Traditional Uses Giving Way to Portability, Microscopy
Although serious Fourier-transform infrared spectroscopy (FTIR) research and core analysis facilities are still alive and well, traditional applications are giving way to more dynamic uses such as controlling processes and field work.
For research FTIR, where polymer, materials, coatings, and industrial applications still predominate, the new kid on the block is cell and tissue analysis. Modern biology relies heavily on fluorescently labeled dyes that identify cells’ surface markers and internal workings. Cells are then isolated and characterized by cell sorters according to which labels light up. Tissues are similarly analyzed by fluorescence microscopy.
But microscope-based imaging FTIR, says Keith Bratchford, marketing director at Agilent Technologies’ Melbourne, Australia, facility, is making inroads into cell biology in ways that were barely imagined just a few years ago.
Using this technique, scientists can create multidimensional maps of a tissue based on its chemical composition. The technique has numerous applications in the diagnosis of abnormal cells and tissues in a variety of diseases, including cancer, Alzheimer’s disease, and Parkinson’s disease. The enabling technology behind this is the focal plane array detector, which rapidly provides a full spectrum for every pixel within the microscope field in a matter of seconds. Performing the same analysis with single-point detectors could take many hours or days and not provide the same level of resolution.
“Focal plane arrays acquire all spectra at once, the same as taking a photograph with a CCD-based camera. The arrays capture significant areas of the sample in one shot,” says Mr. Bratchford, “but you need a lot of very highlevel processing to handle the data.”
When fully developed, FTIR microscopy will have numerous applications in food safety and pathogen detection. Agilent is working with McGill University in Montreal on techniques to identify bacteria rapidly. One day, spectral libraries of viruses, bacteria, and fungi will allow rapid screening of medical, pharmaceutical, and food products for pathogens. “FTIR could significantly reduce the number of samples coming back to the lab for culturing,” Mr. Bratchford tells Lab Manager Magazine.
Dealing with “de-skilling”
A key trend in FTIR instrumentation, according to Sharon Palmer, materials characterization business manager at PerkinElmer (Bucks, UK), is the “deskilling” of the user base. Many labs, she says, used to maintain dedicated FTIR resources that included laboratory- trained, degreed scientists. Now instrument operators have multiple responsibilities and may not have the same level of expertise with any one of them as did their predecessors.
Related is the issue of transportability. No, we’re not talking handheld FTIR, but rather instruments that may be moved from one location within the facility to another: taking the analysis, as Ms. Palmer puts it, “to the point of pain.”
“Rather than bringing the sample to the instrument, bring the instrument to the sample.”
Earlier this year, PerkinElmer relaunched its entire FTIR spectrometer line to emphasize transportability, particularly in nontraditional “lab” environments. In a frank departure from conventional lab FTIR instrument designs, transportable devices must be insensitive to vibration and changes in humidity.
One such instrument, the Spectrum Two, weighs in at about 26 pounds. While hardly pocket-sized, it can easily be wheeled around on a cart. And yes, it’s battery powered.
PerkinElmer has long been a proponent of simplifying software as well. FTIR products are controlled through an application iPhone users would appreciate. Users are provided with a very limited number of choices on each screen but at the same time may access detailed guidance and instructions.
Ms. Palmer sees FTIR becoming more useful in screening applications due to its ease of use and the growing need to obtain answers quickly. In addition to the microbiology applications mentioned earlier, Palmer anticipates methods for screening food and pharmaceutical ingredients, adulterated fuels, raw materials, and counterfeit drugs. “There are many potential opportunities where FTIR offers one or more pieces in the puzzle.”
Tim Rider, sales manager at Bruker Optics (Billerica, MA), puts the evolution of FTIR into a usability perspective: “Twenty-five years ago it took an expert to run FTIR. Now you can put instrumentation in places where IR has never been used before.”
The Rodney Dangerfield of instrumentation?
FTIR is the workhorse technique at Chemir (Maryland Heights, MO), a “problem solving” analytical lab. The “ir” in the company’s name stands for infrared.
“We use FTIR on more than half the samples that come through the door,” says Tim Janota, senior analytical chemist. Chemir tackles such problems as deformulating fingernail polish, determining the cause of foul odors in seafood, characterizing naval munitions propellants, and identifying contaminants in footwear. Projects involving intellectual property, liability, insurance coverage, and potential litigation are its specialties.
By the time you read this, Chemir will have upgraded its Thermo Nicolet IS- 10 FTIR to a new 6700 model instrument, also from Thermo (Waltham, MA). Mr. Janota has a bias toward the Nicolet brands because of the instruments’ sampling accessories. The new system also has near-IR capability.
Chemir’s spectral library will also receive an upgrade, from 50,000 spectra to 70,000. Libraries have improved to the point, Mr. Janota says, where functional group analysis by searching for bands has become passé. “Now you just look for a library match, except in cases where you have a mixture or a poor spectral confirmation.”
Despite FTIR’s renaissance, particularly with microscopy methods, Mr. Janota feels that infrared is seriously underutilized in analytical labs. “People have these new gas and liquid chromatographs, with mass detection, with all the bells and whistles. That’s what they’re familiar with, so that’s how they solve their problems. But there’s still a lot of information you can get using FTIR. One wonders if this is a reflection of how today’s scientists are trained.”
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