Mass spectrometric detection was performed using an Agilent 6495C triple quadrupole instrument operated in dynamic MRM mode with a cycle time of 300 ms, resulting in a minimum dwell time of 5.82 ms. Gas temperature was 200°C, gas flow 14 L min -1 , nebulizer 40 PSI, sheath gas 250°C, sheath gas flow 12 L min -1 , and capillary and nozzle voltage were set to 3000 V and 1500 V, respectively, in both positive and negative ionization mode. Individual MRM transitions and collision energies are provided in Table .