In a fatal hit-and-run, grey paint smears are lifted from the victim's clothing. Stereomicroscopy shows four paint layers matching the suspect vehicle's repainted fender. Which analytical technique BEST discriminated the binder chemistry of the paint chips?

• A Neutron activation analysis
• B Scanning electron microscopy of surface topography
• C Thin layer chromatography of extracted pigments
• D Pyrolysis gas chromatography-mass spectrometry ✓

Explanation

Pyrolysis GC-MS thermally decomposes the paint binder and separates the volatile fragments, giving a fingerprint of the resin system that distinguishes chemically similar paints even when colour and layer count match. Neutron activation analysis targets elemental profiles, not binders. TLC of pigments adds little beyond colour comparison. SEM describes morphology and elemental surface content but does not characterise the organic binder.

Reference: Saferstein, Criminalistics: An Introduction to Forensic Science, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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