The ultra-high performance liquid chromatography-tandem mass spectrometry system (UHPLC-MS/MS) allows the determination of organic compounds. The UHPLC system consists of an LC Agilent 1290 Infinity II instrument (Agilent Technologies) equipped with an automated autosampler, a column oven and a quaternary pump (up to 1300 bars and 5 mL/min). The chromatograph is coupled to a low-resolution mass spectrometer consisting of an Agilent 6430 Triple Quadrupole MS/MS (QqQ, Agilent Technologies) which provides a high selectivity and sensitivity. The QqQ is equipped with both an electrospray ion source (AJS-ESI) to improve the ionization of polar compounds and an atmospheric pressure chemical ionization (APCI) source source to cover low- and mid-polar compounds, thus extending the coverage of the chemical space. Additionally, the mass spectrometer provides different acquisition modes (fullscan, SIM, MRM, etc.) allowing the application of target approaches. Data acquisition and data processing are done with the MassHunterTM software.