Mass spectral characteristics of the chlorinated disinfection byproduct 2,2,4-trichloro-5-methoxy-cyclopent-4-ene-1,3-dione

The objective of this paper was to correct the mistakes of a previous interpretation of electron impact ionization (EI) mass spectrum of the chlorinated disinfection byproduct (DBP) in drinking water naming 2,2,4-trichloro-5-methoxy-cyclopent-4-ene-1,3-dione (TCMCD). Moreover the positive-ion chemical ionization (CI+) and electrospray ionization (ESI+) mass spectra were also studied. As the search of new chlorinated disinfection byproducts in drinking water is a challenge and researchers generally have to attempt to identify unknown chlorinated products generated from incompletely defined starting materials, fully understanding the mass spectra of this compound may do some help for the analysis of other unknown chlorinated disinfection byproducts.