Simultaneous quantification of 19 diterpenoids in Isodon amethystoides by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry

A high-performance liquid chromatography with electrospray tandem mass spectrometry (HPLC-ESI-MS/MS) method was developed to characterize and quantify 19 diterpenoid compounds in Isodon amethystoides simultaneously. By employing a Diamonsil C-18 column, 19 constituents were separated within 15 min using a gradient elution consisted of methanol containing 0.1% formic acid and 0 1% aqueous formic acid The precursor and product ions of the analytes were monitored on a hybrid quadrupole linear ion trap mass spectrometer equipped with a turbo ion spray interface in positive and negative mode in a single run and quantified by a multiple-reaction monitor (MRM) All standard calibration curves showed good linearity (r(2) > 0.99) within the test ranges The precision was evaluated by intra- and inter-day tests, which revealed relative standard deviation (RSD) values within the ranges of 1 06-3.25% and 1 56-3 84% The recovery studies for the quantified compounds were between 95 82 and 108 3% with RSD values less than 1 86% The results indicated that the method is simple, rapid, specific and reliable This method was successfully applied for identification and quantification of 19 diterpenoids in 11 batches of I amethystoides. The results showed that the contents of diterpenoids in I amethystoides from different sources were widely varied. (c) 2010 Elsevier B V. All rights reserved.