利用奈米氧化鐵萃取法搭配毛細管電泳技術定量人體血漿中之多巴胺與左旋多巴

本研究利用奈米氧化鐵表面之Fe3+可與兒茶酚胺類化合物上的鄰位氧原子形成配位共價鍵之特性，針對多巴胺 (dopamine, DA) 和左旋多巴 (levodopa, LD) 進行固相萃取，並使用陽離子選擇性注入-掃集-微胞電動層析法的線上濃縮技術進行分析方法之開發。由於LD在巴金森氏症的治療中會因人體周邊酵素之影響，使其血中治療濃度不足，因此須進行劑量調整與血漿藥物濃度之監測。經最適化條件探討，將待測物與奈米氧化鐵進行吸附，經平衡時間20分鐘後進行洗滌，其後加入50 ?尳之磷酸 (0.1 M) 進行脫附，最後將樣品稀釋10倍後進行毛細管電泳法分析；沖提緩衝溶液為含25%甲醇之磷酸二氫鈉緩衝溶液 (50 mM，pH 2.5) 、高導電度緩衝溶液為150 mM 之磷酸二氫鈉緩衝溶液 (pH 2.5) 、分離緩衝溶液為含100 mM十二烷基硫酸鈉與25%甲醇之磷酸二氫鈉緩衝溶液 (50 mM，pH 2.5) ，通以10 kV電壓進行樣品注入，-20 kV電壓進行分離，並以200 nm波長偵測之。經確效後，本方法之相關係數皆大於0.990，展現良好線性關係，本法針對六位病患血漿檢體進行DA及LD之定量，其中有一位病患之血漿可偵測到DA與LD，其餘五位病患僅偵測到LD。

關鍵字

左旋多巴；奈米氧化鐵；陽離子選擇性注入-掃集-微胞電動層析法

並列摘要

Based on the coordination between surface-iron (Ⅲ) cations of iron oxide nanoparticles (IONPs) and catechol functional group of catecholamine, IONPs were used to extract dopamine (DA) and levodopa (LD). The extractant was quantified by cation selective exhaustive injection-sweeping micelle electrokinetic chromatography. LD was an important drug used in the therapy of Parkinson's disease. However, the peripheral enzyme in human body can easily metabolize LD to DA, leading to a lower drug concentration in human plasma. Therefore, dosage adjustment and therapeutic drug monitoring in patients are needed. After synthesizing, IONPs were equilibrated with analytes for 20 min. Then, 50 ?尳 phosphoric acid (0.1 M) was added for desorption. Finally, the extractant was diluted 10-fold by dd-water. The optimal conditions of CE analysis were as shown below: phosphate rinse buffer (50 mM, pH 2.5) containing 25% methanol, phosphate separation buffer (50 mM，pH 2.5) containing 25% methanol and 100 mM sodium dodecyl sulfate and high conductivity phosphate buffer (pH 2.5, 150 mM). Diluted extractant was injected at 10 kV electrokinetically. The separation was performed at -20 kV and detected at 200 nm. After method validation, calibration curves were established (r ≥ 0.990), showing good linear relationships. Six human plasma samples obtained from patients who suffered from Parkinson’s disease was analyzed. LD could be detected in all of these samples, only DA could be detected in one of them.