Monochromatic X-ray fluorescence spectroscopy for major and trace element analysis in plant science applications

Determining elemental concentrations in plant tissues is crucial for any study on plant nutrition, physiology, contamination and food safety. However, existing methodologies based on acid digestion of samples coupled to inductively coupled plasma-atomic emission spectrometry (ICP-AES) or plasma-mass spectrometry (ICP-MS) are time-consuming and expensive.

This study introduces an innovative approach for the rapid and reliable analysis of light, transition, and heavy elements in plant samples  using a novel monochromatic X-ray fluorescence (MXRF) spectrometer.

The MXRF method was tested for the detection of 12 different elements, including light elements (K, Ca), transition metals (Mn, Fe, Co, Ni, Cu, Zn), metalloids (As, Se), and post-transition "heavy" elements (Tl, Pb), covering concentrations from 1 to 10,000 mg·kg^-1. The limits of detection and quantification ranged from 1.41 to 4.71 mg·kg^-1. The recovery rates varied from 84.74% to 89.34%, with intraday relative standard deviations (RSD) ≤ 2.31% and inter-day RSD ≤ 4.17%. A method-comparison study using 144 plant samples analysed by both MXRF and ICP-AES showed strong correlations (R ²  > 0.87) for K, Ca, Mn, Fe, Co, Ni, Cu, Zn, As, Pb, and TI.

This study demonstrates the reliability of the MXRF technique for the quantification of K, Ca, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Pb, and Tl in plant samples. Given that MXRF can also be applied to the analysis of elemental concentrations in soil and water samples, future research will focus on refining and establishing methodologies for these sample types.

The online version contains supplementary material available at 10.1007/s11104-025-07984-5.