In Situ Analysis for Herbal Pieces of Aconitum Plants by Using Direct Analysis in Real Time Mass Spectrometry

In this study, an extend application was developed to in situ analyze the herbal pieces of Aconitum plants by Direct Analysis in Real Time Mass Spectrometry (DART-MS). Nearly all aconitine-type alkaloids can be desorbed and ionized in this method, including diester diterpenoid aconitines (DDAs), monoester diterpenoid aconitines (MDAs) and some other diterpenoid aconitines. The spectra of in situ analysis for the herbal pieces of aconitum plants are similar with that of their extracts. Radix Aconiti and Radix Aconiti Kusnezoffii can be distinguished from each other by the intensity differences of character fragment ions from MDAs, such as m/z 586, 572, and 556. The qualified and unqualified herbal pieces can be also identified by the relative abundances of DDAs. The RSD of the relative abundances of some character ions at m/z 556, 586, and 590 were 13.53%, 4.03%, and 12.03%, respectively. So this in situ analytical method can identify both the types of Aconitum preparata and their quality. It provides the following advantages in the analysis of Chinese herbs: fast detection without much pretreatment, high-throughput analysis, and reduction of pollution without any organic solvent.