Nitrogenous disinfection byproducts formation and nitrogen origin exploration during chloramination of nitrogenous organic compounds.
Formation of nitrogenous disinfection by-products (N-DBPs) of cyanogen chloride (CNCl), dichloroacetonitrile (DCAN) and chloropicrin was evaluated during chloramination of several selected groups of nitrogenous organic (organic-N) compounds, including alpha-amino acids, amines, dipeptides, purines, and pyrimidines, The intermediates generated, reaction pathways, and nitrogen origin in N-DBPs were explored as well. CNCl was observed in chloramination of all tested organic-N compounds, with glycine giving the highest yields. DCAN was formed during chloramination of glutamic acid, cytosine, cysteine, and tryptophan. Chloramination of most organic-N compounds except for cysteine and glutamic acid generated chloropicrin. Aldehydes and nitriles were identified as the intermediates by negative mode electrospray ionization mass spectrometry during reactions of NH(2)Cl and organic-N compounds. Labeled (15)N-monochloramine ((15)NH(2)Cl) techniques showed that nitrogen in N-DBPs may originate from both NH(2)Cl and organic-N compounds and the nitrogen partition percentages vary as functions of reactants and pH.
Yang
Xin
X
Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China. xinyang@ust.hk
Fan
Chihhao
C
Shang
Chii
C
Zhao
Quan
Q
D000097:Acetonitriles / Q000032:analysis / Q000737:chemistry; D002700:Chloramines / Q000737:chemistry; D003486:Cyanides / Q000032:analysis / Q000737:chemistry; D004203:Disinfection / Q000379:methods*; D006843:Hydrocarbons, Chlorinated / Q000032:analysis / Q000737:chemistry; D009584:Nitrogen / Q000737:chemistry*
D000097:Acetonitriles; D002700:Chloramines; D003486:Cyanides; D006843:Hydrocarbons, Chlorinated; C014430:cyanogen chloride; C100187:chloropicrin; C030816:chloramine; D009584:Nitrogen; C051716:dichloroacetonitrile