Abstract: A surface acoustic wave sensor in which instrument drift resulting from accumulated surface contamination is minimized. The sensor includes a piezeoelectric substrate defined by an outer surface and a plurality of interdigitated electrodes mounted thereon. The electrodes are defined by one or more exposed portions and an unexposed portion abutting the outer surface of the piezoelectric substrate. An inert coating layer on the outer surface of the piezoelectric substrate and the exposed portions of the electrodes is provided, and can be a perfluoro-silane type compound, a perfluoro-trichloro-silane type compound, a perfluoro-acrylate type compound, polytetrafluoroethylene, or heptadecafluorodecyltrimethoxysilane.

Abstract: A method for identification of chemicals in a sample using a gas chromatograph, a surface acoustic wave (SAW) sensor coupled with the gas chromatograph to define a gas chromatography (GC)/SAW system, and a Raman spectrometer. The method includes receiving SAW frequency response data generated by the SAW sensor, receiving Raman spectrum data generated by the Raman spectrometer, producing a Raman spectrum corresponding to an eluted component of interest based upon an integration of the Raman spectrum data, identifying a set of one or more candidate chemicals for the eluted component of interest based on a corresponding peak of the SAW frequency response data, and searching a Raman database for a match between the produced Raman spectrum and a chemical in the Raman database from among the set of candidate chemicals for the eluted component of interest.

Abstract: A method for identification of chemicals in a sample using a gas chromatograph and a surface acoustic wave (SAW) sensor coupled with the gas chromatograph to define a gas chromatography (GC)/SAW system. The method includes receiving a temperature profile defining a varying target temperature as a function of time, separating one or more eluted components from a sample with the gas chromatograph, adjusting a temperature of the SAW sensor in accordance with the temperature profile as the one or more eluted components are separated from the sample by the gas chromatograph, generating SAW frequency response data with the SAW sensor, the SAW frequency response data including one or more peaks corresponding respectively to the one or more eluted components separated from the sample, and identifying a set of one or more candidate chemicals for an eluted component of interest based on a corresponding peak of the SAW frequency response data.