title: The effect of natural organic matter polarity and molecular weight on NDMA formation from two antibiotics containing dimethylamine functional groups.
abstract: N-nitrosodimethylamine (NDMA) is a disinfection byproduct preferentially formed in chloraminated water. NDMA may be formed from certain chemicals containing dimethylamine (DMA) functional groups. This reaction may be slowed by the presence of natural organic matter (NOM). In this study, NOM fractionated by size or polarity was tested for its ability to slow or impede the formation of NDMA from two DMA-containing precursors, the antibiotics tetracycline and spiramycin. The high molecular weight NOM fractions (>10KDa) were shown to be the most effective in reducing the amount of NDMA formed from the precursor chemicals. The filtrate of a C-18 non-polar cartridge was also effective at reducing NDMA formation from tetracycline (spyramycin not tested). Therefore, polar and charged NOM components may be responsible for the reduction in NDMA formation. A possible mechanism for the reduction of NDMA formation from tetracycline is complexation due to the hydrogen bonding of the DMA functional group on tetracycline to polar phenolic functional groups in the NOM.
authors: Environmental Science and Engineering Program, Institute for the Environment and Sustainability, University of California, Los Angeles, La Kretz Hall, Suite 300, Box 951496, Los Angeles, CA 90095-1496, USA; Metropolitan Water District of Southern California, 700 Moreno Avenue, La Verne, CA 91750, USA. Electronic address: shannon.roback@gmail.com.
authors: Shannon L
authors: SL
authors: Leavey-Roback
authors: Metropolitan Water District of Southern California, 700 Moreno Avenue, La Verne, CA 91750, USA.
authors: Stuart W
authors: SW
authors: Krasner
authors: Environmental Science and Engineering Program, Institute for the Environment and Sustainability, University of California, Los Angeles, La Kretz Hall, Suite 300, Box 951496, Los Angeles, CA 90095-1496, USA.
authors: Irwin H Mel
authors: IHM
authors: Suffet
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry*; D002700:Chloramines / Q000737:chemistry; D004128:Dimethylnitrosamine / Q000737:chemistry*; D004202:Disinfectants / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification
chemical_list: D000900:Anti-Bacterial Agents; D002700:Chloramines; D004202:Disinfectants; D014874:Water Pollutants, Chemical; D004128:Dimethylnitrosamine
keywords: N-nitrosodimethylamine (NDMA); Natural organic matter; Spiramycin; Tetracycline