Studies of Separation and On-line Concentration of Flavonoids in Capillary Electrophoresis
Date Issued
2012
Date
2012
Author(s)
Kuo, Chia-Ming
Abstract
In this dissertation, four flavonoid analytes were selected to investigate the enhancement of detection sensitivity by capillary electrophoresis. Several on-line concentration modes studied were divided into two parts:
In the first part, CZE and MEKC modes were studied first, and then the large volume stacking with switching the electrode polarity (LVSS) mode and the LVSS-sweeping mode were used to concentrate the anlaytes. Amoung these modes, the LVSS with switching polarity at 0.4 min was the optimal condition. The limits of detections (S/N = 3) of hesperetin、naringenin、quercetin and kaempferol were determined to be 14.87、14.71、19.76 and 16.66 ng/mL, respectively.
In the second part, the sweeping technique was improved to concentrate the analytes. With 120 sec sample injection, the concentration of phosphate buffer at 20 mM was used as the sample matrix, while the separation buffer consisting of 20 mM phosphate electrolyte and 50 mM SDS and 10 % acetonitrile at pH 2.0 was optimized, and the limits of detections (S/N = 3) of hesperetin、naringenin、quercetin and kaempferol were determined to be 43.53、38.25、57.38 and 48.55 ng/mL, respectively. Sample injection up to 480 sec can also be achieved for baseline separation of four flavonoids in the sweeping mode, and the limits of detections (S/N = 3) of hesperetin、naringenin、quercetin and kaempferol were determined to be 21.28、15.37、24.26 and 24.7 ng/mL, respectively. The method was successfully applied to determine flavonoids in several real samples.
Subjects
flavonoids
capillary electrophoresis
on-line concentration
sweeping
large volume sample stacking
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-101-D96223109-1.pdf
Size
23.32 KB
Format
Adobe PDF
Checksum
(MD5):0123e57d9a59de0a157199c010edbf82