Formation of trihalomethanes by chlorination of surface water

Chloroform, bromodichloromethane, dibromochloromethane, bromoform, and dichloroiodomethane have been found in chlorinated drinking water. In addition to these five compounds, the other possible trihalomethanes (chlorodiiodomethane, bromochloroiodomethane, dibromoiodomethane, bromodiiodomethane, and iodoform) can also be formed by chlorination of surface water containing bromides and iodides. Mass spectra for each of these ten compounds were obtained.