| 摘要註: |
在過去幾年中，由於掌性化合物的生物活性對生活的影響，因此掌性化合物的分析技術有了高度的需求。毛細管電泳（CE）在化學分析上是一種多功能的平台。線上濃縮技巧的導入提供了CE搭配傳統的UV檢測器在分析濃度為ppb級的胺基酸有快速、高靈敏的分離優點。本研究在毛細管區帶電泳（CZE）系統搭配反向電極極性堆積模式（REPSM）進行線上濃縮與分離11個胺基酸（D,L-白胺酸，D,L-天門冬胺酸，D,L-谷胺酸，D,L-脯胺酸，D,L-丙胺酸，甘胺酸）。實驗分別對四種環糊精(cyclodextrin, CD)的衍生物:2 - 羥丙基-β-環糊精（HP-β-CD），和氨基-α、β與γ-環糊精進行了掌性選擇能力的探討。 實驗結果顯示毛細管電泳電解質中必須同時添加β-CD與SDS才具有分離白胺酸，天門冬胺酸與谷胺酸的效果。而NH2-β-CD則是單獨就能分離所有的目標胺基酸。在CZE最佳化分離條件搭配REPSM線上濃縮的操作參數(時使用注射壓力9.0 psi連續20.0秒和20.0千伏的分離電壓)時。檢量線濃度範圍可從0.05－1.25 ppm，最低偵測極限分別在8.0－22.0 ppb的範圍內。在真實樣品的分析方面，果汁樣品中胺基酸分析必須先經過前處理步驟。樣品前處理步驟中，果汁首先由C18固相萃取管柱進行潔淨。 接下來，胺基酸衍生上FMOC，最後 果汁內胺基酸含量由CZE-REPSM進行定量分析。定量分析測定的結果與反相高效液相層析儀比較，以驗證本論文分析方法發展的準確性。 Enantioselective analytical techniques have been highly demanded in the last years due to the well-known relevance of chirality in the biological activity of compounds. Capillary electrophoresis (CE) represents a versatile platform for chemical analysis. In this thesis, on-line preconcentration was developed for rapid, sensitive, and enantioselective analysis of ppb levels of amino acids by CE with conventional UV detection. The reverse electrode polarity stacking mode (REPSM) was used for the on-line concentration of eleven amino acids (D,L-Leucine, D,L-Aspartic acid, D,L-Glutamine acid, D,L-proline, D,L- Alanine and Glycine) by capillary zone electrophoresis (CZE) were investigated. Four cyclodextrins (CD): 2-hydroxypropyl-β-CD (HP-β-CD), amino-α-CD, amino-β-CD, and amino-γ-CD -were also investigated their chiral separation capability.Results shown that running electrolyte constitute with β-CD and SDS, only separated for D,L-Leucine, D,L-Aspartic acid, and D,L-Glutamine. However,, amino -β-CD separated well for all D,L-amino acids. The optimized conditions were obtained with CZE using REPSM (with injection 9.0 psi 20.0 sec and separation voltage operated at 20.0 kV). Working concentration from 0.05 to 1.25 ppm was achieved and the detection limits were within in the range of 0.008-0.022 ppm.For real amino acids sample analysis, juice sample was clean and derivatived preciously. In sample pretreatment steps, amino acids were derivatived using 9-fluorenylmethyl-chloroformate (FMOC-Cl) and then cleanup by C18 solid phase extraction (SPE) cartridge. The concentrations of amino acids in juice were determined by CZE-REPSM. Also, the reversed-phase high-performance liquid chromatography (RP-HPLC) was employed as a reference method to compare the amino acids analysis results from CE. |