Fourier Transform Infrared Spectroscopy (FTIR)

Infrared spectrometry is useful for the identification of both organic and inorganic compounds. Aggregates of atoms (or functional groups) such as C=O, -NO2, C-N, and C-F; just to name a few, are all associated with characteristic infrared absorptions. Thus, infrared spectrometry is ideal for the identification of functional groups present within a sample. FT-IR capabilities within the MCL are geared towards the analysis of solids (organic, inorganic, and biological) in a variety of forms to include: fibers, thin films, microtome cuts, particles, powders, coatings, residues, monolayers, and monolithic solids. With the recent acquisition of an infrared microscope MCL now has FT-IR mapping/imaging capabilities along with the capacity to perform infrared microanalysis on samples down to ~10 microns in size.

Sample Requirements

• The detection limit for routine analysis is ~0.1 wt%; under ideal conditions greater sensitivity can be achieved.
• Typically only a few milligrams of material are needed for analysis.
• Samples may be in liquid, solid, or gaseous form. MCL has a signifcant collection of sampling accessories. See below.
• Additional sample requirements vary widely depending upon the specific technique employed for analysis.

FTIR Instrumentation
Bruker IFS 66/S and Bruker Vertex V70

The IFS 66/S and V70 are high performance research grade FT-IR spectrometer equipped with a wide range of sampling accessories. Through the use of interchangeable optical components MCL has the ability to acquire data over the near-IR (12,000-4,000 cm-1), mid-IR (4,000-400 cm-1), and far-IR (680-30 cm-1) regions. Additionally, the IFS 66/S is a step-scan capable instrument for high temporal resolution spectrometry.

Bruker Hyperion 3000 Microscope

The Hyperion 3000 FT-IR microscope enables the acquisition of mid-IR and near-IR spectra from very small (>10 µm) samples with diffraction limited spatial resolution. Various collection modes are available and include: transmission, specular reflectance, attenuated total reflectance, and reflection-absorption. The microscope is equipped with brightfield, darkfield, and fluorescence illumination as well as polarization capabilities to enhance contrast and facilitate sample visualization. In addition to single point measurements, the microscope possesses extensive mapping and imaging capabilities. Use of the single element MCT detector in conjunction with the computer controlled stage permits sample mapping with a positioning accuracy of ±3 µm . The 128 x 128 element focal plane array detector enables diffraction limited mid-IR imaging of areas as large as 340 x 340 µm.

Sampling Accessories

Transmission

• FT-IR microscopy, 15x and 20x objectives (w/polarizer)
• Brewster’s Angle Holder (w/polarizer)
• Liquid Cell (many spacers/windows)
• Diamond Compression Cell
• Pellet Press (7mm die set)
• Gas Sampling Cell

Specular Reflectance

• FT-IR microscopy, 15x and 20x objectives (w/polarizer)
• FT-IR microscopy, 15x grazing angle objective (w/polarizer)
• Pike VeeMax II (variable angle/polarization)

Attenuated Total Reflectance

• FT-IR microscopy, 20x objective – Ge crystal
• Pike HATR, horizontal multiple reflection (liquid trough)
• Harrick MVP Pro Star, single reflection (diamond crystal)
• Pike VeeMax II (variable angle & polarization)
• Harrick GATR, grazing angle (w/polarizer)

Diffuse Reflectance

• Harrick Praying Mantis (ambient, air-tight, and high temperature reaction cell)
• Spectra Tech, Collector II (ambient, high temperature reaction cell)

Other

• MTEC Model 300 Photoacoustic