Portable mass spectrometry made easy
Nano-scale components have been successfully used to develop a portable MS device, according to work done by Luis Velásquez-García, Principle Research Scientist at MIT’s Microsystems Technology Laboratories (MTL; MA, USA), and colleagues.
The miniaturization of MS equipment presents a novel solution to the scientific need to conduct accurate, swift chemical tests while in the field, while also promising an inexpensive alternative to bulky laboratory systems.
The construction of a mass spectrometer roughly the size of a smartphone is an exciting prospect. At a fraction of the cost, the technology may signal an enormous breakthrough in making scientific analysis accessible in places where traditional MS is unfeasible, either as a result of limited resources or due to practical concerns. This is important not least because of the sheer range of potential applications for portable MS. Many areas, from environmental testing to forensic work, would benefit from such a device.
The device will perform exactly the same function as its larger relative. It will allow field researchers, or scientists with limited resources, to quantify the chemical composition of a sample by ionizing the material. The breakthrough from the lab at MIT’s MTL comes from the nano-scale engineering of individual MS components.
In particular, the engineers at MTL have succeeded in miniaturizing ionizing sources for gases and liquids, the ‘quadrupole’ responsible for differentiating the chemical compounds, and a vacuum pump. They have also managed to develop technologies to facilitate mass production of their inventions.
Miniaturization has its engineering benefits, Velásquez-García explained. For example, the nano-scale conical tips in the gas ionizer make the component low-voltage, and allow it to work at far lower vacuum pressures than in full-size devices.
The quadrupole, in turn, is an array of four parallel rods, which create between them an oscillating electrical current. These rods can be microfabricated in factory-style batches, and yet perform on par with full-size state-of-the-art systems. Finally, the vacuum pump, manufactured using chip fabrication techniques, has the bare minimum in terms of moving parts, lending itself to a miniaturized mass spectrometer design.
Smaller systems, as Velásquez-García elaborated, “probably consume less power, operate with smaller voltages, and can have higher throughput through multiplexing”, and are generally less ‘needy’ in terms of special conditions needed. A reduced requirement for a vacuum, for example, decreases the power needed to create a vacuum, and makes the whole device far more portable and energy-efficient.
In addition, the fact that the new components can be microfabricated in batches may see the cost of the system fall from tens of thousands of US dollars to under a thousand. The potential, particularly for applications such as carbon monoxide tests, is for miniaturized MS technology to eventually make everyday chemical analysis far more accessible.
Source: Mass spectrometry in your hand.
