Growth fueled by life sciences, miniaturization
The study estimated the total market for MS at $3.175 billion in 2012 and expects it to reach $4.84 billion by 2017, a growth rate of 8.8 percent per year.
North America and Europe comprise more than half of current demand, 32 percent and 29 percent, respectively, with Asia-Pacific close behind at 27 percent. Top players are AB Sciex, Thermo Fisher Scientific, Agilent, Waters, Bruker, and Shimadzu. Growth in life science markets, particularly in pharmaceuticals and biotech, are fueling the growth in MS.
The report specifically cites miniaturization as a factor in the success of MS. A key consequence of MS instruments getting smaller and more feature-full but less costly has been the adoption of MS as a detector for high-performance liquid chromatography (HPLC) and gas chromatography.
The “mass detector”
Mass detectors for chromatography systems, while not quite ubiquitous, are steadily gaining ground in analytical labs, particularly in regulated industries as a complementary detector to UV. MS confirms the identity of peaks seen in ultraviolet traces and quantifies and identifies compounds lacking a UV chromophore. MS has become the go-to detector where science or regulation calls for lower limits of detection for impurities or target analytes. The knocks against MS, however, have been high cost and its requirement of specialized expertise.
Waters (Milford, MA) has recently introduced a new mass detector, the ACQUITY QDa Detector, for chromatography separations. According to Howard Read, senior product manager for mass spectrometry, the ACQUITY QDa Detector was a response to customer needs, particularly in pharmaceuticals.
“The driving trends here are risk mitigation, quality management, compliance, productivity, and cost control,” Read says. “We were responding to these ongoing needs of generating enhanced data for every sample analyzed, particularly for laboratories that do not currently employ mass spectrometry. Now they can make scientific decisions without having to send samples out or bring in an MS expert.”
This is only possible if the transition to MS from traditional detectors is seamless. MS had to be as familiar and accessible to analytical scientists as their optical detectors are. When designing the ACQUITY QDa Detector, Waters attempted to duplicate users’ familiarity with optical detectors with respect to use, size, affordability, and software integration.
From an end-user’s perspective, achieving ease of use is perhaps the most significant hurdle to adopting MS, which is still, for many, an intimidating technology. Unlike conventional MS instrumentation, which requires optimization and tuning for different separations, the ACQUITY QDa Detector is preoptimized and runs without adjustments or tuning for most samples. “Users have very little to do except turn it on. The ACQUITY QDa Detector is as close as you can get to out-of-the-box MS,” Read tells Lab Manager.
MS detection adds anywhere from $100,000 to $500,000 to the cost of an LC or GC system, according to Jason Weisenseel, PhD, technical leader at PerkinElmer (Orlando, FL). That puts it outside the scope of many laboratories that expect to pay a great deal less for the separations platform itself. The immediate benefits, depending on the type of MS, are additional mass and fragment information and about ten times the sensitivity of UV. Higher-end triple quad MS provides the quantitative precision of a UV detector—below 2 percent—and sensitivity close to the LC lower limit.
The emergence of alternatives to MS for companies that rely on high sensitivity and ultralow limits of detection could somewhat deflate the market projections cited earlier. In other words, all is not lost for chromatography labs that cannot afford MS. Sensitivity is constantly improving for ultraviolet and photodetector array (PDA) detectors, whose flow cells are evolving toward lower-volume, lower-dispersion, higher-sensitivity detector cell designs.
For analytes lacking a UV chromophore, such as sugars and most amino acids, evaporative light scattering (ELS) is becoming more prevalent and is sometimes used alongside MS detection. “ELS is sensitive and provides an important alternative to the older refractive index detectors, which cannot be used with gradients,” Weisenseel says.
LAESI solution to sample prep woes
A relatively new technique is changing the way mass spectroscopists view sample preparation. LAESI (laser ablation electrospray ionization) is a variant on standard electrospray ionization (ESI), long considered a “gentle” ionization technique for analyzing large, delicate biomolecules by MS. LAESI performs direct extraction and ionization for stand-alone samples or for profiling the distribution of biomolecules in a variety of sample types.
For example, researchers talk about merely “waving” samples before a LAESI device and achieving sufficient ionization for MS analysis. Says Haddon Goodman, LAESI platform marketing manager for Protea Biosciences (Morgantown, WV), “LAESI’s main advantage is operation at ambient pressure with no sample prep and no addition of matrix.”
Because it occurs at ambient pressure, LAESI allows users to analyze bacterial and fungal colonies for interesting natural products that may be channeled into, say, a drug development pipeline. “LAESI enables investigators to search through hundreds of thousands of colonies to find specific molecules of interest,”
Goodman tells Lab Manager. A group at the University of Oklahoma is screening fungal colonies for secondary metabolites, for example. “LAESI is just about the only way to analyze them at this level of throughput,” Goodman adds. “It allows users to submit samples that could previously not be analyzed by mass spec.” Goodman describes LAESI as a “post-sample introduction method.” Unlike LC, it does not take “heart cuts” of peaks. And by itself LAESI does nothing—it requires an MS to work its magic. “It’s a front end for MS,” Goodman says.
The no-sample-prep aspect of LAESI results from its operation. It uses a 2.94-micron laser tuned to the absorption lines of water. When the laser strikes the sample, it induces rapid boiling by exciting the OH bonds in water, thereby generating an uncharged ablation plume that ionizes in contact with charged electrospray and sweeps into the MS.
For additional resources on Mass Spectrometers, including useful articles and a list of manufacturers, visit www.labmanager.com/mass_spec
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