Physalin B and physalin H (internal standard, IS) were separated on an Agilent Eclips XDB C8 column. 
Agilent Eclips XDB C8 column
MS detection was performed on a triple quadrupole tandem mass spectrometer in the multiple reaction monitoring mode with a positive eletrospray ionization source. 
triple quadrupole tandem mass spectrometer
MS detection was performed on a triple quadrupole tandem mass spectrometer in the multiple reaction monitoring mode with a positive eletrospray ionization source. 
positive eletrospray ionization source