Chlorinated pesticides have become popular topics of research because of both their resistance to degradation and their toxicity to animals, including human beings. A Solid Phase Extraction technique was used for the extraction of the organochlorine (atraine and metolachlor) and organonitrogen (norflurazon and fluometuron) herbicides. The chlorinated herbicides was extracted from water samples using different solvents, followed by clean-up of the sample extract using C18 solid phase extraction cartridge; the analytes was eluted with 1:1 ethyl acetate:methylene chloride. The Gas Chromatographic parameters were optimized before analysis of samples. The analytes were thermally desorbed in gas chromatographic inlet and detected by gas chromatography with electron-capture detector (ECD), nitrogen phosphorus detector (NPD), and Mass Spectrometry. The instrumental detection limits were set in range of microgram per liter (µg/l). The preliminary data was statistically analyzed with ANOVA and determined to be statistically significant (P ≤ 0.05) for most of the herbicides investigated. Patterns observed were a steady increment in herbicide concentrations from north to south in both watersheds. The seasonal variation was also evident that the Rivers had higher herbicide content during spring and summer and lower content during fall and winter. Results indicated that the total concentration of carcinogenic herbicides, such as atrazine, metolachlor, norflurazon, fluometuron and other chemical pollutants were highest in Flint River. The most probable reasons for these results are accelerated rates of urban sprawl. Results also suggest that agriculture, past and present land use practices, have resulted in significant adverse impacts on the study areas.

Keywords: Gas Chromatography, ECD, NPD, Mass Spectrometry, carcinogenic herbicides, Solid Phase Extraction.