This review collects the research of the recent years on biological or environmental studies in which Total Reflection X-Ray Fluorescence Spectrometry (TXRF) was used as a chemical analytical technique for quantification of elemental content. Although it is not a novel technique, its applicationin biological and environmental samples has extended in the last years.TXRF is a useful analytical technique used for simultaneous qualitative and quantitative determination of a wide range of chemical elements, from sodium until uranium, including halogens with low matrix interferences. The major advantages of this technique include the small amount of sample requiredand the relative simplicity of sample preparation. Direct analysis of samples is also possible, shortening preparation time, reducing reactive consumption, and simplifying the whole analysis process. Furthermore, the low detection limit makes TXRF an excellent technique for the determination of ultra-trace, trace and major elements (concentrations range from ppb to percent) in environmental and biological samplesFil: Salomone, Vanesa Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín. Instituto de Investigación en Ingeniería Ambiental; ArgentinaFil: Riera, Marina Griselda. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de la Patagonia; ArgentinaFil: Muniain, Claudia Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín. Instituto de Investigación en Ingeniería Ambiental; Argentin
