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Tekle-Röttering A, Reisz E, Jewell KS, Lutze HV, Ternes TA, Schmidt W, Schmidt TC. Ozonation of pyridine and other N-heterocyclic aromatic compounds: Kinetics, stoichiometry, identification of products and elucidation of pathways. WATER RESEARCH 2016; 102:582-593. [PMID: 27448509 DOI: 10.1016/j.watres.2016.06.021] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Revised: 06/08/2016] [Accepted: 06/10/2016] [Indexed: 05/06/2023]
Abstract
Pyridine, pyridazine, pyrimidine and pyrazine were investigated in their reaction with ozone. These compounds are archetypes for heterocyclic aromatic amines, a structural unit that is often present in pharmaceuticals, pesticides and dyestuffs (e.g., enoxacin, pyrazineamide or pyrimethamine). The investigated target compounds react with ozone with rate constants ranging from 0.37 to 57 M(-1) s(-1), hampering their degradation during ozonation. In OH radical scavenged systems the reaction of ozone with pyridine and pyridazine is characterized by high transformation (per ozone consumed) of 55 and 54%, respectively. In non scavenged system the transformation drops to 52 and 12%, respectively. However, in the reaction of pyrimidine and pyrazine with ozone this is reversed. Here, in an OH radical scavenged system the compound transformation is much lower (2.1 and 14%, respectively) than in non scavenged one (22 and 25%, respectively). This is confirmed by corresponding high N-oxide formation in the ozonation of pyridine and pyridazine, but probably low formation in the reaction of pyrimidine and pyrazine with ozone. With respect to reaction mechanisms, it is suggested that ozone adduct formation at nitrogen is the primary step in the ozonation of pyridine and pyridazine. On the contrary, ozone adduct formation to the aromatic ring seems to occur especially in the ozonation of pyrimidine as inferred from hydrogen peroxide yield. However, also OH radical reactions are supposed processes in the case of pyrimidine and in particular for pyrazine, albeit negligible OH radical yields are obtained. The low compound transformation in OH radical scavenged system can prove this. As a result of negligible OH radical yields in all cases (less than 6%) electron transfer as primary reaction pathway plays a subordinate role.
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Affiliation(s)
- Agnes Tekle-Röttering
- University of Duisburg-Essen, Faculty of Chemistry, Instrumental Analytical Chemistry, Universitätsstraße 5, 45141 Essen, Germany; Westphalian University of Applied Sciences, Department of Environmental Engineering, Neidenburgerstraße 10, 45897 Gelsenkirchen, Germany
| | - Erika Reisz
- University "Politehnica" of Timişoara, Faculty of Industrial Chemistry and Environmental Engineering, Bulevardul Vasile Pârvan Nr. 6, 300233 Timişoara, Romania
| | - Kevin S Jewell
- Federal Institute of Hydrology (BfG), Am Mainzer Tor 1, 56068 Koblenz, Germany
| | - Holger V Lutze
- University of Duisburg-Essen, Faculty of Chemistry, Instrumental Analytical Chemistry, Universitätsstraße 5, 45141 Essen, Germany; Centre for Water and Environmental Research (ZWU), University of Duisburg-Essen, Universitätsstraße 2, 45141 Essen, Germany; IWW Water Centre, Moritzstraße 26, 45476 Mülheim an der Ruhr, Germany
| | - Thomas A Ternes
- Federal Institute of Hydrology (BfG), Am Mainzer Tor 1, 56068 Koblenz, Germany
| | - Winfried Schmidt
- Westphalian University of Applied Sciences, Department of Environmental Engineering, Neidenburgerstraße 10, 45897 Gelsenkirchen, Germany; Centre for Water and Environmental Research (ZWU), University of Duisburg-Essen, Universitätsstraße 2, 45141 Essen, Germany
| | - Torsten C Schmidt
- University of Duisburg-Essen, Faculty of Chemistry, Instrumental Analytical Chemistry, Universitätsstraße 5, 45141 Essen, Germany; Centre for Water and Environmental Research (ZWU), University of Duisburg-Essen, Universitätsstraße 2, 45141 Essen, Germany; IWW Water Centre, Moritzstraße 26, 45476 Mülheim an der Ruhr, Germany.
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Tekle-Röttering A, Jewell KS, Reisz E, Lutze HV, Ternes TA, Schmidt W, Schmidt TC. Ozonation of piperidine, piperazine and morpholine: Kinetics, stoichiometry, product formation and mechanistic considerations. WATER RESEARCH 2016; 88:960-971. [PMID: 26624229 DOI: 10.1016/j.watres.2015.11.027] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 11/06/2015] [Accepted: 11/08/2015] [Indexed: 06/05/2023]
Abstract
Piperidine, piperazine and morpholine as archetypes for secondary heterocyclic amines, a structural unit that is often present in pharmaceuticals (e.g., ritalin, cetirizine, timolol, ciprofloxacin) were investigated in their reaction with ozone. In principle the investigated compounds can be degraded with ozone in a reasonable time, based on their high reaction rate constants with respect to ozone (1.9 × 10(4)-2.4 × 10(5) M(-1) s(-1)). However, transformation is insufficient (13-16%), most likely due to a chain reaction, which decomposes ozone. This conclusion is based on OH scavenging experiments, leading to increased compound transformation (18-27%). The investigated target compounds are similar in their kinetic and stoichiometric characteristics. However, the mechanistic considerations based on product formation indicate various reaction pathways. Piperidine reacts with ozone via a nonradical addition reaction to N-hydroxypiperidine (yield: 92% with and 94% without scavenging, with respect to compound transformation). However, piperazine degradation with ozone does not lead to N-hydroxypiperazine. In the morpholine/ozone reaction, N-hydroxymorpholine was identified. Additional oxidation pathways in all cases involved the formation of OH with high yields. One important pathway of piperazine and morpholine by ozonation could be the formation of C-centered radicals after ozone or OH radical attack. Subsequently, O2 addition forms unstable peroxyl radicals, which in one pathway loose superoxide radicals by generating a carbon-centered cation. Subsequent hydrolysis of the carbon-centered cation leads to formaldehyde, whereby ozonation of the N-hydroxy products can proceed in the same way and in addition give rise to hydroxylamine. A second pathway of the short-lived peroxyl radicals could be a dimerization to form short-lived tetraoxides, which cleave by forming hydrogen peroxide. All three products have been found.
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Affiliation(s)
- Agnes Tekle-Röttering
- University of Duisburg-Essen, Faculty of Chemistry, Instrumental Analytical Chemistry, Universitätsstraße 5, 45141, Essen, Germany; Westphalian University of Applied Sciences, Department of Environmental Engineering, Neidenburgerstraße 10, 45897, Gelsenkirchen, Germany
| | - Kevin S Jewell
- Federal Institute of Hydrology (BfG), Am Mainzer Tor 1, 56068, Koblenz, Germany
| | - Erika Reisz
- University "Politehnica" of Timişoara, Faculty of Industrial Chemistry and Environmental Engineering, Bulevardul Vasile Pârvan Nr. 6, 300233, Timişoara, Romania
| | - Holger V Lutze
- University of Duisburg-Essen, Faculty of Chemistry, Instrumental Analytical Chemistry, Universitätsstraße 5, 45141, Essen, Germany; Centre for Water and Environmental Research (ZWU), University of Duisburg-Essen, Universitätsstraße 2, 45141, Essen, Germany
| | - Thomas A Ternes
- Federal Institute of Hydrology (BfG), Am Mainzer Tor 1, 56068, Koblenz, Germany
| | - Winfried Schmidt
- Westphalian University of Applied Sciences, Department of Environmental Engineering, Neidenburgerstraße 10, 45897, Gelsenkirchen, Germany; Centre for Water and Environmental Research (ZWU), University of Duisburg-Essen, Universitätsstraße 2, 45141, Essen, Germany
| | - Torsten C Schmidt
- University of Duisburg-Essen, Faculty of Chemistry, Instrumental Analytical Chemistry, Universitätsstraße 5, 45141, Essen, Germany; Centre for Water and Environmental Research (ZWU), University of Duisburg-Essen, Universitätsstraße 2, 45141, Essen, Germany.
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Awad MI, Mohammad AM, Ohsaka T. Electroanalysis of a Ternary Disinfectant Mixture. ANAL LETT 2012. [DOI: 10.1080/00032719.2012.675497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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