Wavelength Tech Forum: FT-IR/NIR Spectroscopy

Sep 10, 2007
By Spectroscopy Editors

This month’s Technology Forum looks at the topic of FT-IR/NIR spectroscopy and the trends and issues surrounding it. Joining us for this discussion are Rohit Bhargava , with the University of Illinois, Chris Petty, with Thermo Fisher Scientific, Jim Yano and John Beauchaine , with Aspectrics, Richard Larsen, with Jasco, Inc., and Alan Rein , with A2 Technologies.

What kind of impact do you see FT-IR/NIR having in the biofuels market?

(Bhargava) Tremendous. Spectroscopic techniques will be needed for characterization of raw materials, in process settings and for final validation. FT-IR/NIR offers an attractive blend of information, cost, relatively straightforward instrumentation and familiarity for many users. This will be an area of intense activity in the coming years.

(Petty) We are already seeing significant use of spectroscopy technologies in the biofuels market. Several different techniques are being used and each has its place in the production and distribution chain of that emerging industry. In my experience most techniques are available in the labs of the researchers and this is where much of our early experience has come. Now that the industry is scaling up in a number of areas, we are seeing more targeted use of the systems where they add the most value. For NIR we generally see most interest in making on-line or at-line process measurements in the production of the bio materials. In the QC labs much of the work is still done with standardized wet chemical tests or chromatography but FT-IR really adds a lot of value in the blending stage. FT-IR gives a fast, cost effective method for analysis of biodiesel (FAME content) and our analysis system is already in use both by producers and the industry regulatory bodies. As we go forward, I expect the use of instrumentation in all parts of the biofuels process to increase substantially – it is an environment sensitive to productivity and people are starting new facilities with their measurements and monitoring designed in.

(Yano/Beauchaine) Mid Infrared FT-based systems have been used for some time in the at-line environment for biofuels. It appears that the next growth areas for biofuels are in the on-line and field portable segments. Mid-IR FT technology is well established for the at line segment but not easily integrated into the on-line environment. EP-NIR on the other hand was designed to address the on-line challenges as well as field portable segment. As biofuels continue to supplement our gasoline and diesel demand we will begin to see more focus on the quality of the biofuels as well as remote field monitoring and troubleshooting. We see the field portable market expanding to address concerns of the fleet operators over the blend ratio value (“B” value) for biodiesel.

(Larsen) FT-IR analysis methods have already been implemented in several ways for biofuels. As documented procedures are written by regulatory agencies (e.g., DOE, ASTM, EPA, etc.), I believe that FT-IR/NIR will continue to become one of the primary analysis techniques for the control of biofuel quality and production.

(Rein) Both FT-IR and NIR can have a significant impact in analyzing and monitoring biofuel production. With the reduction in size, complexity and concurrent increases in ease-of-use and portability/mobility of infrared spectrometers, coupled with pricing that is equivalent to or less than chromatography and wet chemical analyzers, infrared spectrometers are well positioned to be viable tools for biofuel analysis.

What are your thoughts on the role of FT-IR/NIR in Homeland Security?

(Bhargava) FT-IR/NIR have a role to play in forensics that is well established. Imaging versions of FT-IR/NIR technologies are likely to play a bigger role going forward. At the same time, they will need to be integrated with expert data analysis systems. Hence, integrated solutions comprising spectrometers, chemometrics/databases and specialized accessories are likely to be useful.

(Petty) FT-IR has played a strong part in homeland security. Molecular spectroscopy has always provided a fast accurate way to identify unknown materials or at least quickly screen unknowns for "high risk" possibilities – this is of paramount importance in homeland security. At this point, there are a number of different technologies that have applicability to this problem. FT-IR in a “luggable” format was there early and therefore has seen some success but now people are considering truly hand-held Raman or NIR systems as viable alternatives.

(Yano/Beauchaine) FT technology as well as EP-IR technology will continue to make advances in the near real time screening application space. Unlike chromatography, spectroscopy-based systems can provide results without the need to perform lengthy sample preparation or separation. The result is a near real-time monitoring device that can trigger an alarm within seconds in the detection of a lethal agent.

(Larsen) FT-IR, like Raman spectroscopy, is one of the few analytical methods that can provide positive identification of chemical substances, thus, offers a great deal of capability for homeland security measures. I think that this has been aptly demonstrated by the manufacturers of portable FT-IR instruments. While there are other chemical identification techniques available, none are as portable or as flexible as FT-IR, which can measure gases, liquids and powders. With the continual growth of digital spectral libraries being compiled by vendors and users, FT-IR offers a powerful method for the identification of hazardous materials.

(Rein) FT-IR has already had significant impact in Homeland Security. The future of FT-IR in Homeland Defense will see systems become smaller, more affordable and with powerful software and algorithms to elucidate the components in mixtures even more effectively.

What is on the horizon for Encoded Photometric Infrared (EP-IR)?

(Bhargava) This is an exciting technique and is likely to be useful for process or field applications. The company was started by experts in optics and they have recently built strength with personnel from the spectroscopy community. I would suppose that they will plan to integrate their spectrometer with many accessories useful for practitioners, e.g. ATR, microsampling etc.

(Petty) EP-IR hasn’t yet set the world on fire! The technology is novel and some early adopters showed interesting results when it began being publicized a few years back. At least from my perspective, it isn’t clear yet that the benefits outweigh the compromises in a wide range of applications. This is an interesting time in an interesting field – there are many, many new technologies being promoted every year and EP-IR is one of them. When these things get really exciting to me is when they start moving beyond the early lab tests and are being used in large volumes for real world problems. It would be impossible to say at this point whether EP-IR can make that leap!

(Yano/Beauchaine) Because of the rugged design and the compact footprint, we see EP-IR and EP-NIR being deployed into remote field applications and process applications. In addition, because the platform is web enabled we feel that the technology will receive rapid acceptance in these two key application areas. Furthermore, the rapid scanning (100 scans/second) capability of the EP-IR/NIR is ideally suited for reaction monitoring applications associated with bioreactors and fermentation processes. Unlike HPLC-based systems, the EP-IR/NIR can provide real time results without the need for sample preparation or separation.

(Larsen) I am not that familiar with this particular class of instruments, but do feel that the speed of these instruments will provide some capabilities not currently offered by low-cost FT-IR instruments. My concern is the sensitivity of these instruments and lack of flexibility for various analysis methods.

What has been the biggest advancement in FT-IR/NIR in the past few years?

(Bhargava) Without a doubt, the biggest story has been the evolution of imaging. Starting from a few specialized laboratories, many academic, industrial and government agencies have invested in this technology. Imaging has driven the need for advanced numerical processing and visualization of data. It has also enabled new applications, for example, in analyzing tablets or in automated histopathology.

(Petty) I would have to say the commercialization of spectroscopic imaging systems and the software to make sense of the measurements. The technology for acquiring the data is moving fast and costs are coming down in many areas. A lot has been written already about the hardware so I would like to highlight some of the software marvels in this space. This is a technology that has moved past the "early adopter" stage where a beautiful image was an end in itself – now we are in an environment where getting usable information from the measurements is the system's justification. This is in the software. The ability to pull quantitative information on concentrations, particle sizes, and laminate thicknesses or to visualize these analyses in ways that are immediately useful, all with a few mouse clicks is incredible when you consider the amount of data being generated.

(Yano/Beauchaine) The primary advances have been in ease-of-use software that is more targeted at producing accurate numbers rather than traditional spectroscopy interfaces which were more targeted for the researcher. One of the most powerful features of NIR analysis has been in sampling. Sampling is less complex due to the fact that longer pathlengths can be used in the NIR. Also, fiber optics allow for safe transportation of the NIR light to the process line.

(Larsen) The continued decrease in size of the instruments as well as the decreased cost of ownership has, in my estimation, been the most drastic advancement in FT-IR/NIR.

(Rein) The biggest advancement in FT-IR instrumentation has been the development of far more compact and rugged optics/electronics that enable systems to be designed for use in out-of-lab applications. The single most important sampling development in the last ten years was the development and commercialization of the diamond ATR interface. Diamond ATR technology is now used in tens of thousands of applications, worldwide.

What improvements do you think could be made to the FT-IR/NIR systems?

(Bhargava) We have excellent technology for most applications. User-friendliness is, however, generally lacking. Some of this stems from using old electronics and software that does not take advantage of modern operating systems in PCs. We are seeing product refreshes that greatly improve the operability and stability of instruments while making them easier to use.

(Petty) Simplification. Everyone talks about ease-of-use (to the point where it is a cliché) but the truth is for many systems, you still need a significant amount of expertise to get good measurements and to get useful information from your measurements. Real simplification is when the system does a lot more to make sure you are getting good information and lets the experts focus on their work more or less on the instrument. Ultimately this will bring more instrumentation into the hands of people who wouldn’t consider using it today and at the same time, make the spectroscopy gurus more productive. More quality control, more troubleshooting closer to the point where problems are happening and we are all better off.

(Yano/Beauchaine) Easier to integrate into the process environment, more rugged and occupy a smaller footprint.

(Larsen) I’m not sure what additional improvements could be made to FT-IR instruments. Increased signal-to-noise capability, lower cost of accessories such as FT-IR microscopes, decreases in cost for research grade instruments all come to mind, but these changes will probably be adopted gradually.

(Rein) The greatest improvements will be in the area of software, chemometrics and algorithm development. These enhancements will enable infrared to be more useful in elucidating complex mixtures and enhancing the ability to detect lower levels of analytes. The overall systems will continue the trend of smaller, less expensive tools for out-of-lab applications.

What do you think?

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