Attenuated Total Reflectance (ATR) FTIR
Definition
An infrared spectroscopy configuration where the IR beam passes through an ATR crystal and generates an evanescent wave that samples a thin surface layer of the pressed sample. Enables direct contact measurement of solid and liquid explosives and precursors.
- Full name
- Attenuated total reflectance FTIR
- Mechanism
- Evanescent wave from an ATR crystal samples a thin surface layer
- Sample types
- Solid and liquid explosives and precursors
- Sample handling
- Direct contact, no extraction needed
Common questions
Why is direct-contact ATR-FTIR well suited to field explosives screening?+
It needs only a small amount of sample pressed against the crystal and produces a spectrum within seconds without dissolving, extracting, or otherwise consuming the material, which matters when the sample is limited, potentially hazardous, or needed intact for later confirmatory lab work.
What distinguishes this technique from Raman spectroscopy in explosives detection?+
ATR-FTIR requires physical contact between the crystal and the sample and probes vibrational modes through infrared absorption, while Raman is typically non-contact and can work through some packaging. The two are often used as complementary confirmatory methods because they respond differently to certain compounds and interferents.
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