Rapid Analysis of Liuwei Dihuang Pills Using Surface Desorption Atmospheric Pressure Chemical Ionization Mass Spectrometry

A surface desorption atomospheric pressure chemical ionization mass spectrometry (SDAPCI-MS) method was developed to obtain the fingerprint of Liuwei Dihuang pills (LDP) with minimal sample pre-treatment. In the open environment, humid air was corona discharged to produce reagent ions for desorption ionization of the analytes on the surface of the LDPs. Then the analyte ions were guided into the ion trap mass analyzer of the LTQ instrument for mass analysis. Identification of the components of interests such as gallic acid, paeonol and ursolic acid in Liuwei Dihuang pills were demonstrated by tandem mass spectrometry (MS/MS). Principal component analysis (PCA) of the mass spectral fingerprint data was used to differentiate the samples from four manufacturers. The results show that this method is a useful analytical tool for quality control in pharmaceutical industry, particularly for the traditional Chinese medicine production.