Recent Patent Describes a New Method to Separate and Characterize Ions
Scientists' approach employs time-dependent electric field with novel waveform profiles
Results: A new approach to identify ions in gases and separate their mixtures is the subject of a recent patent issued to researchers at Pacific Northwest National Laboratory. This method, termed High-Order Differential Ion Mobility Spectrometry (HOD IMS), provides new avenues for more complete separation of complex biological samples and more specific characterization of their components. Its use is envisioned in proteomics, metabolomics and environmental analyses. By reducing or eliminating the need for chromatographic or other liquid-phase separations before mass spectrometry, HOD IMS may accelerate analyses by an order of magnitude.
Why it Matters: Separating and characterizing ions is vital to numerous research areas, including the detection of biomarkers of cancer and other diseases, determination of the health risks of low-level radiation exposure, understanding natural bioremediation processes to enable their control and detection of explosives and chemical warfare agents. HOD IMS can improve and speed the analysis of gas-phase ions, alone and in conjunction with known methods of mass spectrometry, chromatography and ion mobility spectrometry.
Methods: Standard IMS separates ion mixtures based on the mobility of ions in a gas. In contrast, HOD IMS separations are based on their higher order (second or higher) derivative of mobility with respect to the intensity of the electric field through which ions move. A U.S. patent was awarded to PNNL inventors Alexandre Shvartsburg, Richard D. Smith, and Gordon Anderson in November 2008.
Acknowledgments: PNNL is advancing science to achieve predictive understanding of multi-cellular biological systems. Portions of this work were supported by the National Institutes of Health National Center for Research Resources. The HOD IMS method was developed using resources at the U.S. Department of Energy's Environmental Molecular Sciences Laboratory, a national scientific user facility located at PNNL.
Reference: Shvartsburg AA, RD Smith, and GA Anderson. "Method and Apparatus for High-Order Differential Mobility Separations." U.S. Patent 7,449,683 (2008).