Functional groups: chemical identification basic compounds

There has recently been considerable interest in the detection and identification of air-borne volatile compounds in such diverse areas as quality control of perfume to detection of toxic gases. Miniaturization, the potential low cost of sensors and the variety of applications promise an enormous market (29, 30), Chemical sensors (29) for volatile compounds operate on varied principles and can be classified according to the method of functioning into basic groups such as electrical (field-effect transistors, metal oxide semiconductors and organic semiconductors), optical (spectrophotometric, luminescence, optothermal) and sensors that are sensitive to a change of mass (piezoelectric and acoustosurface). 

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