Chemistry Department, Florida Institute of Technology, 150 West University Boulevard, Melbourne, Florida 32901, United States.
Environ Sci Technol. 2011 Dec 15;45(24):10575-81. doi: 10.1021/es202237g. Epub 2011 Nov 23.
Kinetics, stoichiometry, and products of the oxidation of trimethoprim (TMP), one of the most commonly detected antibacterial agents in surface waters and municipal wastewaters, by ferrate(VI) (Fe(VI)) were determined. The pH dependent second-order rate constants of the reactions of Fe(VI) with TMP were examined using acid-base properties of Fe(VI) and TMP. The kinetics of reactions of diaminopyrimidine (DAP) and trimethoxytoluene (TMT) with Fe(VI) were also determined to understand the reactivity of Fe(VI) with TMP. Oxidation products of the reactions of Fe(VI) with TMP and DAP were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Reaction pathways of oxidation of TMP by Fe(VI) are proposed to demonstrate the cleavage of the TMP molecule to ultimately result in 3,4,5,-trimethoxybenzaldehyde and 2,4-dinitropyrimidine as among the final identified products. The oxidized products mixture exhibited no antibacterial activity against E. coli after complete consumption of TMP. Removal of TMP in the secondary effluent by Fe(VI) was achieved.
测定了最常见的地表水中和城市废水中检测到的抗菌剂甲氧苄啶（TMP）被高铁酸盐（Fe(VI)）氧化的动力学、化学计量和产物。通过 Fe(VI)和 TMP 的酸碱性质研究了 Fe(VI)与 TMP 反应的 pH 依赖性二级速率常数。还测定了二氨基嘧啶（DAP）和三甲氧基甲苯（TMT）与 Fe(VI)反应的动力学，以了解 Fe(VI)与 TMP 的反应性。通过液相色谱-串联质谱（LC-MS/MS）鉴定了 Fe(VI)与 TMP 和 DAP 反应的氧化产物。提出了 Fe(VI)氧化 TMP 的反应途径，以证明 TMP 分子的断裂，最终导致 3,4,5,-三甲氧基苯甲醛和 2,4-二硝基嘧啶作为最终鉴定的产物之一。氧化产物混合物在完全消耗 TMP 后对大肠杆菌没有抗菌活性。Fe(VI) 实现了二级出水中 TMP 的去除。
