Disclosed are methods for determining and classifying aircraft air contaminants using contaminant analyzers comprising a contaminant collector comprising a membrane and a heater vaporizing captured contaminants; a gravimetric sensor generating a proportionate response when contaminant mass is added to or removed from the sensor, the sensor arranged to receive contaminants desorbed from the membrane when the membrane is heated; a frequency measurement device, measuring the response generated by the sensor as the contaminant is added to and removed from the sensor; a computer readable medium bearing a contaminant recognition program and calibration data; a processor executing the recognition program, the program including a module classifying contaminants by type, and a module using the calibration data for comparison with magnitude of the response generated by the sensor to calculate contaminant concentration; and, a pump, generating flow of aircraft air through the contaminant collector before and after the membrane is heated.