An x-ray microprobe beamline was recently developed and commissioned at the Center for Advanced Microstructures and Devices (CAMD), Louisiana State University. It achieves a moderate horizontal and vertical focal spot size of 18.8 µm × 7.0 µm (σ), respectively. The beamline and end-station are designed and optimized to perform (i) spatially-resolved x-ray fluorescence spectroscopy (spectro-microscopy) using the broad intense spectrum of the white synchrotron radiation, and (ii) spatially-resolved x-ray absorption spectroscopy (micro-spectroscopy) in the energy region of 2100eV to 12000 eV. These dual capabilities enable K-edge measurements and mapping, in non-vacuum conditions, of low-Z elements down to Cl, S, and P that are of both environmental interest and technological importance. In this paper, an application of this novel synchrotron tool to elucidate the elemental distribution (microstructure) and chemical state (speciation) of Mn, Cl, S, and P-containing particulates emitted from automobile engines burning methylcyclopentadienyl manganese tricarbonyl- (MMT-) added fuel will be discussed in detail. Future opportunities of this microbeam technique in materials science and materials characterization will also be outlined.