Wavelength-Dispersive XRF (WD-XRF)
Definition
An XRF configuration that uses an analysing crystal to separate emitted X-rays by wavelength before detection, giving high spectral resolution and low detection limits for major and minor elements.
- Dispersion method
- Analysing crystal separates X-rays by wavelength
- Resolution
- High spectral resolution
- Detection limits
- Low, for major and minor elements
- Contrast
- Higher resolution than energy-dispersive XRF
Common questions
Why choose WD-XRF over energy-dispersive XRF for soil or rock samples?+
The crystal-based wavelength separation resolves closely spaced elemental peaks that would overlap in an energy-dispersive spectrum, which matters when discriminating trace elements in complex geological matrices such as soil used for provenance comparison in trace evidence work.
What is the practical tradeoff for WD-XRF's better resolution?+
Analysis is slower and instrumentation is more complex and costly than energy-dispersive XRF, and WD-XRF typically requires a larger, well-prepared sample and longer acquisition time, making it less suited to rapid screening of many small forensic samples.
Related terms
- Energy-Dispersive XRF (ED-XRF)
- An XRF configuration using a solid-state detector that registers all emitted photon energies simultaneously. Faster and more compact than WD-XRF, enabling portable...
- Fused Bead
- A preparation method where soil is dissolved in molten lithium tetraborate or metaborate flux at around 1100 degrees Celsius to form a...
- Matrix Effect
- The absorption or enhancement of characteristic X-rays by other elements in the same sample, causing apparent concentrations to deviate from true values...
- Pressed Pellet
- A sample preparation form in which finely ground, dried soil is mixed with a binder and compressed under several tonnes of pressure...
- X-Ray Fluorescence (XRF)
- A technique in which a sample is irradiated with a primary X-ray beam, causing its constituent elements to emit characteristic secondary (fluorescent)...