阿達瑪轉換/毛細管電泳法適用之奈米流量進樣器的開發與研究

Abstract

本研究設計一個新的奈米流量（nano-controlled）進樣器，並成功結合阿達瑪轉換法（Hadamard transform）與毛細管電泳法（capillary electrophoresis）。其中，首次利用壓克力Tee型連接頭將進樣器及毛細管電泳裝置連結。 實驗過程為將10 μL的注射針置於注射式幫浦（syringe pump）上，再NI（National Instruments）PCI-6221程式控制注射式幫浦內部之步進馬達（stepping motor）轉動步數，進一步控制進樣體積。當設定步進馬達轉動步數為750~20000步（進樣體積為1.3 nL~49.4 nL）的範圍時，具有良好的線性關係（R2 =0.9927）。本研究以核黃素（又稱維他命B2）作為分析物，並以藍光雷射（波長473 nm, 100 mW）作為激發光源。當分析物推入壓克力Tee且經電泳分離後，通過偵測窗時，由雷射激發且放出螢光，最後以光電倍增管（PMT）作偵測。在相同的進樣條件下，以阿達瑪127、255次序列分別進行實驗，訊號雜訊比可得到5.3及7.9倍的改良效果，與理論值（5.6與8）相當符合。最後，本實驗嘗試以阿達瑪127次序列進樣與毛細管線上濃縮技術進行結合，結果顯示其S/N比增加5.2倍，與理論值相當接近。 關鍵字：阿達瑪轉換／毛細管電泳法、維他命B2A novel nano-controlled sample injection device for use in Hadamard transform/capillary electrophoresis (HT/CE) was successfully developed. Instead of commercial Tee products, an acrylic-Tee connector was well designed and made in-house. Three pieces of capillaries (used for sample solution and buffer solutions, respectively) can be tightly connected together with very low dead-volume. The sample solution was placed in a syringe injector (size, 10 µL) and was pushed out by a stepping motor which was controlled by a personal computer through a NI (National Instruments) PCI-6221 device. The volume of sample injection can be well controlled and calculated based on the steps (750- ~ 20,000-steps) of the stepping motor, corresponding to the injected volume of 1.3 nL ~ 49.4 nL. A riboflavin solution and a blue diode laser (wavelength, 473 nm; 100 mW) were selected as a model compound and the light source, respectively. Compared with a conventional single injection method, the S/N ratios were substantially improved after inverse Hadamard transformation of the encoded chromatogram. Under optimized conditions, when Hadamard matrices of 127 and 255 were used, the S/N ratios of the signals for riboflavin (concentration level, 0.03 ppm) were substantially improved to 5.3- and 7.9-fold, respectively, and those improvements are in good agreement with those obtained by theory (5.6- and 8.0-fold).