Pharmaceutical samples were placed on the sample holder without any pretreatment. The active ingredients of the tablets can be desorbed and ionized by microwave plasma. Then full-scan mass spectra of the samples were obtained using both MPT-TOF-MS instrument and LTQ-XL-MS instrument. For CID experiments, the precursor ions were isolated with a mass-to-charge window width of 1.6 Da, and then subjected to CID with collision energy of 15%–35%. Mass spectra were recorded with an average time of 30 s, and all backgrounds were subtracted.