| The sample pretreatment process mainly refers to the application of various separation methods in the sample preparation process.It is the most time-consuming step in most analysis processes and is the key to the successful analysis of the target in a complex matrix.The development of efficient,robust,and environmentally friendly new sample preparation techniques has always been a hot field in analytical chemistry research.Solid phase microextraction(SPME)is a new type of sample pretreatment technology that is currently receiving much attention.It integrates extraction,concentration,and sample injection.This technology has undergone nearly three decades of development in devices and probes.Great progress has been made in materials,extraction thermodynamics and kinetic theory,and expansion of application objects.In this paper,stainless steel fiber wire is used as the probe matrix,and the mesoporous carbon microspheres are fixed to the solid-phase microextraction probe by the sol-coagulation method.The new probe is applied to the rapid analysis of volatile components of plants.The first chapter outlines the basic concepts and principles of solid-phase microextraction,and summarizes the application of new SPME substrates and coating types,coating fixation methods,and solid-phase microextraction technology in the analysis of plant volatile components.Based on the above discussion,the idea,research content and technical route of this thesis are proposed.In the second chapter,a new method for rapid and robust preparation of sol-gel probe coating was constructed.Based on the sol-gel method,a hydroxysilicone probe coating was prepared on the surface of stainless steel fiber wire;ordered and mesoporous carbon microspheres were synthesized and characterized,Mesoporous carbon microspheres were embedded and crosslinked and coated on the surface of stainless steel fiber wire by sol-gel method to prepare mesoporous carbon hydroxyl silicone oil coating probe.Infrared spectroscopy,scanning electron microscopy,and thermogravimetric analysis were used to characterize the coating structure of the probe;the results showed that the mesoporous carbon coating increased the thermal stability of the hydroxysilicone oil coating.Taking Haizhou Elsholtzia splendens essential oil and A.argyi leaf powder as targets,the hydroxy silicone oilsol-gel coating probe and mesoporous carbon hydroxy silicone oil sol-gel coating probe were used to investigate the extraction of plant polar and non-polar volatile components The performance was analyzed theoretically,the relationship between the extraction performance and structure of the new coating probe was discussed,and a new method for rapid analysis of plant volatile components in headspace was established.The third chapter is to optimize the headspace solid-phase microextraction conditions,and use the principal component analysis method to apply the mesoporous carbon microspheres hydroxy silicone oil sol-gel coating probe to the rapid identification of the quality of the moxa in Qi Chun.It provides data support for rapid identification and expands the application scope of solid phase microextraction technology in the analysis of plant volatile components.The results show that the weak polar mesoporous carbon microsphere hydroxysilicone SPME coating prepared by the sol-gel method can extract the volatile components in moxa,which can be applied to moxa when combined with GC-MS technology(Column)Rapid analysis of product volatile components.Chapter four applies the mesoporous carbon-hydroxyl-silicone sol-gel coating probe to the rapid analysis of the volatile components of two different types of camphor trees(oil camphor,camphor camphor),and at the same time the oil camphor and dragon The analysis results of volatile components of camphor camphor oil and camphor camphor and yin camphor leaf dry powder were compared respectively,and the reasons for the similarities and differences of the components were analyzed,which provided technical support for the rapid identification of different chemical species of camphor tree species,and provided an in-depth control of steam distillation.The reliability of the results of rapid analysis of plant volatile components and solid phase micro-extraction method provides data support.The results show that compared with steam distillation,the components collected by solid phase microextraction can more truly reflect the natural volatile components of plants. |
