Clofibric acid (CA) and the herbicide mecoprop (MCPP) were detected in Swiss lakes from populated areas and in the North Sea in the low nanograms per liter range. Gas chromatography/mass spectrometry (GC/MS) and MS/MS were used to distinguish the two isomeric compounds (analyzed as the methyl esters). The concentrations of CA in the North Sea (1-2 ng/L) reach levels of those of "classical" environmental pollutants such as R-and γ-hexachlorocyclohexane. The data suggest a high mobility of CA in the aquatic environment. The changed relative concentrations of CA and MCPP in the North Sea as compared to those in the lakes and in comparison to production figures indicate a much more persistent behavior for CA than for MCPP. The data also indicate that some pharmaceutical compounds need evaluation on ecotoxicological grounds in very much the same way as do agricultural chemicals.

No abstract

No abstract

The methods of accelerated solvent extraction (ASE) and supercritical fluid extraction (SFE) of polycyclic aromatic hydrocarbons (PAHs), aliphatic hydrocarbons, and chlorinated hydrocarbons from marine samples were investigated. The results of extractions of a certified sediment and four samples of suspended particulate matter (SPM) were compared to classical Soxhlet (SOX), ultrasonication (USE), and methanolic saponification extraction (MSE) methods. The recovery data, including precision and systematic deviations of each method, were evaluated statistically. It was found that recoveries and precision of ASE and SFE compared well with the other methods investigated. Using SFE, the average recoveries of PAHs in three different samples ranged from 96 to 105%, for ASE the recoveries were in the range of 97-108% compared to the reference methods. Compared to the certified values of sediment HS-6, the average recoveries of SFE and ASE were 87 and 88%, most compounds being within the limits of confidence. Also, for alkanes the average recoveries by SFE and ASE were equal to the results obtained by SOX, USE, and MSE. In the case of SFE, the recoveries were in the range 93-115%, and ASE achieved recoveries of 94-107% as compared to the other methods. For ASE and SFE, the influence of water on the extraction efficiency was examined. While the natural water content of the SPM sample (56 wt %) led to insufficient recoveries in ASE and SFE, quantitative extractions were achieved in SFE after addition of anhydrous sodium sulfate to the sample. Finally, ASE was applied to SPM-loaded filter candles whereby a mixture of n-hexane/acetone as extraction solvent allowed the simultaneous determination of PAHs, alkanes, and chlorinated hydrocarbons.

No abstract