Patent ID: 8589084

Claim:
A method of detecting ethanol in an exhaust gas emission from a spark ignition engine burning an ethanol/gasoline blend, the method comprising the steps of: collecting a sample of said emission suspected of containing ethanol; ionizing the sample to form a plurality of forming charged molecular species, the ethanol in the sample a charged molecular species having a mass/charge ratio of 31 atomic mass units (amu); separating the plurality of charged molecular species using mass spectrometry to produce a mass spectrum; and detecting the charged molecular species having a mass/charge ratio of 31 amu to detect ethanol in said exhaust gas emission; wherein said method does not include separation of molecular species in the exhaust gas sample prior to ionization; and wherein detection of the charged molecular species having a mass/charge ratio of 31 amu is indicative of the presence of ethanol in the emission.