title: Evaluation on the generative mechanism and biological toxicity of microcystin-LR disinfection by-products formed by chlorination.
abstract: To control the environmental risk of microcystin-LR disinfection by-products (MCLR-DBPs), we evaluated their generative mechanisms and biological toxicity by mass spectrometry technology and protein phosphatase inhibition assay. Subject to chlorination, MCLR was totally transformed within 45 min and generated 5 types of MCLR-DBPs with the chemical formulas of C34H54N10O12, C49H76N10O14Cl2, C49H77N10O15Cl, C49H75N10O13Cl, and C49H76N10O14. Isomers for each MCLR-DBP type were identified and separated (products 1-9), indicating that the conjugated diene in Adda residue was a major target site of disinfection. Though, subsequent toxicity test showed the toxicity of MCLR-DBPs on protein phosphatase 1 decreased with the extending of disinfection by and large, these DBPs still possessed certain biological toxicity (especially for product 5). Combined with quantitative analysis, we thought the secondary pollution of MCLR-DBPs in drinking water also deserved further attention. This study offers valid technique support for MCLR-DBPs identification, contributes to a comprehensive cognition on their hazard, and thus has great significance to prevent and control the environmental risk induced by microcystins and their DBPs.
authors.affiliation: College of Population, Resources and Environment, Shandong Normal University, 88# East Wenhua Road, Jinan 250014, PR China. wansongzong@gmail.com
authors.forename: Wansong
authors.initials: W
authors.lastname: Zong
authors.forename: Feng
authors.initials: F
authors.lastname: Sun
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Sun
mesh_terms: D004203:Disinfection; D054879:Halogenation; D008387:Marine Toxins; D052998:Microcystins / Q000737:chemistry* / Q000633:toxicity*; D054645:Protein Phosphatase 1 / Q000037:antagonists & inhibitors; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000633:toxicity*; D018508:Water Purification
chemical_list: D008387:Marine Toxins; D052998:Microcystins; D014874:Water Pollutants, Chemical; D054645:Protein Phosphatase 1; C057862:cyanoginosin LR