ABOUT THE INSTRUMENTATION

Fourier Transform Infrared Spectroscopy (FTIR) is a spectroscopic technique used for the identification of most organic and many inorganic compounds.

When a material is placed in a beam of IR 'light', some of this energy will be absorbed by the material and not transmitted through the material. In the resulting FTIR spectra, deflections (“IR absorbance bands”) from the baseline indicate the frequency region of 'light' absorbed and can be assigned to specific groupings of atoms; e.g., C-H, C=O.

In many cases, identification of a material can be made based on the presence of a number of these bands. The availability of reference spectra of known compounds increases the probability of making a positive identification.

FTIR's ability to unambiguously identify a compound decreases with the complexity of the chemical structure and the number of components in a mixture of compounds.

For certain chemical compounds, FTIR is a very sensitive quantitative analytical method and can detect materials present with concentrations of single digit ppm's.

Instrumentation:

Thermo Scientific Nicolet iS10 FTIR Spectrometer

Smart iTR ATR sampling accessory with diamond and germanium crystals

Nicolet Magna 550 FTIR Spectrometer

Sampling Accessories: Salt plates, solution cells, ATR, DRIFTS, specular reflection, grazing angle specular reflection, short path length gas cell

Nic-Plan IR Microscope

Sampling Accessories: Micro Diamond Anvil for transmission, Micro-ATR and Micro-reflectance

Reference Library of 75,000+ spectra


Please click to learn more about FTIR, the Nicolet FTIR Spectrometers and NicPlan IR Microscope and find examples of how the FTIR can be used.

ADDITIONAL INFORMATION

The Thermo Scientific Nicolet iS10 FT-IR Spectrometer is Thermo's most recent compact and stable interferometer design optimized for the mid-IR region (4000-400 cm-¹). The Smart iTR attenuated total reflectance (ATR) sampling accessory, with both diamond and germanium crystals, has extremely high light throughput which allows the timely acquisition of high signal-to-noise IR spectra from a wide variety of difficult sample types with little preparation. Automatic system performance verification is done with ASTM validation protocols and NIST certified standards to ensure consistently high performance and instrument qualification for quality audits.

The Nicolet Magna 550 is also used for the identification of organic and inorganic materials having absorbance bands in the mid-IR spectral range (4000-400 cm-¹).

The main bench is used for recording IR spectra of a wide variety of sample types, solids, liquids, gases, articles of commerce, using a variety of sampling accessories:

• Transmission spectra of unsupported and supported thin films
  
• Transmission spectra of thin liquid films between salt plates
  
• Transmission spectra of dilute solutions in fixed and variable pathlength cells
  
• Transmission spectra of gases in a 10 cm short pathlength cell
  
• Attenuated total reflectance (ATR) spectra of solid surfaces and liquids using 45^o/60^o Ge, KRS-5 and ZnSe crystals in vertical and horizontal orientations
  
• Diffuse reflectance spectra ('DRIFTS') of powders
  
• Specular reflectance spectra of reflective materials
  
• Grazing angle specular reflectance spectra of ultra-thin layers on flat reflective surfaces and trace residues on gold coated microscope slides.

FTIR has the sensitivity to detect monolayer thicknesses of materials on reflective substrates and single-digit ppm levels of analytes in solution.

The Nic-Plan IR Microscope is an excellent sampling method for many types of samples that allows the acquisition of IR spectra not able to be obtained by any other technique. The IR Microscope has its own dedicated liquid nitrogen cooled MCT-A detector and covers a spectral range for 4000-650 cm-¹.

The IR Microscope has several sampling options:

• Transmission spectra of samples formed as optically thin films on a diamond anvil cell.
  
• Reflectance spectra of optically thin films on a reflective substrate
  
• Attenuated total reflectance (ATR) spectra of solid surfaces and liquids using Ge and ZnSe micro ATR crystals.

The most useful feature of this microscope methodology is the capability to analyze small samples. The practical minimum spatial resolution for transmission and reflectance spectra is ca. 20-25 µm. With certain samples and conditions, better spatial resolution can be obtained. The practical ATR 'analysis spot' size is 50-100 µm depending upon the sample.

The analyst is aided in the identification of unknown materials by an on-site library of reference spectra in excess of searchable 75,000+ spectra with access to online commercial spectral databases. In most cases, the analyst must rely on his/her expertise to develop an accurate interpretation of the IR spectrum.

This versatile instrumentation can be used for analyses of many different materials and products used in a wide range of applications; including the following:
Deformulation of complex industrial and consumer specialty chemical products
Identification of unknown organic and inorganic materials

Identification of contaminants in-process and finished parts

Forms basis of QC methods to accept raw materials, finished goods and monitor chemical processes

Determine the extent of a chemical reaction and identify reaction products

Characterize chemical surface modifications of polymers and powders
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Help locate the locus of failure in adhesive bond failure

Identify fibers

Identify individual layers in co-extruded and multilayer polymer film constructions

Identify lubricants on metal surfaces

Quantify the level of the level of curing agents in epoxy coating solution