Molecular Spectroscopy Gets Handier

Portability has long been touted as a powerful capability of molecular spectroscopy systems, and in the last couple of years portable molecular spectroscopy has gained momentum, especially with the introduction of portable Raman systems. In fact, a number of new products have recently been introduced to the market (see IBO 3/15/08). Among the advantages of portable spectrometers, which also include NIR, FT-IR and UV-Vis systems, are that they are generally less expensive, enable field testing and can save time previously used for the transport of field samples to a lab. Some portable systems are personal handheld devices, while others are designed for stationary use and can be easily carried from one location to another. Increased user friendliness, technological development and new applications are all contributing to the market’s growth. Advances in technology such as cheaper, smaller and more powerful light sources and detectors, more efficient optical components, as well as drastically improved battery life and power usage have helped the technology to mature. Newer systems are also more user-friendly in instrument control, data display, weight, size and interface. Perhaps the most indicative sign of momentum is the development of new applications for portable systems, including those for nonscientists.

Ahura Scientific’s systems are an example of the rapid adoption of portable spectroscopy. The company has shipped over 2,000 systems since its first product was introduced in 2006. Ahura offers three handheld spectroscopy systems. The four-pound TruScan and FirstDefender portable Raman systems, both introduced in 2006, are for industrial and security applications, respectively. Introduced in January 2008, the TruDefender FT is a portable FT-IR system weighing less than three pounds that complements the FirstDefender for security applications. All three systems are designed for both nonexpert and expert use. Ahura attributes the success of its handheld instruments to multiple factors. System packaging is compact and conforms to MIL-STD 810F standards, the US military’s second-highest standard for ruggedness in the field. In addition, the software used by all three devices can identify a sample in less than a minute.

Doug Kahn, chairman and CEO of Ahura Scientific, told IBO that although many advancements had been made in the field of portable spectroscopy when the company was developing its first system, Ahura had to develop its own parts, including its own semiconductor chip and laser, in order to create a Raman system rugged and accurate enough for use in the field. He made it clear that to be able to attain the company’s goal of reaching nonscientists, technological advances took a back seat to creating a simple user interface. “To have winning products in the market, it is not about meeting technical challenges, it is about meeting a new class of customer and meeting that customer’s needs, which are much broader and much different from a PhD in a lab.” This ability to attract customers who have never used the technology has opened the door for new applications for both portable FT-IR and Raman.

According to Mr. Kahn, new applications for the company’s instruments are abundant; for example, testing shipments of raw materials for pharmaceutical manufacturing. Rather than testing an FDA-mandated portion of incoming materials, the whole batch can be tested. “Now that our technology is available, they can scan the barrels right when they arrive on the loading dock. The people who are assigned the responsibility of validating these materials can be the loading-dock workers [rather than researchers at a quality assurance lab], because they have a handheld device that has a green screen or a red screen to signal correct material and incorrect material,” he said. “The FDA is encouraging pharmaceutical companies to move away from statistical sampling to 100% sampling of raw materials, because far less costly personnel is used,” he explained. With regard to applications in hazardous materials analysis, the quick readings from a portable Raman or FT-IR spectrometer can be used to establish the identity of an unknown substance on the spot, eliminating the need for quarantining a location and cutting the time that personnel are in hazardous situations. As for other potential drivers of the market, Mr. Kahn cited cost savings. Companies can purchase portable instruments to be run by non-experienced personnel, instead of using lab systems that must be operated by scientists.

Unlike Ahura, Analytical Spectral Devices (ASD) has been providing portable NIR systems for niche applications since 1990 with the skilled user in mind. While the company does provide a line of portable general-purpose NIR analyzers as well as laboratory systems, it has experienced the most growth due to its portable application-specific analyzers. When describing the power and accuracy of the portable systems, Dr. Brian Curtiss, co-founder and CTO of ASD, said, “ASD’s line of QualitySpec benchtop systems use the same spectrometer engine as ASD’s portable units.”

The company manufactures dedicated portable NIR systems for agricultural, mineralogical and paper testing, among other applications. However, the RxSpec 700Z, released in May 2008, which is specifically designed for counterfeit-drug detection, is ASD’s first portable NIR system for unskilled as well as skilled end-users.

The company’s focus on developing products for specific markets is due to NIR’s requirement for extensive calibration, which also leads to a close relationship with end-users. “We have found that many of the end-users who have a need for portable instrumentation do not have the staff or facilities necessary to develop and maintain NIR calibrations,” explained Dr. Curtiss. “Much of our success has been achieved by providing a complete package that includes not only application-specific instrumentation, but also the calibration and support necessary to maintain both the hardware and the calibration,” he added. This experience with developing portable instruments tailored to specific applications due to these calibration requirements helped the firm design the RxSpec 700Z to address the needs of unskilled end-users.

The RxSpec 700Z weighs 23 pounds and is packaged in a briefcase with a Windows-based laptop. The touch-screen interface, a first for ASD, increases user friendliness.Technological developments required for miniaturization included maximizing the optical throughput, as well as minimizing the amount of stray light during analysis. “The traditional approach to minimizing stray light is to increase the distance between optical elements. Since we desired to maintain a small size, we instead utilized optical elements—for example, concave holographic gratings—and optimized baffling to achieve high stray-light performance, while maintaining a small size,” explained Dr. Curtiss.

In contrast to the RxSpec 700Z, Ocean Optics’ latest product for the portable molecular spectroscopy market, the Jaz, has the capability to undertake numerous applications in many markets. This is due in part to the wide-ranging applications of the system’s UV-vis technology, as opposed to the application-specific calibration requirements of NIR systems.

Released in January 2008, the Jaz is also a departure from previous portable systems created by Ocean Optics. According to the company, its preconfigured miniature portable spectrometers, many weighing less than five pounds, are designed for use in labs seeking less expensive options than benchtop systems, as well as by researchers in the field who can synch the devices with lap tops. “For many years, folks have taken our miniature spectrometers into the field, running the spectrometer from the power of the PC, but this approach has limitations—you still need to power light supplies, if you’re using them, and still need to recharge the PC every so often,” explained Rob Morris, Ocean Optics’ director of Marketing. “Jaz is the first system we’ve offered that is truly portable—a completely monolithic device with built-in computing power, display and battery,” he said. “Now, instead of a footprint slightly larger than the typical laptop, you’re looking at a footprint that’s about the same dimensions as a can of tennis balls or a can of Pringles potato chips, albeit in a rectangular shape and not a conical shape.” With the microprocessors’ power, environmental, horticultural, solar and pollution testing applications can be done while traveling farther than previous Ocean Optics systems allowed, with the data stored and processed in the unit. Also, the system’s batteries can be recharged using solar cells.

The system is sold in a series of stackable modules with different functionalities, including a display module, light source modules and memory modules. Up to three spectrometry modules can be used in one system for multiple-point analysis. Additional modules currently under development include GPS and voice-recording capabilities. Another important first for the Jaz is the Ethernet module. “[The Jaz’s] true power lies in its ability to be integrated into a network of spectrometers, using the World Wide Web as the pathway, so that the value resides in the network itself, not the individual pieces. Think of the relationship of an iPod to the iTunes Store, and you get the idea,” explained Mr. Morris. Ease of networking and the nondedicated nature of the system also allows for the freer movement of the system along the line in manufacturing applications. For example, the same system can be used for both raw stock and finished-goods testing.

The future of portable molecular spectroscopy instruments is bright. Numerous products have been released with more user-friendly interfaces and software, which, combined with better technology, give easy to read and accurate results. One of the current developments that could further spur market growth is the use of portable molecular spectrometers by unskilled end-users outside of the lab. In addition, the improved harnessing of the latest networking and Internet capabilities will lead to new applications in the field, and may even facilitate the creation of new markets.

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