Study On β₂-agonists And Plant Hormone By Capillary Electrophoresis And Its Combining Techniques

In this thesis, capillary electrophoresis coupling with diode arraydetector/electrospray ionization mass spectrometry was investigated and applied toseparation and determination of β2-agonists and plant hormone. Different separationmodes and on-line sample stacking methods were designed and applied. The maincontents of this thesis are divided into three parts as follows:The first part is also chapter1. In this chapter, the research progress ofβ2-agonists and plant hormone was summarized. In addition, the principles andapplications of capillary electrophoresis and its differert separation modes wereemphatically introduced. Then on-column pre-concentration techniques were alsosummarized. Finally, the content, purpose and signification of this thesis weredescribed.The second part includes chapter2, chapter3and chapter4. In this part,comparative study on different separation modes of capillary electrophoresis inanalyzing β2-agonists were described.In chapter2, a new method for the determination of β2-agonists withmicroemulsion electrokinetic chromatography (MEEKC) separation mode wasdeveloped. The method used the hydrophobic micro emulsion as pseudo-stationaryphases. The detection limits (S/N=3) were in the range of0.008-0.2μg/mL, and thedetection of trace salbutamol in urine samples was achieved.In chapter3, a sensitive and rapid method using CE-ESI-MS for thesimultaneous separation and determination of clenbuterol, salbutamol, terbutaline andformoterol in human urine was established. In order to make the determination oftrace analytes in in vivo biological samples become possible, field-amplificationsample stacking was used to enhance the sensitivity. Compared with the conventionalelectrokinetic injection, the enhancement factors had been greatly improved as muchas125-332folds and the lowest detection limit was0.08ng/mL. The method wasrapid and suitable for the determination of trace salbutamol in real urine samples.In chapter4, based on the study of CE-ESI-MS, a silica-based monolithic column was prepared by sol-gel process. A CEC-ESI-MS detection system wasestablished for the analysis of six β2-agonists. The developed method was simple,robust and sensitive and showed wider linear range.The third part is chapter5. CE combined with MS was applied to thesimultaneous separation and determination of five plant hormones. Combining theadvantages of CE with superiorities of MS, the method was rapid, robust and sensitive.Furthermore, the method was applied to the assay of five plant hormones andqualitative and quantitative determination of naphthylacetate in rooting powder.