The targeted HILIC-MS/MS analysis was performed on a Waters Acquity UPLC I-class system from Waters (Milford, MA, USA) coupled to an AB Sciex QTRAP 6500 mass spectrometer (Concord, ON, Canada). The needle wash was acetonitrile:water (1:1,v/v). The column, mobile phase, autosampler temperature and column oven temperature were the same as described in section 2.4. with a slight modification in the gradient as shown in Table . Table . Gradient for HILIC-MS/MS analysis. The MS/MS experiments were conducted on a Turbo V source. The analysis was conducted in positive ion mode and analytes were monitored in scheduled multiple reaction monitoring (sMRM) mode. The mass spectrometer was operated at the following settings: the curtain gas (N2) pressure was set to 25 psi, and the collision gas (N2) was maintained at a medium level.