Tandem Probe Analysis Mode for Synchrotron XFM: Doubling Throughput Capacity

Area of Science:

• Analytical Chemistry
• Materials Science
• Environmental Science

Background:

• Synchrotron-based X-ray fluorescence microscopy (XFM) is a sensitive elemental mapping technique.
• High demand for synchrotron beamtime limits throughput, especially for large samples.
• Diffusive gradients in thin-film (DGT) devices are used for environmental elemental analysis.

Purpose of the Study:

• To develop a method for scanning large DGT gels (170 cm²) using XFM without reducing beamline throughput.
• To introduce a novel tandem probe analysis mode for simultaneous XFM measurements.
• To assess the suitability of different gel materials for XFM analysis.

Main Methods:

• Developed and tested a tandem probe setup with two fluorescence detectors for simultaneous XFM data acquisition.
• Analyzed the beam quality and sample transmittance using various gel materials (bis-acrylamide, polyacrylamide, polyurethane).
• Investigated the use of large DGTs for mapping nutrient diffusion in soil.

Main Results:

• The tandem probe mode effectively doubled XFM throughput by performing two experiments simultaneously.
• Polyurethane gels demonstrated optimal properties for XFM, allowing >99% transmittance and minimal flux variation.
• Successfully mapped analytes in large DGTs for the first time.

Conclusions:

• A novel tandem probe analysis mode significantly enhances synchrotron XFM throughput for large samples.
• Polyurethane DGTs are suitable for XFM analysis, enabling detailed elemental distribution mapping.
• This tandem analysis approach has broad applicability for various XFM experiments with transmissive samples.