Global metabolite profiling and diagnostic ion filtering strategy by LC-QTOF MS for rapid identification of raw and processed pieces of Rheum palmatum L.

Due to its variety of functions, rhubarb has been used for thousands of years in many countries. It is commonly used after processing. Processing usually affect the chemical profile and the contents of active compounds in herbals, leading to changes of their bioactivities. Here, an approach of metabolite profiling and diagnostic ion filtering strategy with liquid chromatography-quadrupole/time-of-flight mass spectrometry was established for rapid identification of raw and processed pieces of Rheum palmatum L. (RPL). The comprehensive and unbiased information of 30 batches of RPL covering raw and two general processing methods were given by metabolomic profiles. Using molecular feature extraction algorithm, non-targeted compounds were analyzed in minutes. In total, 73 characteristic markers were extracted and identified by diagnostic ion filtering. They have been further analyzed by partial least squares-support vector machine-based pattern recognition. The comprehensive and rapid method for raw and processed pieces of RPL classification shows good sensitivity, specificity and prediction performance.