Data acquisitions were performed in the selected ion
monitoring (SIM; positive ion mode) mode using the interface
parameters. Other conditions were drying gas (N2) flow of 4 L/min, drying gas and vaporizer temperatures of 320 C, nebulizer
capillary voltage of 3 kV, corona current of 8 mA, fragmentor
voltage of 55 eV and pressure of 55 psig. Full scan analyses were
performed in the mass range of 50e500 Da for the spectral
identification of amino acids and sample co-extractives
respectively.