For the monitoring and confirmation

For the monitoring and confirmation analysis, the multiple-ionreaction monitoring (MRM) mode was used. The MS/MS conditionswere optimized by the infusion of each of the standards (100 ng/mLin methanol) into the ESI source in the positive ion mode. The MRMmode was applied using two characteristics MRM transitions suchas the quantitative ion and confirmation ion. The selection criteriaof product ions were set to choose the two most intense ions toincrease the specificity of the product ions as well as to minimizethe level of the background. The MRM values for all of the scantransitions were as follows: scan width (m/z), 0.4; scan time (ms),150; and Q1 and Q3 resolution (FWHM), 0.7. The retention timesand MRM transitions of the pyrrolizidine alkaloids are summarizedin Table 1.