A method and an aircraft air contaminant analyzer for determining and classifying air contaminants, providing a sample flow path and bypass flow path bypassing the sample flow path, are disclosed, the analyzer comprising a contaminant collector comprising a medium desorbing captured contaminants, the collector providing a first sample flow path; a heater vaporizing captured contaminants; a bypass comprising a channel including a second sample flow path, the channel bypassing the collector; a sensor responding when air contaminant mass is added to or removed from the sensor, for classifying contaminant type; the sensor receiving contaminants desorbed from the medium; a frequency measurement device measuring the response generated by the sensor as the air contaminant is added to and removed from the sensor; a computer readable medium bearing a contaminant recognition program and calibration data; and, a processor executing the program, the program including a module classifying the contaminant by type.