A New Method For The Analysis Of Active Ingredients In Natural Medicines Based On High Sensitivity Mass Spectrometry

Natural medicines are receiving more and more attention in promoting human health.The establishment of new methods for rapid,sensitive and reliable qualitative and quantitative analysis of active ingredients in complex matrices has always been a hot spot in natural medicine research.Quadrupole-time-of-flight mass spectrometry（Q-TOF/MS）and ion mobility mass spectrometry have extremely high resolution,large mass-to-charge ratio range and high-speed acquisition capabilities.Multi-mode liquid chromatography coupled with mass spectrometry can greatly improve the efficiency of separation and structure identification of active ingredients in natural medicines.This thesis contains following parts.1.An ultrasonic-assisted extraction combined with ion mobility-mass spectrometry method was proposed to identify and classify different types of hawthorn samples.Various parameters affecting the separation of liquid chromatography were studied and optimized,including the type of mobile phase,the concentration of formic acid water and the type of chromatographic column.In addition,mass spectrometry data and multivariate analysis（such as principal component analysis and cluster analysis）can be used to distinguish common hawthorn,hawthorn leaves,southern wild hawthorn and northern wild hawthorn samples.The method validation experiment showed good linearity（R²>0.9910）,and the detection limit was 0.53 to 83.33 ng/m L.2.A matrix solid phase dispersion（MSPD）microextraction combined with supercritical fluid chromatography-ion mobility mass spectrometry was used to analyze the effective components in Dendrobium officinale.On the ZORBAX RX-SIL column,the target analytes were eluted with a gradient of supercritical CO₂within 8 min.After measuring the Collision cross section of the target compounds,the stationary phase,mobile phase,Make-up solution,temperature and back pressure were optimized.A series of validation studies were carried out on this method under the optimum conditions,and the linear relationship was good.The detection limit was1.415～8.824 ng/m L.3.Using online electrochemistry combined with Q-TOF/MS to study the prototype and metabolites of alkaloids,phase I and phase II metabolism were simulated in the electrochemical reaction cell.In a thin-layer battery equipped with a glassy carbon working electrode,the metabolism of coptisine and jatrorrhizine was simulated;a boron-doped diamond working electrode was used to simulate the metabolic pathways of berberine and palmatine.This experiment detected metabolites such as dehydrogenation,demethylation,methylation,hydroxylation,and two hydroxylation.Finally,ultra-high performance liquid chromatography（UHPLC）coupled with mass spectrometry was used to analyze the metabolites of liver microsome incubation.4.Green ionic liquid was used as elution solvent of MSPD,calixarene as solid dispersant,and UHPLC-Q-TOF/MS was used for the separation and determination of organic acids in Chaenomeles speciosa.Five main parameters of MSPD were optimized,such as adsorbent type,grinding time,adsorbent dosage,elution solvent type and concentration.The linear curves of the analytes ranged from 0.01 to 500μg/m L.The correlation coefficient（R²）was higher than 0.9995 and the detection limit was in the range of 0.202～1.056 ng/m L.The recoveries of the target compounds at the two spiked levels ranged from 82.19%to 113.36%.