Synchrotron radiation sources are ideal for developing high intensity, highly-focused X-ray
probes for characterizing the speciation, transport and reactions of trace elements in biotic and
abiotic components. In particular, micro-XRF allows one to image and quantify the distribution
of trace elements in samples with detection sensitivities at the attogram level. Micro-XAS
analysis allows one to quantify oxidation state ratios in heterogeneous earth and biological
materials at spatial resolutions less than 1 micrometer. Coupled X-ray-fluorescence, -
spectroscopy and -diffraction analysis allows one to quantify the abundance and speciation of
elements at trace concentrations and evaluate the mineralogy to which they are adsorbed or
bound. Such information is crucial in understanding element cycling in the environment,
mobility and toxicity of contaminants, and mechanisms of nutrient uptake and partitioning in
plants and other organisms. Applications of X-ray fluorescence microscopy in the Plant and
Soil Sciences will be presented.
