The CE system was hyphenated with an Agilent 6490 triple quadrupole mass spectrometer (QqQ MS, Agilent Technologies, Santa Clara, CA, US) equipped with an ESI source via a coaxial sheath-flow interface with a standard triple-tube sprayer (P/N G1607B) from Agilent Technologies. The sheath liquid was delivered at a flow rate of 3 µL/min, using a 2300 Series isocratic pump purchased from Agilent Technologies (Waldbronn, Germany) equipped with a 1:100 split. Electrospray ionization was operated in positive mode, and spectra were acquired via SRM measurements. The pressures and injection volumes used during the validation are described in section 4.2. The precursor and productions monitored for each compound and the collision energies are reported in Table in the supplementary information. The following source parameters were used: the nebulizing gas pressure was set at 0 psi and the sheath gas at 11 L/min and 150 • C. The capillary voltage was adjusted to 5500 V. The ion funnel voltages were set at 150 V for the high-pressure funnel and 60 V for the low-pressure one. The EMV voltage was set at 400 V and the cell accelerator voltage at 5 V. For all transitions, precursor and product ion selection was performed with a resolution of 1.2 and 0.7 m/z, respectively. Data acquisition and instrument control were performed using MassHunter version B.08.00 (Agilent, Santa Clara, US).