Investigation Of The New Technology About Micro- Concentration And Micro-separation In CE

High performance capillary electrophoresis (HPCE), established in the 1980's, is a kind of separating and analytical technique with high separation efficiency. Because the mobile phase is electrically driven, there isn't the phenomenon of band broadening in HPCE as in HPLC, and the resolution is higher. At the same time, a great many options make it have a better separation efficiency. In addition, many herits such as low-consumption, pidness, simpliness, capability of anti-interference and anti-pollution are beyond comparison by liquid chromatography. Owing to these, it has been widely used in the fields such as food, drug, environment, and especially the biochemistry.In this thesis, the development and application of CE and it on-line micro-concentration techniques and micro-separation modes were reviewed. The following reports were mainly presented for the application and elementary study of on-line micro-concentration and separation technology of CE. The major content is described as follows:1. In the area micro-concentration, on base of our groups, study, the on-line single drop microextraction of CE using the drived force of electroosmotic flow (EOF) as the pump was developed. The high enrichment factors of acidic samples and alkaline samples were realized by using on-line two-phase SDME technology respectively.The high enrichment factors of the neutral sample-dimethyl phthalate and diethyl phthalate were realized by using on-line three-phase SDME technology and the separation mode of micellar electrokinetic chromatography. This technology greatly reduced the detection limits of samples and improved the detection sensitivity of CE. Besides, compared to the pressure-driven online SDME, this technology is more economical, convenient and easy to be controlled, because it only needs the high-voltage power control, without any external pressure device.2. In the area micro-concentration, a novel amphiphilic silica-based nanoparticle having surface-bound octanoyl-aminopropyl moieties (OA-NP) was successfully prepared and characterized by elemental analysis, infrared spectrometry (IR), and scanning electron microscopy. The potential use of OA-NP as pseudostationary phase (PSP) in CE for separation of charged compounds was investigated. As expected, fast and efficient separation of four aromatic acids was obtained with high column efficiency for they migrate in the same direction with the EOF (co-EOF) under optimum experimental conditions.As the octyl which was bonded in the group, could participate in the distribution and retention of neutral compounds. So the OA-NPs could improve the separation of neutral compounds and increase column effect. The nanoparticles are more convenient and easier to implement because of no electricity chromatography steps such as filling and preparation of the plunger compared with the conventional capillary electrochromatography.