- 學位論文
二氧化錳降解管制藥物機制之研究
Oxidative Transformation of Controlled Substances by Manganese Dioxides
摘要
近年來，民眾錯誤的用藥觀念以及藥物棄置的習慣，導致藥物進入環境水體中，使許多種藥物能夠在環境水體中檢測到微量濃度 (ng/L-μg/L)，進而對生態環境及人體健康產生潛在風險。經常使用於醫院中的管制藥物，有著鎮定、興奮、迷幻等作用，一旦進入環境中，可能會對人類及自然環境造成危害。大量存在於環境中的二氧化錳，為天然氧化物之一，其具備著高氧化力以及高吸附能力。本研究目的為探討四種管制藥物(methamphetamine、ketamine、morphine以及codeine)在環境水體中，於不同的環境因子下(pH、二氧化錳濃度、藥物初始濃度、金屬離子及腐植物質)與合成二氧化錳(δ-MnO2)之化學氧化反應之宿命研究。 實驗結果顯示，methamphetamine及ketamine有著很高的穩定性，不容易於環境水體中被MnO2降解；morphine及codeine則相對較不穩定，在中性環境(pH 7)下，morphine與100 μg/L二氧化錳經1小時後降解83%，而codeine與8 mg/L二氧化錳進行反應，經過1小時後降解65%。金屬離子(Mn2+、Fe3+、Ca2+及Mg2+)及腐磺酸會抑制morphine與二氧化錳之氧化反應；反之，腐磺酸與Fe3+反而會促進codeine與二氧化錳之氧化速率。根據動力學分析及實驗結果指出，codeine及morphine並未被二氧化錳吸附且受到於二氧化錳表面形成錯合物速率之限制而造成了二階反應。另外，當pH越低、藥物初始濃度越低或二氧化錳濃度越高，會使得此二階反應之反應速率增加。 Methamphetamine及ketamine不容易被二氧化錳氧化，在沒有其他的氧化途徑下，有可能會存在於環境當中；morphine及codeine相對來說較容易被二氧化錳氧化，在環境中可能被自然降解，但各種環境因子(pH、二氧化錳濃度、藥物初始濃度、金屬離子及腐植物質)的變動都可能影響其降解的速率。
並列摘要
Various kinds of pharmaceuticals have been observed at concentration of ng/L to μg/L level in aqueous environments in the past decade. Controlled substances have been commonly used in the hospital and can be classified as antidepressants, stimulants and hallucinogens according to their effect on central nervous system. These compounds have potential risk to humans and ecological system if entering aquatic environment. Manganese dioxides are abundant in soils and sediment as colloidal particle which have strong adsorption capacity and oxidation ability. The objective of this study is to investigate the oxidative transformation of four controlled substances (methamphetamine, ketamine, morphine and codeine) by synthesized MnO2 (δ-MnO2) in aquatic environment, studying environmental factors which could affect the oxidation rate: solution pH, manganese dioxide loading, initial drug concentration, presence of humic substance and metal ions. In the synthetic water batch experiment, methamphetamine and ketamine were stable and hardly oxidized by MnO2. Morphine and codeine were oxidized with MnO2 loading 100 μg/L and 8 mg/L at pH 7 which resulted in 85% and 65% degradation within one hour of reaction time. With addition of metal ions and fulvic acid, the oxidation of morphine was inhibited; on the contrary, ferric ion and fulvic acid enhanced the oxidation rate of codeine. Reaction can be described by second order kinetic model; results indicated that morphine and codeine were not adsorbed on MnO2 and were limited by the formation rate of surface precursor complex. Lower solution pH, lower initial drug concentration and higher MnO2 loading resulted in increasing the second order reaction rate. Methamphetamine and ketamine can be hardly oxidized by MnO2, which may be persistent in the environment if no other oxidative pathways were involved. However, morphine and codeine can be oxidized by MnO2, which indicate that they can be naturally degraded in aquatic environment. Environment factors such as pH, MnO2 loading, initial drug concentration, metal ions and humic substance can all affect the reaction rate of MnO2 oxidation for morphine and codeine.
參考文獻
延伸閱讀
- Wu, H. L. (2012). 二氧化錳對頭孢子類抗生素降解機制之研究 [master's thesis, National Taiwan University]. Airiti Library. https://doi.org/10.6342/NTU.2012.02281
- 謝旭閔（2018）。以溶膠-凝膠法製備二氧化鈰摻雜錳及其特性研究〔碩士論文，國立屏東科技大學〕。華藝線上圖書館。https://doi.org/10.6346/THE.NPUST.ME.017.2018.E06
- 宋怡葶、楊文都（2012）。製備錳氧化物及其性質研究。工程科技與教育學刊，9(3)，307-311。https://doi.org/10.6451/JETE.201209.0307
- 梁偉雁（2011）。以二氧化錳搭配次氯酸鈉及界陎活性劑去除水中異布洛芬之研究〔碩士論文，臺北醫學大學〕。華藝線上圖書館。https://doi.org/10.6831/TMU.2011.00137
- Ibrahem, M. A. (2014). Nanostructured Transition Metal Oxides and Dichalcogenides for Energy-related Applications [doctoral dissertation, National Taiwan University]. Airiti Library. https://doi.org/10.6342/NTU.2014.00355