ABSTRACT
The quantitative analysis of chemical elements plays an important role in the Biomedical, since these elements may be essential to the physiology of the biological tissue. Several diseases are associated with a deficiency or excess of these elements, interfering with the metabolism of human beings. Elements such as phosphorus (P), sulfur (S), potassium (K), chlorine (Cl), iron (Fe), zinc (Zn), copper (Cu), bromine (Br), manganese (Mn), nickel (Ni), and chromium (Cr) are responsible for biochemical and physiological processes. Furthermore, non-essential elements such as lead (Pb), cadmium (Cd), silver (Ag), etc., even in small concentrations produce toxic effects, which may lead the individual to death (Santos & Anjos, 2009). The X-ray fluorescence (XRF) is a physical phenomenon that occurs in the process of transition electron orbitals. The analysis by X-ray Fluorescence is a non-destructive analytical technique based on the measurement of the intensities (the number of X-rays detected by unit time) of the characteristic X-rays
emitted by elements that constitute one sample (Klockenkamper & Bohlen, 1996).The X-ray beam on the sample and focuses on the process of interaction of X-rays with the sample occurs release of electrons bound to the atom, and consequently less bound electrons in the outermost orbitals migrate to these orbitals with “holes” left by electrons that have been released. The result of this process is the release of energy as electromagnetic radiation called characteristic X-rays. The energy of the emitted radiation is represented by the difference of the energies of electrons in the outermost orbital and orbital energy of the electrons in the innermost. This energy difference is characteristic of each element (This can be used as an elemental XRF signature). Thus, by detecting the radiation that is emitted in the process of interaction we have the signatures of the elements in the sample represented in the XRF spectrum (Lachance & Claisse, 1995).
