Fourier transform infrared (FTIR) spectroscopy, a subset of infrared (IR) spectroscopy, uses a mathematical algorithm, Fourier transform, to translate raw infrared data into a spectrum.
Like IR, FTIR is useful for the analysis of organic and inorganic compounds that exhibit changes in polarity as a result of the vibration, spinning, or perturbation of molecular bonds. FTIR methods are common in such industries as foods, materials, chemicals, pharmaceuticals, forensics, and others. Advantages of FTIR over conventional IR are higher resolution, better signal-to-noise, easier analysis of very small samples and poorly-absorbing species, and much more rapid analysis.
“There’s a lot of pressure to bring FTIR out of the lab and into the field,” said Haydar Kustu, global marketing communications manager at Bruker Optics (Billerica, MA). One of the most exciting scientific advances in this regard are MEMS (microelectromechanical systems), which enable rugged, low-cost handheld devices. “MEMS shrink the interferometer,” Kustu adds. Another enabling technology has been quantum cascade lasers (QCLs), which are brighter and more sensitive than conventional lasers. “MEMS and QCLs will open up many more niche or field applications for FTIR.”
Unlike laboratory instruments, field analyzers are typically dedicated for single analytes. “These are built for specific purposes. You cannot swap out accessories, change from transmission to reflectance, or change the detector or the source. You cannot configure them on the go,” says Kustu.
The proliferation of FTIR into materials, fuels, biology, environmental testing, and homeland security raises issues of usability and user-friendliness that did not exist a decade ago. “Users today are more likely to be non-specialists or occasional users than IR spectroscopists,” says Jerry Sellors, Ph.D., manager for FTIR at PerkinElmer (Beaconsfield, UK). In this environment, instrument makers must emphasize user-friendliness for both hardware and software. “Users today are less interested in buying an FTIR spectrophotometer than they are in acquiring a biodiesel or contaminant analyzer. Purchase decisions are influenced more by how well an instrument performs a specific task than by its technical specifications.”
Cost and the performance/price ratio remain factors, perhaps more so due to the economic downturn, but remain unchanged in nature over the past two decades. Another factor that still matters very much is the perception of how well vendors support their products, both around the sale and afterward. In this regard, Sellors suggests that global communication within and among companies helps spread the word about which instrument manufacturers make the cut.
“In addition to budget issues, purchasers need to be clear, before they buy an FTIR spectrometer, on their applications,” advises Dr. Smith. “It’s too easy to get taken in by the ‘gee whiz’ factor. Most vendors offer quality instruments; the difference for the average user may be the software. It’s imperative to take the software for a test drive, and not just let the salesman show you how it works. Take a spectrum yourself before you buy, and get references [from people] who can vouch for the manufacturer’s service.”
• Can be operated without any scheduled maintenance for ten years
• Features a simple and robust interface for data acquisition and routine analysis
• Universal sampling compartment accommodates accessories like liquid vial holders and probes
• Includes a user-friendly software interface enabling operations in a 21 CFR Part 11-compliant mode
• Dynamic Alignment system maintains optimal alignment during data acquisition
• Features a peak-to-peak signal-to-noise ratio of 20,000:1
• Quick-start function prompts user through every action from setting scan parameters and acquiring spectrum to detecting peaks and printing
Shimadzu Scientific Instruments
ML with DialPath™ Technology
• Three selectable pathlengths from 30 to 250 microns are always available and can be switched in seconds
• Eliminates traditional liquids cells which are prone to leaking, fringing and breakage
• Entire system fits on a benchtop in a space no greater than 8 square inches
• Measures liquid samples so quickly that autosamplers may be eliminated
Exoscan and FlexScan
• Battery-operated, handheld spectrometers for field applications
• Identify minerals and soil components and quantify molecular compounds including oil contamination or degree of hydration in soil
• Feature a diffuse reflectance sampling interface
Like this article? Click here to subscribe to free newsletters from Lab Manager