Miniature Mass Spectrometry Instruments for Biomedical Applications

A multitude of disciplines within the biomedical, chemical, and pharmaceutical fields often rely on mass spectrometry (MS) as a means for identifying compound structure, quantifying metabolites, and measuring molecules in mixtures of varying complexities.

This highly sensitive approach for the study of biological systems is also used in drug discovery and is crucial in the development of potentially life-saving therapeutics. Large system size is perhaps the most common limiting factor that may be preventing widespread application of MS in the clinical environment. Additionally, complicated analytical methods can make the system impractical for some healthcare practitioners and nonmedical professionals.

Miniature MS has recently been introduced to help overcome size and weight limitations inherent in conventional MS tools. Benchtop MS instruments have become condensed and modified for portability and accessibility, and some miniature MS systems have been adapted for handheld use. Miniature MS technology has significant utility for chemical process control and environmental monitoring, among other applications. Being able to use miniature MS for in situ analysis, for example, has been one significant reason for developing miniature systems. Also, having a MS system that is approachable and easy-to-use by nonmedical professionals, like firefighters and inspectors of food safety, is also a driving force behind the expansion of miniature MS.

This technology will be highlighted in numerous talks at Pittcon in Chicago, IL, March 5-9, 2017. Sessions will be led by leading researchers in the field of MS and miniature MS, including R. Graham Cooks of Purdue University and Daniel Austin of Brigham Young University. Talks will be given on the subjects of ion traps and the miniaturization of MS, and numerous companies will be in attendance to demonstrate their mass spectrometer products and how they can be used in a variety of scientific applications.

A miniature MS is revolutionary in that it provides quick, easy clinical diagnostics and can sit in a physician’s office without sacrificing space. Mini 12, a miniature MS with an ambient ionization source and developed by Purdue University researchers, is an example of a successful miniature MS system. This miniature MS instrument has been designed for physicians or nurses who require a simple MS analysis in the clinical setting. A finger prick blood sample can be loaded into a cartridge and into the Mini 12 MS, automatically producing analysis of data. The cartridge contains a barcode that is read by a camera in the system, initiating the required analysis. Following a solvent spray onto the cartridge and a number of other processes, the MS scans are performed. This occurs without any operator intervention.

Minimizing MS size, while beneficial in some aspects, also has its own set of limitations. Size reduction of MS can lead to compromised performance of a MS; however, miniature MS has been specifically constructed to maintain a high level of accuracy and sufficient resolutions while offering automatic operation. All mass specs work in a vacuum to avoid intermolecular collision events and remove background signal. Since vacuum systems feature a considerable amount of weight and are fairly large in size, the vacuum represents one of the biggest challenges for shrinking a mass spectrometer.

An exciting application of miniature MS in surgery has been in the field of oncology, specifically brain cancer. A study from Purdue University and Brigham and Women’s Hospital and led by Robert Graham Cooks found that a tool that relied on desorption electrospray ionization, an ambient mass spectrometry analysis technique, was able to test brain tissue to identify cancer grade and type as well as tumor margins in brain surgery patients. Potentially, a miniature MS system that is being developed by this research team may be used for the same study of cancerous tissue, particularly in regard to their molecular structure.

Robert Graham Cooks, one of the authors of the paper, will be providing two talks at Pittcon 2017 in Chicago, Illinois, introducing a session about miniature mass spectrometers while also presenting his study, Searching for Biomarkers Using Ambient Ionization Mass Spectrometry. Pittcon 2017 will also present new, innovative studies in the field of miniature MS, including specific ion traps and novel ionization procedures. Bruker, Photonis, Waters, Hamamatsu, and Thermo Fisher Scientific are just a few of the key exhibitors this year, each providing information and demonstrations of their MS systems and new measurement technologies.