Ketamine是近年來極為熱門的濫用藥物，由於其無色無味，加入飲料中不易被察覺，不僅如此，還會造成飲用者產生暫時性失憶，因此成為不肖人士新的犯罪手法。
此種新興藥物雖然有便利的免疫試劑可提供檢測，但其檢驗成本較為昂貴，因此，本實驗以電化學偵測法與濃縮技術對Ketamine進行檢測分析之相關探討，期望能建立更為迅速、靈敏的方法，以利於提升預防犯罪與自我保護的能力等。
本研究主要是利用甲基丙烯酸(methacrylic acid, MAA)為單體、乙二醇二甲基丙烯酸酯(ethylene glycol dimethylacrylate, EGDMA)為交聯劑、2,2-偶氮異二丁腈(2,2’-Azobis-isobutyronitrile, AIBN)為起始劑，於順磁性粒子(magnetic beads)表面進行聚合反應，形成聚(甲基丙烯酸-乙二醇二甲基丙烯酸酯)修飾微粒。
因甲基丙烯酸含有羧基，與Ketamine產生分子間氫鍵，使修飾矽磁微粒可有效吸附Ketamine，以其對含有Ketamine溶液進行固相微萃取(solid-phase microextractio, SPME)，再以醋酸銨甲醇混合溶液進行脫附，分別測定經由poly(MAA-EGDMA)修飾微粒萃取後的上清液與其脫附液之Ketamine濃度，以評估修飾微粒之吸附效率，證明其具有良好的濃縮效果。
本研究以經電化學活化之玻璃碳電極(glassy carbon electrode, GCE)於流動注入分析系統對Ketamine進行偵測，探討工作電極電位與載流液流速對Ketamine之訊號偵測影響。在最佳條件下，偵測Ketamine的線性範圍在0.5μM到100μM。
以poly(MAA-EGDMA)修飾微粒吸附樣品中Ketamine，再以少量溶液進行脫附，這樣不僅可達到濃縮目的，及大大降低樣品中Ketamine含量測定的偵測極限，並且助於減少基質的干擾，以達一個便利、迅速、靈敏的分析方法。 Ketamine (2-(2-chlorophenyl)-2-methylamino-cyclohexanone) was used for anaesthesia originally but has emerged as an abused drug in recent years.
The prevalence of ketamine abuse demands a direct and rapid determination method. Poly (methacrylic acid-ethylene glycol dimethacrylate, MAA-EGDMA) magnetic beads were used for the solid-phase microextraction (SPME) of ketamine.
As to poly (methacrylic acid–ethylene glycol dimethacrylate, MAA-EGDMA), its hydrophobic main chains and acidic pendant groups make it a superior material for extraction of basic analytes from aqueous matrix.
And the results indicated that the adsorption process of the target analytes was involved with hydrophobic interaction and ion-exchange interaction.
Therefore, coupled the solid-phase microextraction (SPME) to flow injection analysis (FIA) with electrochemical analyzer, the SPME method was successfully applied for the determination of ketamine.
Under the optimized conditions, ketamine was determined directly from poly(MAA-EGDMA) magnetic beads in a good dynamic linear range between 0.5uM to 100uM, with the detection limit obtained as 0.3uM.
To compare these results with that of coupling SPME to HPLC, the modified magnetic beads can effectively adsorbe ketamine.
