CLEANUP AND CONFIRMATION PROCEDURES FOR GAS-CHROMATOGRAPHIC DETERMINATION OF PESTICIDE-RESIDUES IN CONTAMINATED WATERS .1.

The effects of sulphuric acid, potassium hydroxide and chromic acid on eleven organochlorine and ten organophosphorus pesticides were investigated. The treatments destroy some pesticides totally or partially, leave others unaltered and have a clean-up effect. These reactions can be used to confirm the presence of an identified pesticide. The clean-up extracts in the environmental samples facilitate the identification of the organochlorine and organophosphorus pesticides and their quantitative analysis. The results obtained for contaminated surface waters show the usefulness of these methods for multi-residue capillary gas chromatography without the need for other additional separative chromatographic steps to avoid interferences or the use of a highly sensitive mass spectrometer for confirmation.