The structure of a new chlorinated disinfection byproduct
(DBP) in drinking water is studied. The new DBP was
prepared through chlorinating itsbest precursor, and it was
extracted and isolated from the chlorination products. Its
structure is identified as 2,2,4-trichloro-5-methoxycyclopent-4-ene-1,3-dione (TCMCD) through FTIR, MS, 1H NMR,
and 13C NMR spectroscopic analysis and single-crystal
X-ray diffraction method. Results of the Ames test with tester
strain TA100 indicated that the newly identified DBP
TCMCD is a mutagen.