Determination of chlorinated pesticides in potable water

A procedure is described for monitoring organochlorine pesticides in potable water. Material adsorbed from water on to Amberlite XAD-2 macroreticular resin was eluted with n-hexane and the concentrated eluate was analyzed without further treatment. Electron capture (63Ni) gas chromatography utilizing a column of 4% QF-1 and 2% SE-30 on 80-100 mesh HP Chromosorb W at 180 degrees permitted identification of organochlorine pesticides and indicated the presence of phthalates. Confirmatory qualitative and quantitative analyses were done by specific ion-monitoring mass spectrometry. Levels determined in Ottawa drinking water were 17 ppt alpha-BHC, 1.3 ppt lindane, 0.7 ppt aldrin, and less than 0.05 ppt for each of heptachlor, heptachlor epoxide, dieldrin, endrin, chlordane, o,p'-DDT, p,p'-DDD, p,p'-DDT, and p,p'-DDE.