XRF and ICP-MS
Definition
Elemental techniques for the trace-metal fingerprint (Fe, Ti, Mn, Cr, Ni, V, rare earths). XRF (often EDXRF) is non-destructive; ICP-MS is destructive but reaches sub-ppb sensitivity. Both are routine in CFSL trace divisions.
- Target signal
- Trace-metal fingerprint (Fe, Ti, Mn, Cr, Ni, V, rare earths)
- XRF
- Non-destructive, EDXRF common
- ICP-MS
- Destructive, sub-ppb sensitivity
- Use setting
- Routine in CFSL trace divisions
Common questions
Why run both XRF and ICP-MS on the same sample instead of just one?+
XRF is fast and non-destructive so it can screen a sample first without consuming it, while ICP-MS destroys the sample by dissolving it but reaches far lower detection limits, so a common workflow screens with XRF and reserves ICP-MS for confirmatory or trace-level questions.
What does sub-ppb sensitivity mean in practical terms for trace evidence?+
It means ICP-MS can detect metal concentrations at parts-per-billion levels, orders of magnitude below what XRF can typically resolve, which matters when the trace-metal fingerprint distinguishing two soil or dust samples lies in elements present only at very low concentrations.
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