Total Reflection X-ray Fluorescence Analysis (TXRF) is accepted as a powerful analytical tool. TXRF is basically an energy-dispersive technique with the sample excitated in total reflection geometry. Simultaneous detection of almost all chemical elements and lower limits of detection for medium Z elements in the range of a few hundred fg are achievable at optimized excitation conditions. Aqueous and acidic solutions are the preferred sample types, so a lot of applications in the life sciences are given. For solids and other samples, special preparation techniques are required.