Mass spectrometry (MS) is a powerful analytical tool used to measure the masses of molecules. It is also one of the most sensitive methods available for detection and characterisation of chemical compounds. In order to carry out mass spectrometric analysis, the molecules must be vaporised and electrically charged.
Stevens researchers have received a patent for a new mass spectrometric technique called Helium-Plasma Ionisation Mass Spectrometry (HePI-MS). This versatile ionisation method enables sampling of materials under ambient conditions by placing them directly in the spectrometer.
Stevens has signed a licensing agreement with Plasmionix, LLC, who will develop, together with Scientific Analytical Instruments (SAI) in Manchester, United Kingdom, this technology invented by Athula Buddhagosha Attygalle, a Research Professor in the Department of Chemistry, Chemical Biology & Biomedical Engineering, and his colleagues.
In fact, Freneil Jariwala, a Stevens PhD graduate, has been recruited by SAI to implement the technology transfer. Postdoc Zhihua Yang and PhD candidates, Julius Pavlov and Rekha Gangam, also contributed to the development of the HePI-MS technique.
“We can tell if someone has washed their hands,” says Attygalle. “All of us carry a reasonable amount of lactic acid on our skin, and we get a signal for it just by placing your hands in the instrument.”
The Stevens technique also provides a rapid way to detect explosives, including inorganic substances, in amounts as tiny as one nanogram (one millionth of a milligram), for potential use at airports.
Attygale explains that many explosives use inorganic compounds, such as saltpeters. We are all aware, he says, of the disturbing reality of misuse of nitrate fertiliser for the construction of improvised explosive devices—all major ground terrorist attacks in the West—from the Oklahoma City bombing in 1995 to the events in Oslo in 2011, employed ammonium nitrate-based bombs.
“Most explosives are organic—carbon based,” says Attygalle. “Inorganic explosives are much harder to detect because they are mostly salts—they are less volatile.”
According to Attygalle, typical mass spectrometric techniques involve rigorous sample preparation, and extraction. Overall analysis time and expense per sample can be significant. HePI-MS does not require most of these sample preparation procedures.
HePI-MS can be used for a variety of applications, from distinguishing brands of chewing gum to potential healthcare applications. Researchers actually inserted a cured sausage to show the presence of nitrates and showed nicotine in an unlit cigarette, the results of which were published in Analytical Chemistry, 2014 86 (1), 928-935.
“Eventually, we will be able to sample, for example, the breath of an unconscious patient who has overdosed on drugs to determine what they have taken,” says Attygalle. “This method has the potential to save lives.”