AbstractA new approach to problems associated with enhancement effects in XRF analysis, and by analogy to analysis by electron microprobe and PIXE, is discussed. The concept of enhancement as ‘relative excess absorption’ is introduced. This concept allows an arrangement of mass balances in which the concentration of any given element may be derived explicitly from a set of relationships equivalent to fundamental expressions, such as the Lachance–Traill and Tertian equations for monochromatically excited XRF and the Claisse–Quintin equations for polychromatic excitation. In this new approach the values of μk′(λiorEi) may be derived, and carry the meaning of apparent mass absorption coefficients for absorption and enhancement effects characteristic of any given pair of elements. Finally, some obvious convergences between XRF, electron microprobe and PIXE analyses are