Reaction Pathways and Kinetics of a Cyanobacterial Neurotoxin β-N-Methylamino-L-Alanine (BMAA) during Chlorination

Yi Ting Chen, Wan Ru Chen, Zhi Quan Liu, Tsair Fuh Lin

Research output: Contribution to journalArticlepeer-review

16 Citations (Scopus)

Abstract

β-N-Methylamino-L-alanine (BMAA), a probable cause of the amyotrophic lateral sclerosis/parkinsonism-dementia complex (ALS/PDC), or Alzheimer's disease, has been identified in more than 20 cyanobacterial genera. However, its removal and fate in drinking water has never been reported before. In this study, the reaction of BMAA with chlorine, a common drinking-water oxidant/disinfectant, was investigated. A liquid chromatograph coupled with a triple quadrupole mass spectrometer was employed to quantify BMAA and its intermediates. Upon chlorination, four chlorinated intermediates, each with one or two chlorines, were identified. The disappearance of BMAA caused by chlorine follows a second-order reaction, with the rate constant k1 is 5.0 × 104 M-1 s-1 at pH ∼7.0. The chlorinated intermediates were found to further react with free chlorine, exhibiting a second-order rate constant k3 = 16.8 M-1 s-1. After all free chlorine was consumed, the chlorinated intermediates autodecomposed slowly with a first order rate constant k2 = 0.003 min-1 when a reductant was added, these chlorinated intermediates were then reduced back to BMAA. The results as described shed a useful light on the reactivity, appearance, and removal of BMAA in the chlorination process of a drinking-water system.

Original languageEnglish
Pages (from-to)1303-1311
Number of pages9
JournalEnvironmental Science and Technology
Volume51
Issue number3
DOIs
Publication statusPublished - 2017 Feb 7

All Science Journal Classification (ASJC) codes

  • General Chemistry
  • Environmental Chemistry

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