that, for several elements, National Bureau of Standards (NBS) Fly Ash standard reference material (SRM) 1633a was a suitable reference material for microanalysis (sample weights <10 mg). Three proposed NBS clay SRMs 97b, 98b, and 679 have been analyzed by instrumental neutron activation analysis (INAA) using sample weights of 100 to 1000 ..mu..g and no sampling variance could be determined from the overall experimental variances for samarium, lanthanum, scandium, thorium, chromium, arsenic, and hafnium contents. The sampling constant, K/sub s/, determined from the subsampling variance (S/sub s/%)/sup 2/, and the mean sample weight, W vector, K/sub s/ = (S/sub s/%)/sup 2/W vector, could not be determined from these data because it was not possible to quantitate other sources of error in the experimental variances. K/sub s/ values for certified elements in geochemical SRMs provide important homogeneity information for microanalysis. For mineralogically homogeneous SRMs (i.e., small K/sub s/ values for associated elements) such as the proposed clays, it is necessary to determine K/sub s/ by analysis of very small sample aliquots to maximize the subsampling variance relative to other sources of error. This source of error and the blank correction for the sample container can be eliminated by determining K/sub s/ from radionuclide activities of weighed subsamples of a preirradiated SRM.
- Research Organization:
- Washington State Univ., Pullman
- OSTI ID:
- 6714468
- Report Number(s):
- CONF-861102-
- Journal Information:
- Trans. Am. Nucl. Soc.; (United States), Vol. 53; Conference: American Nuclear Society and Atomic Industrial Forum joint meeting, Washington, DC, USA, 16 Nov 1986
- Country of Publication:
- United States
- Language:
- English
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ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
FLY ASH
ACTIVATION ANALYSIS
SAMPLING
ARSENIC
CHEMICAL ANALYSIS
CHROMIUM
DATA COVARIANCES
ERRORS
GEOCHEMISTRY
HAFNIUM
LANTHANUM
SAMARIUM
SCANDIUM
STANDARDS
THORIUM
US NBS
ACTINIDES
AEROSOL WASTES
ASHES
CHEMISTRY
ELEMENTS
METALS
NATIONAL ORGANIZATIONS
RARE EARTHS
RESIDUES
SEMIMETALS
TRANSITION ELEMENTS
US DOC
US ORGANIZATIONS
WASTES
400101* - Activation
Nuclear Reaction
Radiometric & Radiochemical Procedures