Precursors and nitrogen origins of trichloronitromethane and dichloroacetonitrile during chlorination/chloramination
| Autor: | Wanhong Guo, Yongmei Liang, Qianqian Shen, Jinfeng Peng, Xin Yang |
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| Rok vydání: | 2012 |
| Předmět: |
Acetonitriles
Environmental Engineering Halogenation Nitrogen Health Toxicology and Mutagenesis chemistry.chemical_element Gas Chromatography-Mass Spectrometry chemistry.chemical_compound Hydrocarbons Chlorinated Environmental Chemistry Organic chemistry Asparagine Chloramination Pyrrole chemistry.chemical_classification Alanine Chloramines Tryptophan Public Health Environmental and Occupational Health General Medicine General Chemistry Hydrogen-Ion Concentration Pollution Amino acid chemistry Glycine Tyrosine Gas chromatography |
| Zdroj: | Chemosphere. 88:25-32 |
| ISSN: | 0045-6535 |
| DOI: | 10.1016/j.chemosphere.2012.02.035 |
| Popis: | The formation of trichloronitromethane (TCNM) and dichloroacetonitrile (DCAN) was investigated during chlorination and chloramination of 31 organic nitrogen (org-N) compounds, including amino acids, amines, dipeptides, purines, pyrimidones and pyrroles. Tryptophan and alanine generated the greatest amount of TCNM during chlorination process and asparagine and tyrosine yielded the highest amount of TCNM during chloramination process. Tryptophan, tyrosine, asparagine, and alanine produced more DCAN than other org-N compounds regardless of chlorination or chloramination. TCNM and DCAN formation was higher by chlorination than by chloramination. NH 2 Cl:org-N molar ratios, reaction time, and pH affected N-DBPs formation in varying degrees. TCNM and DCAN yields were usually high during chloramination of tyrosine, asparagine, and methylpyrrole under the following reaction conditions: NH 2 Cl:org-N molar ratios greater than 10, reaction time for 1 d, and at pH 7.2. NH 2 Cl as a major nitrogen origin in TCNM and DCAN was confirmed via labeled 15 N-monochloramine during chloramination of tyrosine, asparagine and methylpyrrole. In contrast, the majority of nitrogen in TCNM originated from glycine, and that in DCAN originated from pyrrole. Based on the intermediates identified by gas chromatography/mass spectrometry (GC/MS), a pathway scheme was proposed for TCNM and DCAN formation. |
| Databáze: | OpenAIRE |
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