The potential advantages of synchrotron sources for x-ray fluorescence analysis have been discussed by several authors. These advantages include high incident flux, tunable excitation energies using crystal monochromators, and reduction of scattered background due to polarization effects. Minimum detectable limits have both been calculated and measured, and have demonstrated the improvements that can be achieved vising synchrotron sources. In this paper we present results obtained using tunable, monochromatic excitation and a high resolution lithium-drifted silicon, Si(Li), spectrometer for the quantitative analysis of a variety of sample types. Our experiments were designed to investigate the advantages and limitations of tunable monochromatic excitation with respect to optimum sensitivity, accuracy, and elemental selectivity in energy dispersive x-ray fluorescence analysis.