SURFACE-WATER ANALYSIS (TRACE-ORGANIC CONTAMINANTS) AND EC REGULATIONS

A short description of the EC directives and recommended methods shows that few organics have to be controlled in surface waters for drinking-water purposes (a total of six PAHs, phenolics, surfactants reacting with methylene blue, dissolved hydrocarbons and a total of three pesticides). The specific analytical parameters for the given group are obviously inadequate. New analytical methods have been developed during recent years and are discussed. The list of organic compounds to be eliminated from discharges (Directive EC 76/464) was taken as an indication of compounds to be monitored and this, too, is discussed. Most of the methods involve a preconcentration step, a clean-up of the extracts and a chromatographic separation by gas or liquid chromatography. Because many methods have been derived from those used for drinking water, special attention is given to the sources of errors which are likely to occur when they are applied to surface waters and to new methods which reflect current analytical trends (reduction of organic solvents, solid-phase extraction, automation of the sample preparation step, and multiresidue analyses). Examples are given for the trace-determination of compounds such as PAHs, phenolics, aniline derivatives, linear alkylbenzene-sulfate and sulfonates, and pesticides. Special attention is also given to on-line multiresidue methods.