Hostname: page-component-7bb8b95d7b-5mhkq Total loading time: 0 Render date: 2024-09-18T03:22:21.490Z Has data issue: false hasContentIssue false

Sample Homogeneity and Representation in X-Ray Fluorescence Analysis of Foods*

Published online by Cambridge University Press:  06 March 2019

K. K. Nielson
Affiliation:
Rogers and Associates Engineering Corporation Salt Lake City, Utah 84110
V. C. Rogers
Affiliation:
Rogers and Associates Engineering Corporation Salt Lake City, Utah 84110
A. W. Mahoney
Affiliation:
Utah State University Department of Nutrition and Food Sciences Logan, Utah 84322-8700
Get access

Extract

Method validation is vital for regulatory and nutrient analysis of foods, and imposes criteria for representative sampling and analysis along with more common requirements for precision and accuracy. When solid food samples are directly analyzed by x-ray fluorescence (XRF), they must be homogeneous on a mass scale at least similar to that penetrated by the interrogating and fluorescent x-ray beams. This mass varies with x-ray energy, and hence with the elements being determined, and few data are available documenting the scale on which homogeneity can be assured. This paper examines the effective sample masses that are represented in measuring 21 different elements in pelletized dry food samples, and also the homogeneity of mimerous foods and biological standard reference materials.

Type
Research Article
Copyright
Copyright © International Centre for Diffraction Data 1985

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

*

This work support'ed in part by PHS Grants 1-R43-CA38519-01 and 5-P01-CA34243-02, National Cancer Institute, DHHS.

References

1. Horwitz, W., “ Evaluation of Analytical Methods Used for Regulation of Foods and Drugs”, Analytical Chemistry, 54, 67A-7 6A. 1982.Google Scholar
2. Beecher, G.R. and Vanderslice, J.T., “Determination of Nutrients in Foods: Factors That Must Be Considered”, Modern Methods of Food Analysis, eds., Stewart, K.K. and Whitaker, J.R., WestPort, CT: AVIPublishing, p. 29-55, 1984.Google Scholar
3. Mahoney, A.W., etal., “Nutrient Composition of Foods Obtained from Retail Outlets in Utah”, Utah Agricultural Experiment Station Research Report 53, Logan, Utah, November 1980.Google Scholar
4. Nielson, K.K. and Rogers, V.C., “Comparison of X- ray Backscatter Parameters for Complete Sample Matrix Definition”, Advances in X-ray Analysis, 27, 449 -457, 1984.Google Scholar
5. Nielsonand, K.K. Rogers, V.C., “AccurateX- rayFluorescence Analysis of EnvironmentalMaterialswithoutStandards”, Trans. Am, Nucl. Soc. 49, 146147, 1985.Google Scholar
6. Li, J.-C.R., “ StatisticalInference”, AnnArbor; EdwardsBros., Inc., 1964.Google Scholar
7. U. S. DepartmentofCommerce, NationalBureauofStandards”, CertificateofAnalysis, “ fortheStandardReferenceMaterials: TomatoLeaves, RiceFlour, WheatFlour, Kon-FatMilkPowder, Oyster Tissue, OrchardLeaves, CitrusLeaves, PineNeedles, andBovineLiver.Google Scholar