Direct analysis of camptothecin from Nothapodytes nimmoniana by desorption electrospray ionization mass spectrometry (DESI-MS).

Desorption electrospray ionization was employed for fast and direct ambient detection of the anti-tumor drug, camptothecin, and its derivative, 9-methoxycamptothecin in Nothapodytes nimmoniana. Different parts of the plant such as leaves, stems and bark were examined. The ion intensities suggest that the concentration in bark is higher than that in the leaves and stems. The method does not require any sample preparation or preseparation. The identity of the alkaloids was further confirmed by tandem mass spectrometry.