Disinfection is an important step in drinking water treatment process.However,disinfectants such as chlorine or chloramine can generate numerous halogenated disinfection byproducts(DBPs)with carcinogenicity,teratogenicity,and mutagenicity,which pose great threat to drinking water safety.More than 700 DBPs have been detected and identified in drinking water by researchers.The molecular weights of these known DBPs are all below 800 Da,and the understanding of high-molecular-weight DBPs is very limited.In this study,a detection method for high-molecular-weight DBPs was established based on matrix-assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF MS).It was found that when the matrix was 2,5-dihydroxybenzoic acid,the cationization agent was sodium trifluoroacetate,the sandwich deposition method was used,the reflection-positive ion mode was applied,and the laser intensity was 90％,the highest signal intensity of high-molecular-weight DBPs could be obtained.At such condition,the signal reproducibility was maximized,the sum of the signal-to-noise ratio of new high-molecular-weight DBPs reached 136.2,and the coefficient of variation(CV)was 4.77％.Five new high-molecular-weight DBPs were detected in simulated drinking water using the above method.On such basis,a formula/structure identification method for unknown high-molecular-weight DBPs was established by isotopic pattern analysis,TOF/TOF tandem mass spectrometry,and database verification.With this method,the five new high-molecular-weight DBPs were determined to be oligosaccharide carboxylic acids.
关键词
高分子量消毒副产物/基质辅助激光解吸电离飞行时间质谱/阳离子化试剂/检测/识别
Key words
high-molecular-weight disinfection byproducts/matrix-assisted laser desorption ionization time-of-flight mass spectrometry/cationization agent/detection/identification
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