The European Council directive 1999/13/EC defines volatile organic compounds (VOCs) as “any organic compound having at 293.15 K a vapor pressure of 0.01 kPa or more, or having a corresponding volatility under the particular conditions of use”.
In our daily life, these molecules are notably responsible of the flavor of food products, as well as of the fragrance of essential oils used in the cosmetics industry.
In nature, these molecules are produced by bacteria and fungi.
They are also synthesized by plants (flowers, fruits, leaves and roots)  and animals (humans, insects, etc.).
The profiling of VOCs emitted by living organisms takes an increasing importance in various scientific domains like in medicine, in food sciences or in chemical ecology.
For instance, in medicine, non-invasive diagnosis techniques of cancer based on the profiling of VOCs from the exhaled breath have been developed. To this end, a variety of novel sensing approaches and nanomaterial based sensors are being used in volatolomics research.
In the field of chemical ecology, gas chromatography coupled to mass spectrometry (GC-MS) is often used to characterize the volatile semiochemicals involved in the biotic interactions taking place aboveground  and belowground  between plants, insects and phytopathogens.