Identification, toxicity and control of iodinated disinfection byproducts in cooking with simulated chlor(am)inated tap water and iodized table salt

Yang Pan; Xiangru Zhang; Yu Li

doi:10.1016/j.watres.2015.10.002

Identification, toxicity and control of iodinated disinfection byproducts in cooking with simulated chlor(am)inated tap water and iodized table salt

Water Res. 2016 Jan 1:88:60-68. doi: 10.1016/j.watres.2015.10.002. Epub 2015 Oct 8.

Authors

Yang Pan¹, Xiangru Zhang², Yu Li³

Affiliations

¹ Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
² Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China. Electronic address: xiangru@ust.hk.
³ Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China.

PMID: 26474150
DOI: 10.1016/j.watres.2015.10.002

Abstract

Chlorine/chloramine residuals are maintained in drinking water distribution systems to prevent microbial contamination and microorganism regrowth. During household cooking processes (e.g., soup making), the residual chlorine/chloramines in tap water may react with the iodide in iodized table salt to form hypoiodous acid, which could react with remaining natural organic matter in tap water and organic matter in food to generate iodinated disinfection byproducts (I-DBPs). However, I-DBPs formed during cooking with chloraminated/chlorinated tap water are almost completely new to researchers. In this work, by adopting precursor ion scan of m/z 127 using ultra performance liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry, many new polar I-DBPs formed during cooking with chloraminated/chlorinated tap water were detected and proposed with structures, of which 3-iodo-4-hydroxybenzaldehyde, 3-iodo-4-hydroxybenzoic acid, 3-iodo-4-hydroxy-5-methylbenzoic acid, diiodoacetic acid, 3,5-diiodo-4-hydroxybenzaldehyde, 3,5-diiodo-4-hydroxybenzoic acid, 2,6-diiodo-4-nitrophenol, 2,4-diiodo-6-nitrophenol, and 2,4,6-triiodophenol were confirmed with standard compounds. With the aid of ultra fast liquid chromatography/ion trap-time of flight-mass spectrometry, molecular formula identification of five new I-DBPs (C8H5O4I, C7H4NO4I, C8H5O5I, C7H4NO5I, and C8H6O3I2) was achieved. A developmental toxicity with a recently developed sensitive bioassay was conducted for the newly identified I-DBPs, suggesting that phenolic I-DBPs (except for iodinated carboxyphenols) were about 50-200 times more developmentally toxic than aliphatic I-DBPs. The major I-DBPs in a baseline simulated cooking water sample were determined to be from 0.72 to 7.63 μg/L. Polar I-DBPs formed under various disinfection and cooking conditions were compared, and suggestions for controlling their formation were provided.

Keywords: Chloramination; Chlorination; Cooking; DBPs; Disinfection byproducts; Tap water.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Chloramines / chemistry*
Cooking*
Disinfection / methods
Drinking Water / chemistry*
Embryo, Nonmammalian
Flour
Halogenation
Hydrocarbons, Iodinated / analysis*
Hydrocarbons, Iodinated / chemistry
Iodine / chemistry*
Iodine Compounds / analysis*
Iodine Compounds / toxicity
Polychaeta / drug effects*
Polychaeta / embryology
Sodium Chloride, Dietary
Water Pollutants, Chemical / analysis

Substances

Chloramines
Drinking Water
Hydrocarbons, Iodinated
Iodine Compounds
Sodium Chloride, Dietary
Water Pollutants, Chemical
iodized salt
Iodine
chloramine