The United States Patent and Trademark office has awarded another patent (US 8,703,502) to Athula Buddhagosha Attygalle, research professor in the Department of Chemistry, Chemical Biology & Biomedical Engineering and his coworkers for their invention on “Analyte Identification by Charge Exchange for Sample Analysis Under Ambient Conditions.” Earlier this year, Attygalle group received a patent for their Helium Plasma Ionization (HePI) technique.
“This was primarily the work of Chang-Ching Chan. one my graduate students,” says Attygalle. Chan, who received his PhD from Stevens in 2011, was a part-time student who came from the Analytical Research and Development laboratory of Bristol-Myers Squibb Company, New Brunswick, New Jersey, USA. Mark S. Bolgar and Scott A. Millar, also from Bristol-Myers Squibb, are the other two inventors named in the patent.
Mass spectrometry (MS) is a powerful analytical tool used to measure the masses of molecules. In addition, it is one of the most sensitive methods available for detection and characterization of chemical compounds. In order to carry out mass spectrometric analysis the molecules must be vaporized and electrically charged.
The invention of Attygalle and his co-inventors describe that a nebulized spray of charged solvent molecules can be used to ionize analytes present on solid surfaces. By this technique, analytes present on the surface are desorbed and ionized by a charge exchange process. The acronym DICE has been proposed to describe this Desorption Ionization by Charge Exchange process.
Attygalle says “by this method, we can detect active ingredients present in pharmaceutical tablet directly, without the need of any sample preparation.” Moreover, the DICE technique does not produce undesired metal cation adducts, generated by most other desorption ionization methods.