title: A novel assay to measure tertiary and quaternary amines in wastewater: An indicator for NDMA wastewater precursors.
abstract: This study examined the potential of using a novel bulk amine assay as an approximation for the tertiary and quaternary amine load in wastewaters and surface water samples, and this approximation was compared to N-nitrosodimethylamine (NDMA) formation potential using chloramines. An existing colorimetric method was examined and optimized for the detection of amines in environmental water samples. The method consists of liquid-liquid extraction followed by a catalyzed reaction to form a yet-undefined product that is known to be both a strong chromophore and fluorophore. Previous work verified that this reaction was effectively catalyzed by a number of compounds containing tertiary and quaternary amine moieties. Many tertiary and quaternary compounds are also efficient producers of NDMA under chloramination conditions, and a linear correlation was consequently derived from the bulk amine signals vs. NDMA formation potential in various wastewater samples (R2= 0.74; n = 24; p-value < 0.05). The results provide evidence that approximately 2% of the tertiary and quaternary amines measured can form NDMA and an estimated 0.01-1.3% of nitrogen in dissolved organic nitrogen originates from these bulk amines. The normalization of NDMA concentration by the amine measurement revealed that ozone effectively destroyed those tertiary and quaternary amine structures more likely to form NDMA in treated wastewater samples. This bulk amine assay illustrates that proxy measurements of tertiary and quaternary amines can be linked to the NDMA formation potential of a given sample, and this approach may prove useful as a characterizing tool for NDMA precursors in wastewater.
authors.affiliation: Southern Nevada Water Authority, P.O. Box 99954, Las Vegas, NV, 89193-9954, USA. Electronic address: gwen.woods-chabane@hdrinc.com.
authors.forename: Gwen C
authors.initials: GC
authors.lastname: Woods-Chabane
authors.affiliation: Southern Nevada Water Authority, P.O. Box 99954, Las Vegas, NV, 89193-9954, USA.
authors.forename: Caitlin M
authors.initials: CM
authors.lastname: Glover
authors.affiliation: Southern Nevada Water Authority, P.O. Box 99954, Las Vegas, NV, 89193-9954, USA.
authors.forename: Erica J
authors.initials: EJ
authors.lastname: Marti
authors.affiliation: Southern Nevada Water Authority, P.O. Box 99954, Las Vegas, NV, 89193-9954, USA. Electronic address: eric.dickenson@snwa.com.
authors.forename: Eric R V
authors.initials: ERV
authors.lastname: Dickenson
mesh_terms: D000588:Amines / Q000032:analysis* / Q000737:chemistry; D002384:Catalysis; D002700:Chloramines / Q000737:chemistry; D004128:Dimethylnitrosamine / Q000737:chemistry*; D059625:Liquid-Liquid Extraction; D008722:Methods; D010126:Ozone / Q000737:chemistry; D062065:Wastewater / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D000588:Amines; D002700:Chloramines; D004128:Dimethylnitrosamine; D010126:Ozone; D062065:Wastewater
keywords: Amine assay; Disinfection by-product; N-nitrosodimethylamine; NDMA precursors; Quaternary amines; Tertiary amines