The detection of pesticide residues in water supplies
David Lee Barry, Union College - Schenectady, NY
Union College Only
The use of organic chemicals as pesticides has increased greatly in recent years and continues to do so, since these pesticides offer advantages of greater effectiveness, more selectivity, and lower toxicity to mammals, than the previously used inorganic pesticides, such as arsenic compounds. The problem of pollution of water supplies by these pesticides becomes more important with this increasing usage, and with the increasing pressures on our water resources. Pesticides may find their way into water supplies by various means, such as runoff of rain water from crop land or other pesticide-treated land, direct application to bodies of water, for aquatic weed or algae control, and by accidents in the application of pesticides to adjacent land areas, as in aerial spraying. The steps of the proposed method are, extraction of the pesticide from a water sample with an organic solvent, isolation of the pesticide from other extraction compounds by a vapor phase chromatograph and fraction collector, identification of the pesticide by infra-red analysis, and quantitative measurement using either the response of the chromatograph detector or the infra-red spectrophotometer.