| Summary: | 碩士 === 國立清華大學 === 生醫工程與環境科學系 === 98 === Abstract
2, 2’-azinobis-(3-ethylbenzothiazoline-6- sulfonate acid) radical cation (ABTS•+)
decolorization assay is one of the most widely used methods for analyzing the
antioxidant capacity（AOC） in biological and environmental samples. A separation
technique liquid chromatography combining with ABTS•+ post-column detection step
has become a useful analysis approach. In this study, we present an on-line generated
ABTS•+ as post-column with capillary electrophoresis for antioxidant capacity
analysis. Ultraviolet (UV) irradiation at 254 nm was directly photolyed colorless
ABTS to form blue-green colored ABTS•+. Furthermore, PTFE tubing coil was use to
constitute a flow-through photoreactor as an on-line direct photolysis device. This
system can simplify operating sequence and generate rapidly on-line ABTS•+ to
reduce reverse reaction. Whether purging O2 or not, about 70% production of ABTS•+
was obtained individually both in batch and on-line direct photolysis experiments.
Based on the on-line assay results, the CZE-UV/ABTS system has good precision and
post-column signal was very stable at various pHs. The system can successfully
separate five compounds and measure their antioxidant capacities simultaneously. The
migration time was smaller than 18 min and detection limitedwas about 0.58 μM
（injection sample: 84 nL）. The antioxidant capacity value of compounds shows a
good agreement with reported data. In conclusion, the CZE-UV/ABTS system is
feasible to determine the antioxidant capacity of real samples.
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