Raman Vs FTIR Flashcards
What does Raman spectroscopy use to analyze substances?
A laser to measure molecular vibrations via scattered light.
What type of scattering does Raman measure?
Inelastic scattering (Raman scattering).
Fill in the blank: Raman spectroscopy works by analyzing the energy shift of _________ photons caused by molecular vibrations.
scattered
What is the typical laser wavelength used in the ACE-ID?
785 nm
What does ORS technology in ACE-ID do?
Spreads laser energy across the sample surface to avoid heating and improve signal clarity.
Fill in the blank: The detector in Raman spectroscopy measures the __________ spectrum, which is a molecular fingerprint.
Raman
What is Raman spectroscopy best at detecting?
Non-polar molecules and carbon-based compounds.
What is the purpose of a notch or edge filter in Raman spectroscopy?
To remove Rayleigh scattering and isolate Raman scattering.
Fill in the blank: Raman spectroscopy generates a spectrum that shows __________ intensity as a function of __________.
scattering; wavenumber
What type of sample preparation is needed for Raman spectroscopy?
None. It can analyze substances without preparation.
What kinds of materials can Raman struggle with?
Fluorescent or dark materials (they interfere with the laser signal).
What detector is used in the ACE-ID for Raman scattering?
A CCD detector (Charge-Coupled Device).
Fill in the blank: Raman spectroscopy is based on light interacting with the __________ of a molecule.
vibrations
Why is Raman suitable for hazmat scenarios?
It allows for non-contact analysis through clear containers, reducing exposure.
Why is the ACE-ID safer for explosive materials?
It uses Orbital Raster Scan (ORS) to reduce laser heating on the sample.
What does FTIR stand for?
Fourier Transform Infrared Spectroscopy.
What kind of light does FTIR use?
Infrared light from a broad-spectrum source.
What does FTIR measure?
The absorption of infrared light by molecular bonds.
Fill in the blank: FTIR uses a __________ to split and recombine IR beams, creating an interference pattern.
Michelson interferometer
What is the primary material used for the ATR crystal in the HazMatID Elite?
Diamond.
What type of molecular bonds is FTIR best at detecting?
Polar bonds (e.g., O-H, C=O).
Fill in the blank: The ATR crystal creates an __________ wave that penetrates the sample to analyze its molecular vibrations.
evanescent
What does the interferometer in FTIR do?
It splits the IR beam into two paths and recombines them to create an interference pattern.
What is the role of the Fourier Transform in FTIR?
Converts the interference pattern into a usable IR spectrum.