Removal of organic pollutants from aqueous solution. V. Comparative study of the extraction, recovery and chromatographic separation of some organic insecticides using unloaded polyurethane foam columns

The concentration of dissolved insecticides in aqueous media was determined by chromatographic separation on polyurethane foam columns. The results of preliminary screening tests on the removal of insecticides by the unloaded polyurethane foam indicated that a reasonable percentage of the insecticides was retained on the foam. Therefore attempts were made to extract these compounds from aqueous media using foam columns. Various parameters affecting the retention and separation of these compounds were studied, including temperature, flow-rate, pH, insecticide concentration, shaking time, sample volume and eluting solvent. The complete separation and quantitative recovery of these compounds from the foam with acetone in a Soxhlet extractor were achieved. The method can be used to preconcentrate insecticides in tap water and modified to determine dissolved insecticides in industrial and natural waters. Polyurethane foam has a good capacity for use when large volume samples need to be handled and is an inexpensive sorbent compared to other known solid sorbents.