利用毛細管電泳/間接紫外光偵測法分析幾丁寡醣與尿液中之硫二乙酸與乙醇酸

Abstract

本研究利用毛細管電泳結合間接紫外光偵測法，可快速分析一些不具有發色團的分析物，此方法是於背景電解質溶液中，加入能夠吸收紫外光的共競離子，當分析物區帶通過偵測器，會取代背景電解質溶液中部份帶有相同電性的共競離子，使局部區域內共競離子的濃度降低，因此降低紫外光吸收訊號值，產生一負向的分析波峰。毛細管電泳/間接紫外光偵測法具有分離效率高、再現性良好、自動化儀器操作簡便、分析樣品及電解質溶液消耗量少等優點，且分析樣品不需經由複雜繁瑣的化學衍生化過程，即可直接分析。 利用毛細管電泳結合間接紫外光偵測法檢測幾丁寡醣(DP=1~6)時，選擇1,3-二氮唑為共競離子，分離時間僅需5分鐘，分析物移動時間的標準偏差在0.60 %以下，檢量線的相關係數皆大於0.996，其偵測極限最低可達0.45 mg/L，並可利用此方法推測未知幾丁寡醣的分子量。 毛細管電泳結合間接紫外光偵測尿液中的代謝物－硫二乙酸和乙醇酸，選擇1,2,4-苯三甲酸為共競離子，於背景電解質溶液中加入二乙烯三胺作為電滲流修飾劑，分離時間僅需7分鐘，分析物移動時間的標準偏差 0.19%以下，其偵測極限分別為0.24和0.57 mg/L回收率則在93.39 % ~ 101.20 %之間。 綜合上述，利用毛細管電泳結合間接紫外光偵測法，應用於幾丁寡醣與尿液中的代謝物－硫二乙酸和乙醇酸的分析，可得到良好的分析結果，並將此方法應用於實際樣品之定性與定量分析。

In this study, analytes that do not absorb in the UV/Vis region can be detected by capillary electrophoresis with indirect UV. The light-absorbing co-ion provides a background signal. The background signal decreases as the analyte’s zone passing through the detector. The separation of analytes by capillary electrophoresis with indirect UV offers several advantages such as high separation performance, good reproducibility, easily manipulation, minute sample consumption, and avoiding complicated derivatization process. Six chitooligosaccharides (DP=1~6) were separated in five minutes by capillary electrophoresis with indirect UV using imidazole as the co-ion. The RSD of the migration time is under 0.60%. The correlation coefficient of the calibration curve is above 0.996 and the detection limit is 0.45 mg/L. Thiodiglycolic acid and glycolic acid were analyzed by capillary electrophoresis with indirect UV within seven minutes. BTC was the co-ion. DETA was selected as the EOF modifier. The migration times’ RSDs were under 0.19%. The detection limits of urinary thiodiglycolic acid and glycolic acid were 0.24 and 0.57 mg/L, respectively. The recovery were between 93.3% ~ 101.20%. This method can be applied to analyze urinary sample after suitable sample pretreatment.