SPE固相萃取技术的原理类型方法及应用.pptVIP

固相萃取（SPE）技术;固相萃取技术SPE;一、概述;一、概述;一、概述 样品类型;二、SPE基本原理;二、SPE基本原理;三、SPE法的优点;四、 SPE装置;五、 SPE的类型;五、 SPE的类型 硅胶表面的官能团;五、 SPE的类型;五、SPE的类型  以硅胶为基质的固定相的分类;五、 SPE的类型 硅胶键合非极性固定相;五、SPE的类型 分析物与非极性固定相的作用力;五、 SPE的类型 硅胶键合极性固定相;五、 SPE的类型 分析物与极性固定相的作用力;五、 SPE的类型 硅胶键合离子交换剂;SCX PRS CBA SAX PSA NH2;五、SPE的类型 分析物与离子交换剂的作用力;基体对选择合适分离机制有着重要影响（e.g.);五、 SPE的类型 混合模式固定相;六、 SPE方法的建立;SPE柱子类型的选择;1、Reversed-phase bonded silica sorbents having alkyl groups such as octadecyl (C18, C18), octyl (C8, C8), or ethyl (C2, C2) covalently bonded to the silica gel backbone or cyclohexyl (CH) or phenyl groups and sorbents composed of polymeric resins such as polystyrene–divinylbenzeneinteract primarily with analytes via van der Waals forces. 2、Nonionic watersoluble compounds can be retained by reversed-phase sorbents but may not be as well retained as analytes that are soluble in methanol or methanol–water miscible mixtures. 3、Normal-phase polar sorbents, such as silica, alumina, and Florisil, and cyano (CN) bonded phases interact by polar-dipole/dipole forces between polar functional groups in the analyte and the polar surface of the sorbent. 4、Amino (NH2) and diol sorbents interact with analytes by hydrogen bonding. 5、Hexane-soluble analytes are best retained by normalphase sorbents such as silica or Florisil or polar functionally substituted bonded phases such as amino or diol. 6、Strong cation-exchange (SCX) and strong anion-exchange (SAX) sorbents interact primarily through electrostatic attractions between the sorbent and the analyte. 7、Graphitized carbon sorbents exhibit both nonspecific van der Waals interactions and anionexchange, or electrostatic, attraction for analytes.;1、Dependence of Sorption on Sample pH If a compound is ionizable, the e