Plant science - Inorganic element imaging on a leaf using micro-XRF

A wide range of elements are present in plants. Some elements exist to play important roles as plant nutrients or enzymes, and some elements accumulate unexpectedly due to environmental pollution. While it is important to understand the bulk concentrations of individual elements from a nutritional and ecotoxicological perspective, the distribution of elements is also important for a better understanding of the mechanisms of metabolism and uptake in plants.

micro-X-ray fluorescence spectroscopy (micro-XRF) is an excellent elemental imaging tool for plant science due to the following unique aspects that meet the needs of plant science.

• Non-destructive and non-invasive approach, even without sample pre-treatment.
• Simultaneous detection of multiple elements without prior information, making it helpful even for unknown sample analysis.
• The availability of the X-ray beam under non-vacuum conditions, so that it can be used even for moisture-containing plant samples.

The image below shows the distribution of common elements (K, Ca and S) in a leaf of Brassica oleracea using the XGT-9000 X-ray analytical microscope, a micro-XRF from HORIBA Ltd. Thanks to the imaging capability of micro-XRF, it reveals that different elements are distributed in different parts of the leaf.