High-Resolution QTOF-MRM for Highly Accurate Identification and Quantification of Trace Levels of Triterpenoids in Ganoderma lucidum Mycelium

Abstract

The accurate quantification of triterpenoids in Ganoderma lucidum mushroom in the mycelium stage is challenging due to their low concentrations, interference from other possible isomers, and the complex matrix. Here, a high-resolution quadrupole-time-of-flight mass spectrometry “multiple reaction monitoring” with target enhancement (HR-QTOF-MRM) method was developed to quantify seven target triterpenoids in G. lucidum. The performance of this method was compared against an optimized QQQ-MRM method. The HR-QTOF-MRM was shown to be capable of distinguishing target triterpenoids from interferent peaks in the presence of matrices. The HR-QTOF-MRM LOD and LLOQ values were found to be one to two times lower than those derived from the QQQ-MRM method. Intraday and interday variabilities of the HR-QTOF-MRM demonstrated better reproducibility than the QQQ-MRM. In addition, excellent recoveries of the analytes ranging from 80 to 117% were achieved. Spiking experiments were carried out to verify and compare the quantitative accuracy of the two methods. The HR-QTOF-MRM method provided better percent accuracy, ranging from 84% to 99% (<3% RSD), compared with the range of 69 to 114% (<4%RSD) given by the QQQ-MRM method. These results demonstrate that the new HR-QTOF-MRM mode is able to improve sensitivity, reproducibility, and accuracy of trace level analysis of triterpenoids in the complex biological samples. The triterpenoid concentrations were in the range of nondetect to 0.06–6.72 mg/g of dried weight in fruiting body and to 0.0009–0.01 mg/g of dried weight in mycelium.

Evaluation of Quantitative Platforms for Single Target Mass Spectrometry Imaging

“…Mass analyzers cover a wide terrain of mass resolution and analysis speed, as well as offering potential confirmatory techniques, a la tandem methods (MS/MS, MS 2 , MS n ). Triple quadrupole (QQQ) instruments can uniquely identify species via MS 2 experiments, with effectively no background noise through multiple-reaction monitoring (MRM) acquisition mode [ 43 , 44 ]. In MRM-mode, they are also fast instruments, with scan times on the order of milliseconds, slowed only by the time of reaction in the collision cell (typically 50 ms or less).…”