Optimization of a glancing angle for simultaneous trace elemental analysis by using a portable total reflection X-ray fluorescence spectrometer

By using a portable total reflection X-ray fluorescence spectrometer with a 1 W X-ray tube, a specimen containing nanograms of Ca, Sc, Ti, V, Cr, Mn, Fe. and Ni is measured at several glancing angles of incident X-rays. continuum X-rays are used as the excitation Source. The intensities of the spectral background which degrades sensitivity to trace elements are decreased with a decrease of the glancing angle, and all these elements are detected at the glancing angle of 0.13 degrees smaller than the critical angle for total reflection of the incident X-rays (0.20 degrees). An optimum glancing angle for simultaneously detecting these trace elements is around 0.13 degrees, and detection limits at 0.13 degrees are sub-nanograms to ten nanograms. (C) 2009 Elsevier B.V. All rights reserved.