Fourier Transform Infrared (FTIR) Spectroscopy

Fourier Transform Infrared (FTIR) Spectroscopy is used to perform qualitative and quantitative analysis of organic compounds and to determines the chemical structure of many inorganic compounds. The FTIR microscope accessory permits analysis of samples as small as a few microns in diameter.  Shown is the new Agilent Cary 670 FTIR with the Cary 610 FTIR microscope recently acquired by PhotoMetrics.

Applications: FTIR analysis applications include:

  • Materials evaluation and identification
  • Organic compounds
  • Structure of many inorganic compounds
  • Deformulations
  • Forensics
  • Material homogeneity
  • Failure analysis
  • Micro-contamination identification
  • Adhesive performance
  • Material delamination
  • Corrosion chemistry
  • Quality-control screening
  • “Good-to-bad” sample comparison
  • Evaluation of cleaning procedure effectiveness
  • Comparison of materials from different lots or vendors

Principle of Operation Because chemical bonds absorb infrared (IR) energy at specific frequencies (wavelengths), the basic structure of compounds can be determined by the spectral locations of their IR absorptions. The plot of a compound’s IR transmission versus frequency is its “fingerprint,” which when compared to reference spectra identifies the material.  PhotoMetrics maintains one of the largest commercial IR-spectrum libraries and offers a spectral search service to its industrial clients and other laboratories for identifying the materials in the spectra obtained. FTIR spectrometers offer speed and sensitivity that was impossible to achieve with earlier wavelength-dispersive instruments. This capability allows rapid analysis of micro samples down to the nanogram level in some cases, making the FTIR unmatched as a problem-solving tool in organic analysis. The FTIR microscope accessory allows spectra from a few nanograms of material to be obtained quickly, with little sample preparation, resulting in more data at lower cost. In some cases, thin films of residue are identified with a sensitivity that rivals or even exceeds surface analysis techniques based on electron or ion beams. As an analytical technique, FTIR has few sample constraints.  Solids, liquids and gases can be accommodated. In addition, many contaminants present on reflective surfaces, such as solder pads or printed circuitry, are readily analyzed in situ using the FTIR microscope in reflectance mode.