DS EN 12918:2000 Water Quality - Determination Of Parathion, Parathion-Methyl And Some Other Organophosphorus Compounds In Water By Dichloromethane Extraction And Gas Chromatographic Analysis Describes the extraction processes and gas chromatographic (GC) methods for determining parathion, parathion-methyl and some other organophosphorus compounds in drinking waters, surface waters and was