1072-67-9Relevant articles and documents
Insight into sulfamethoxazole degradation, mechanism, and pathways by AgBr-BaMoO4 composite photocatalyst
Ray, Schindra Kumar,Dhakal, Dipesh,Lee, Soo Wohn
, p. 686 - 695 (2018)
A composite photocatalyst, AgBr-BaMoO4 was fabricated by two step method; microwave hydrothermal and precipitation-deposition. The as prepared photocatalyst samples were characterized by various techniques. The facet coupling was seen between the (204) plane of BaMoO4 and (200)/(222) planes of AgBr on the basis of XRD/HRTEM analysis. The pharmaceutical pollutant, sulfamethoxazole was adopted to investigate the photocatalytic performances of samples under UV–vis irradiation. The AgBr-BaMoO4 composite degraded the aqueous sulfamethoxazole drug in UV–vis light about 64% within 75 min, which was attributed to efficient separation of photogenerated electron–hole pairs across the interface between Ag/AgBr and BaMoO4. The multi-electron induced oxygen reduced reaction (ORR) was observed. The radical trapping experiment indicates that OH? has major role for sulfamethoxazole degradation. The four successive photodegradation of sulfamethoxazole in UV–vis light indicates the stability of composite photocatalyst. Furthermore, the three different degradation pathways were designed on the basis of retention time and molecular masses of 18 degraded organic fragments that was confirmed by high-performance liquid chromatography photodiode array (HPLC-PDA) and high resolution-quadruple time of flight electrospray ionization mass spectroscopy (HR-QTOF ESI/MS) techniques. The total organic carbon (TOC) analysis suggested the mineralization of SMZ by composite photocatalyst. This study not only demonstrates the enhancement of photocatalytic performance of wide band gap semiconductor by making composite with narrow band gap semiconductor but also detail degradation pathways and mechanisms of sulfamethoxazole.
Transformation of the antibacterial agent sulfamethoxazole in reactions with chlorine: Kinetics, mechanisms, and pathways
Dodd, Michael C.,Huang, Ching-Hua
, p. 5607 - 5615 (2004)
Sulfamethoxazole (SMX) - a member of the sulfonamide antibacterial class - has beenfrequently detected in municipal wastewater and surface water bodies in recent years. Kinetics, mechanisms, and products of SMX in reactions with free chlorine (HOCl/OCl-) were studied in detail to evaluate the effect of chlorination processes on the fate of sulfonamides in municipal wastewaters and affected drinking waters. Direct reactions of free available chlorine (FAC) with SMX were quite rapid. A half-life of 23 s was measured under pseudo-first-order conditions ([FAC]0 = 20 μM (1.4 mg/L) and [SMX]0 = 2 μM) at pH 7 and 25°C in buffered reagent water. In contrast, a half-life of 38 h was determined for reactions with combined chlorine (NH2Cl, NHCl2) under similar conditions. Free chlorine reaction rates were first-order in both substrate and oxidant, with specific second-order rate constants of 1.1 × 103 and 2.4 × 103 M -1 s-1 for SMX neutral and anionic species, respectively. Investigations with substructure model compounds and identification of reaction products verified that chlorine directly attacks the SMX aniline-nitrogen, resulting in (i) halogenation of the SMX aniline moiety to yield a ring-chlorinated product at sub-stoichiometric FAC concentrations (i.e., [FAC]0:[SMX]0 ≤ 1) or (ii) rupture of the SMX sulfonamide moiety in the presence of stoichiometric excess of FAC to yield 3-amino-5-methylisoxazole, SO42- (via SO2), and N-chloro-p-benzoquinoneimine. Reaction ii represents an unexpected aromatic amine chlorination mechanism that has not previously been evaluated in great detail. Experiments conducted in wastewater and drinking water matrixes appeared to validate measured reaction kinetics for SMX, indicating that SMX and likely other sulfonamide antibacterials should generally undergo substantial transformation during disinfection of such waters with free chlorine residuals.
Preparation method 3 -amino -5 -alkyl isoxazole
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Paragraph 0024-0025; 0028; 0029-0030; 0033, (2020/06/05)
The invention discloses a preparation method of 3-amino-5-alkyl isoxazole, realizes preparation through two steps and belongs to the technical field of organic chemistry. By starting from easily obtained aldehyde, after the addition with acetonitrile under the existence of metal alkali, an intermediate of hydroxy nitrile is obtained; then, the hydroxy nitrile reacts with hydroxylamine; ring closing reaction is performed under the existence of Lewis acid; after autoxidation, the 3-amino-5-alkyl isoxazole is obtained. The raw materials in the reaction process are very commons; chloroform or tetrachloromethane in a traditional method is avoided; potential industrial amplification prospects are realized.
Insights into the electrochemical degradation of sulfamethoxazole and its metabolite by Ti/SnO2-Sb/Er-PbO2 anode
Wang, Yanping,Zhou, Chengzhi,Wu, Jinhua,Niu, Junfeng
supporting information, p. 2673 - 2677 (2020/06/01)
Electrochemical degradation of sulfamethoxazole (SMX) and its metabolite acetyl-sulfamethoxazole (Ac-SMX) by Ti/SnO2-Sb/Er-PbO2 were investigated. Results indicated that the electrochemical degradation of SMX and Ac-SMX followed pseu
