Main findings and conclusions of the implementation of Directive 76/464/CEE concerning the monitoring of organic pollutants in surface waters (Portugal, April 1999-May 2000)

The purpose of this paper is it) relate the implementation of Directive 76/ 464/CEE concerning the survey of priority dangerous substances and indicate the main priority pollutants encountered throughout a systematic monitorin g program carried out in Portugal during a period of 14 months (April 1999- May 2000). Contrary to what it seems, the implementation of such a Directiv e is not straightforward owing to the large number of compounds and samples to be analyzed at trace levels. During this period of time, 115 priority s emivolatile organic compounds (SVOCs), 41 volatile organic compounds (VOCs) , six organotin compounds, 14 heavy metals. phosphate, nitrates, nitrites a nd ammonia were determined in 644 surface water samples (corresponding to 1 4 months and 46 sites). In addition, priority SVOCs were also determined in sediment, mussels and fish (muscle and liver). This paper reports the proc edure and analytical tools used and necessary to determine the levels of 11 5 priority toxic and persistent semivolatile organic compounds selected fro m the EC Council Directive list (76/464/EEC). An advanced analytical protoc ol was developed involving enrichment of water samples in Oasis solid-phase extraction cartridges (SPE) in the Lisbon laboratory with a Gilson ASPEC X L automated extraction system and by sending the enriched cartridges to Bar celona by aeroplane at 4 C, where elution and analysis were performed. Fina l determination was performed with gas chromatography-electron ionization m ass spectrometry (GC-EI-MS). Acidic herbicides were determined by liquid ch romatography with diode array detection. Owing to the great amount of data generated throughout the monitoring study, statistical analysis of the more representative contaminants was performed, allowing the identification of the more relevant contamination sources, percentages of findings and the de scription of their temporal and spatial (geographical) distributions. Recom mendations and compounds that should be included in future monitoring progr ams are given.