Accurate Mass Determination of Platycosides Prepared by Macroporous Resins Using High-Resolution Mass Spectroscopy and Optimization Methods

The method using macroporous resin for isolation of platycosides from Platycodi radix extract was developed. The platycosides were detected and analyzed using quadrupole time-of-flight mass spectroscopy in negative ion mode. The employment of chemometric methods effectively reduced the influence of signal intensity or noise on the mass accuracy. Finally, the monoisotopic masses were accurately measured, and relative isotopic abundances of the ions were further investigated. The compound match was obtained by comparison with a specific monomer's database, and the optimal results allow researchers to narrow their database search window. In addition, the approximate elution order of some isomers was determined via comparison with mass spectrum and chemical structure analysis.