An In-House X-ray Fluorescence Spectrometer Development for In Vivo Analysis of Plants

X-ray fluorescence spectroscopy (XRF) is an analytical technique employed to determine the elemental composition of diverse materials. Due to its nondestructive nature and direct analysis that requires little or no sample preparation, it has been particularly useful for investigating the mineral composition of plants and soil. However, commercially available XRF benchtop equipment often restricts this type of experiment in plant science due to the volume of the sample chamber and the source–detector geometry. To overcome this problem, we developed an XRF setup that prioritizes in vivo-based experiments. The equipment is equipped with a 4 W Ag X-ray tube and a silicon drift detector. The detection limits are comparable to those of commercial instruments and suitable for evaluating plant tissues. Finally, a case study using tomato plants as a model species and rubidium (Rb⁺) and strontium (Sr²⁺) as tracers for potassium (K⁺) and calcium (Ca²⁺), respectively, demonstrated their feasibility for long-term in vivo analysis. Therefore, the present XRF system stands out as a viable and cost-effective tool for assessing the absorption and transport of minerals in plant tissues probed by time-resolved in vivo X-ray spectroscopy.