AAS (Atomic Absorption Spectrometry)
Definition
An analytical technique measuring the absorption of element-specific wavelengths by atomised sample. For GSR, it quantifies dissolved Pb, Ba and Sb in hand-wash or HNO3 swab extracts. Cannot confirm particle co-localisation; has lower specificity than SEM-EDS.
- Measures
- Lead, barium, antimony (GSR elements)
- Principle
- Element-specific wavelength absorption
- Sample source
- Hand-wash or nitric acid swab extract
- Limitation
- Cannot confirm particle co-localisation
Common questions
How does AAS compare to SEM-EDS for GSR analysis?+
AAS gives a bulk elemental concentration from a dissolved sample and has no way to show particle shape. SEM-EDS instead images and analyses individual particles, so it can confirm the fused, spherical morphology that is more specific to true GSR.
Why can't an AAS lead-barium-antimony result stand alone as GSR confirmation?+
Environmental and occupational sources can also deposit those same elements on hands. Without particle morphology data, an elevated bulk reading is consistent with GSR but does not exclude other sources on its own.
Related terms
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