Abstract
Improvements of the detection limit in photon induced X-ray fluorescence analysis are obtained by the reduction of the radiation background at constant excitation conditions. Two methods are presented: 1) Bragg-reflection at 2 ν=90° results in a beam linearly polarized and monchromatic. Positioning the detector at an angle 90° to the direction of the polarized beam suppresses the production of scattered photons from sample and sample carrier into the detector. The use of single crystals instead of amorphous scattering materials increases the intensity of the polarized beam, in some cases up to a factor 104. Detection limits and actually used crystal materials and lattice planes for Braggreflection are given in tables. Samples may be of either form, liquid or solid, no special sample preparation is required. 2) The application of X-ray total reflection on the polished and plane surface of a reflector which serves as the sample carrier reduces the radiation background. In the case of X-ray total reflection there is scarcely a penetration of the X-rays into the reflector material. The penetration depth of some 100 Å in the reflector-substrate can be compared to an extreme thin foil of same thickness. Therefore the reflector-substrate combines its mechanical strenght, its compact and constant geometric form, its chemical resistance and the possibility of easy handling-with the low background properties of ultra-thin foils. Samples should be liquids where the liquid part of the matrix is evaporated and the remaining trace elements are investigated. Both method are capable of detecting elements in the nanogram region.
Similar content being viewed by others
References
E. P. BERTIN, Principles and Practic of X-Ray Spectrometric Analysis, Plenum Press, New York, 1975.
K. K. HERGLOTZ, L. S. BIRKS X-Ray Spectrometry Marcel Dekker Inc., New York and Basel, 1978.
H. AIGINGER, P. WOBRAUSCHEK, C. BRAUNER, Nucl. Instr. Meth., 120 (1974) 541.
T. G. DZUBAY, B. V. JARETT, J. M. JAKLEVIC, Nucl. Instr. Meth., 115 (1974) 297.
P. WOBRAUSCHEK, H. AIGINGER, X-Ray Spectrom., 9 (1980) 57.
H. AIGINGER, P. WOBRAUSCHEK, C. BRAUNER, Detection and Control of Environmental Pollutants, IAEA Symposium SM 205/15 Vienna, 1976.
H. AIGINGER, P. WOBRAUSCHEK, C. BRAUNER, AIAU-Report 75105, 1975.
P. WOBRAUSCHEK, H. AIGINGER, Anal. Chem., 47 (1975) 852.
P. WOBRAUSCHEK, H. AIGINGER, X-Ray Spectrom., 8 (1979) 57.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Aiginger, H., Wobrauschek, P. X-ray fluorescence analysis in the nanogram region with a total reflected and a Bragg polarized primary beam. J. Radioanal. Chem. 61, 281–293 (1981). https://doi.org/10.1007/BF02517414
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02517414