. . . . "Evaluation of Functional Groups Responsible for ChloroformFormation during Water Chlorination Using Compound Specific IsotopeAnalysis" . . . "The apparent kinetic isotope effect and \u03B413C signature of chloroform, produced upon chlorination of NOM modelcompounds, are used to gain insight into chloroform formation." . . . . . . . . . . "Compound-specific isotope analysis was used to monitor the \u03B413C signature of chloroform produced upon the chlorinationof model compounds representing natural organic matter functionalgroups (resorcinol, acetylacetone, acetophenone, phenol, and 2,4,6-trichlorophenol)and a natural water sample. For each model compound, a different apparentkinetic isotope effect was found for chloroform formation. Normalisotope effects were found for resorcinol, acetylacetone, and acetophenone,and ranged from 1.009 \u00B1 0.002 to 1.024 \u00B1 0.004. For thetwo phenols, an inverse effect was found (0.980 \u00B1 0.004). LakeZu\u0308rich water also had a inverse effect (0.997 \u00B1 <0.001)indicating that phenols are likely chloroform precursors in NOM, butthat other functional groups may also participate. The apparent 13C kinetic isotope effect for the addition/elimination reactionof 1,1,1-trichloropropanone mediated by OH\u2212 to yieldchloroform is 1.014 \u00B1 0.002. A comparison of this value to thosefound for the chlorination of the model precursors and an evaluationof the differences in chloroform production kinetics for the differentmodel precursors argue against a mechanism in which all NOM precursorsreact via a common intermediate. Compound specific isotope analysismay give additional insights into chloroform formation mechanismsbeyond those allowed by current techniques." . .