The gas chromatography-mass spectrometry system (GC-MS) allows the determination of organic compounds. The gas chromatograph consists of a 6890N GC (Agilent Technologies) equipped with an automatic autosampler. The mass spectrometer (MSD 5973, Agilent Technologies) consists of a quadrupole low-resolution mass analyzer. The instrument allows the ionization of the analytes by means of the electron ionization source and the acquisition can be done in both full scan and selected ion monitoring modes. Data acquisition is done with the ChemStationTM software whereas data processing is carried out with MassHunterTM software allowing the use of the NIST spectral library for target and suspect screening approaches.