Aqueous chlorination of mefenamic acid: Kinetics, transformation by-products and ecotoxicity assessment
Mefenamic acid (Mfe) is one of the most frequently detected nonsteroidal anti-inflammatory drugs in the environment. This study investigated the kinetics and the transformation by-products of Mfe during aqueous chlorination. The potential ecotoxicity of the transformation by-products was also evalua...
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| Format: | Article |
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Royal Society of Chemistry
2016
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| author | Khalit, W.N.A.W. Tay, K.S. |
| author_facet | Khalit, W.N.A.W. Tay, K.S. |
| author_sort | Khalit, W.N.A.W. |
| collection | UM |
| description | Mefenamic acid (Mfe) is one of the most frequently detected nonsteroidal anti-inflammatory drugs in the environment. This study investigated the kinetics and the transformation by-products of Mfe during aqueous chlorination. The potential ecotoxicity of the transformation by-products was also evaluated. In the kinetic study, the second-order rate constant (kapp) for the reaction between Mfe and free available chlorine (FAC) was determined at 25 ± 0.1 °C. The result indicated that the degradation of Mfe by FAC is highly pH-dependent. When the pH was increased from 6 to 8, it was found that the kapp for the reaction between Mfe and FAC was decreased from 16.44 to 4.4 M-1 s-1. Characterization of the transformation by-products formed during the chlorination of Mfe was carried out using liquid chromatography-quadrupole time-of-flight accurate mass spectrometry. Four major transformation by-products were identified. These transformation by-products were mainly formed through hydroxylation, chlorination and oxidation reactions. Ecotoxicity assessment revealed that transformation by-products, particularly monohydroxylated Mfe which is more toxic than Mfe, can be formed during aqueous chlorination. |
| first_indexed | 2024-03-06T05:44:20Z |
| format | Article |
| id | um.eprints-18064 |
| institution | Universiti Malaya |
| last_indexed | 2024-03-06T05:44:20Z |
| publishDate | 2016 |
| publisher | Royal Society of Chemistry |
| record_format | dspace |
| spelling | um.eprints-180642017-10-23T06:15:10Z http://eprints.um.edu.my/18064/ Aqueous chlorination of mefenamic acid: Kinetics, transformation by-products and ecotoxicity assessment Khalit, W.N.A.W. Tay, K.S. QD Chemistry Mefenamic acid (Mfe) is one of the most frequently detected nonsteroidal anti-inflammatory drugs in the environment. This study investigated the kinetics and the transformation by-products of Mfe during aqueous chlorination. The potential ecotoxicity of the transformation by-products was also evaluated. In the kinetic study, the second-order rate constant (kapp) for the reaction between Mfe and free available chlorine (FAC) was determined at 25 ± 0.1 °C. The result indicated that the degradation of Mfe by FAC is highly pH-dependent. When the pH was increased from 6 to 8, it was found that the kapp for the reaction between Mfe and FAC was decreased from 16.44 to 4.4 M-1 s-1. Characterization of the transformation by-products formed during the chlorination of Mfe was carried out using liquid chromatography-quadrupole time-of-flight accurate mass spectrometry. Four major transformation by-products were identified. These transformation by-products were mainly formed through hydroxylation, chlorination and oxidation reactions. Ecotoxicity assessment revealed that transformation by-products, particularly monohydroxylated Mfe which is more toxic than Mfe, can be formed during aqueous chlorination. Royal Society of Chemistry 2016 Article PeerReviewed Khalit, W.N.A.W. and Tay, K.S. (2016) Aqueous chlorination of mefenamic acid: Kinetics, transformation by-products and ecotoxicity assessment. Environmental Science: Processes and Impacts, 18 (5). pp. 555-561. ISSN 2050-7887, DOI https://doi.org/10.1039/c6em00017g <https://doi.org/10.1039/c6em00017g>. http://dx.doi.org/10.1039/c6em00017g doi:10.1039/c6em00017g |
| spellingShingle | QD Chemistry Khalit, W.N.A.W. Tay, K.S. Aqueous chlorination of mefenamic acid: Kinetics, transformation by-products and ecotoxicity assessment |
| title | Aqueous chlorination of mefenamic acid: Kinetics, transformation by-products and ecotoxicity assessment |
| title_full | Aqueous chlorination of mefenamic acid: Kinetics, transformation by-products and ecotoxicity assessment |
| title_fullStr | Aqueous chlorination of mefenamic acid: Kinetics, transformation by-products and ecotoxicity assessment |
| title_full_unstemmed | Aqueous chlorination of mefenamic acid: Kinetics, transformation by-products and ecotoxicity assessment |
| title_short | Aqueous chlorination of mefenamic acid: Kinetics, transformation by-products and ecotoxicity assessment |
| title_sort | aqueous chlorination of mefenamic acid kinetics transformation by products and ecotoxicity assessment |
| topic | QD Chemistry |
| work_keys_str_mv | AT khalitwnaw aqueouschlorinationofmefenamicacidkineticstransformationbyproductsandecotoxicityassessment AT tayks aqueouschlorinationofmefenamicacidkineticstransformationbyproductsandecotoxicityassessment |