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APPLICATION OF DNPH DERIVATIZATION WITH LC/MS TO THE IDENTIFICATION OF POLAR CARBONYL DRINKING WATER DISINFECTION BY-PRODUCTS IN DRINKING WATER
Citation:
Richardson, S D., T V. Caughran, T. Poiger, Y. Guo, AND F G. Crumley. APPLICATION OF DNPH DERIVATIZATION WITH LC/MS TO THE IDENTIFICATION OF POLAR CARBONYL DRINKING WATER DISINFECTION BY-PRODUCTS IN DRINKING WATER. OZONE: SCIENCE & ENGINEERING 22(6):653-675, (2000).
Impact/Purpose:
Determine the actual concentrations of suspected health-impacting DBPs produced using non-chlorine disinfectants, how often they occur, under what conditions they are formed, and their fate and transport in the distribution system.
Description:
A qualitative method using 2,4-dinitrophenylhydrazine (DNPH) derivatization followed by analysis with liquid chromatography (LC)/negative ion-electrospray mass spectrometry (MS) was developed for analyzing and identifying highly polar aldehydes and ketones in ozonated drinking water. Using this method, aldehydes could be easily distinguished from ketones by differences in their mass spectra and chromatographic behavior. Results for many polar-substituted aldehyde and ketone standards are presented, as well as the identification of polar disinfection by-products (DBPs) in ozonated drinking water from full-scale plants and laboratory-scale ozonation of humic acid. One polar DBP identified has not been previously
reported. This method could also potentially be used as a tool to identify carbonyl-containing DBPs from disinfectants other than ozone. However, the detection limits for the DNPH-LC/MS method are not as low as for the pentafluorobenzylhydroxylamine (PFBHA)-gas chromatography (GC)/MS method (LC/MS is typically not as sensitive as GC/MS). Therefore, it is not recommended that this method replace the PFBHA-GC/MS method, but be used as a
supplement to enable the identification of highly polar carbonyl-containing DBPs that would not be possible by GC/MS.