The Study Of Highly Sensitive μSIA-CL Methodology For Analysis Of HOCl And For Assessment Of Antioxidant’s Scavenging Capacity Against HOCl

Flow injection analysis (FIA) or sequential injection analysis(SIA) has widely adaptability, high efficiency and high precision. Chemiluminescence(CL) analysis possess high sensitivity and low background value, which is often used in FIA or SIA. In virtue of its low sample consumption, high resolution efficiency, miniaturization and portability, microfluicdics has become an important trend in the future on the development of analytical instrumentation, and been applied in the fields of various biochemical analysis, coupled with FIA or SIA.Due to its highly oxidative capability, hypochlorous acid (or hypochlorite) is widely used as sewage disinfection reagent for municipal water as well as industrial bleaching agent. Meanwhile, hypochlorous acid not only plays a central role in the antimicrobial action, but also leads to localized oxidization damage at inflammatory sites when accumulated excessively. Furthermore, hypochlorous acid can also act as chemiluminescence (CL) oxidant, reacting with luminol or certain luminescent reagent.The thesis is composed of three parts:In the first chapter, the above content-related flow injection or suqential injection chemiluminescence analysis, hypochlorous acid scavenging capacity assay and antioxidant assay, have been reviewed.In the second chapter, we found that5-sulfosalicylic acid can significantly enhance the hypochlorite-luminol chemiluminescence. The enhancement mechanism, investigated by using the ultraviolet spectrum and fluorescence spectrum, proved that5-sulfosalicylic acid, once combined with exited state of luminol greatly increased the signal intensity. In this study, luminol concentration, the solutions flow rate and chemiluminescence reagent mixing parameters had been optimized. Then, the system had been applied to detect hypochlorite in tap water, swimming pool water with relatively good performance. The sample consumption was only2μL and the system will be suitable for fast analysis.In the third chapter, a sensitive μSIA-CL methodology for the determination of endogenous antioxidant scavenging capacity against hypochlorous acid under near-physiological condition is described. The effect of concentration and flow rate of CL reagents on the detective sensitivity has been optimized. The dose of hypochlorous acid was only50pmol and the scavenging reaction was effectively controlled in the time frame of several seconds, which was close to physiological conditions. The system had been applied for the determination of total antioxidant capacity of patients with relevant disease, fostering the application to screening analysis of HOC1scavenging capacity and supplementary diagnosis of HOC1-mediated diseases.