類黃酮化合物在毛細管電泳法之分離與線上濃縮之研究

Studies of Separation and On-line Concentration of Flavonoids in Capillary Electrophoresis

郭家銘(Chia-Ming Kuo)

指導教授 ： 林萬寅

共同指導教授 ： 林敬二(Ching-Erh Lin)

國立臺灣大學/理學院/化學研究所/博士(2012年)

https://doi.org/10.6342/NTU.2012.02044

摘要

本論文選擇以類黃酮化合物(flavonoids)以毛細管電泳法來探討偵測靈敏度的增強，注重小分子在毛細管電泳上之線上濃縮技巧。結果分為兩大部分：
第一部份先以毛細管區帶電泳法(CZE)及微胞電動力層析法(MEKC)做分離，接著測試幾種不同堆積模式，包括電極極性反向堆積模式(large volume sample stacking with reverse electrode polarity, LVSS)及大體積反向電壓微胞掃集模式(large volume sample stacking-sweeping, LVSS-sweeping)或正向添加SDS的掃集模式，其中LVSS-Sweeping及正向掃集的最佳化條件較難求得，而LVSS法於0.4 分鐘時切換電壓方向可得良好的堆積，並測得hesperetin、naringenin、quercetin與kaempferol的偵測極限分別14.87、14.71、19.76與16.66 ng/mL(S/N = 3)，並可用於真實樣品偵測。
第二部份強調於逆向掃集模式的改良，最佳條件為使用掃集模式(sweeping)，於分離緩衝中及樣品基質中添加適當電解質，有助改善長時間進樣的樣品濃縮。甚至可讓注入類黃酮化合物時間達480秒，最大樣品體積約佔毛細管總長的96.5 %。樣品基質使用pH 2.0的20 mM磷酸鹽緩衝液，分離緩衝液為pH 2.0的20 mM樣品注入時間為120秒時，磷酸緩衝液並分別添加50 mM的SDS，ACN則分別添加10 %。而120秒的樣品注入所得hesperetin、naringenin、quercetin及kaempferol之偵測極限分別為43.53、38.25、57.38及48.55 ng/mL(S/N = 3)。而480秒的樣品注入所得hesperetin、naringenin、quercetin及kaempferol之偵測極限分別為21.28、15.37、24.26及24.7 ng/mL(S/N = 3)。並能有效應用於真實樣品之檢測。

關鍵字

類黃酮化合物 ； 毛細管電泳 ； 線上濃縮 ； 樣品掃集 ； 大體積堆積

並列摘要

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.

並列關鍵字

flavonoids ； capillary electrophoresis ； on-line concentration ； sweeping ； large volume sample stacking

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