Presence Of Organic Micropollutants Research Articles

On the presence of PCDD/Fs and other chlorinated hydrocarbons in the second generation of the European Reference Soil Set--the EUROSOILS.

The second generation of the European Reference Soil-Set, the so-called EUROSOILS, has been introduced recently. The presence of organic micro-pollutants in this new type of reference materials has already been studied for polycyclic aromatic hydrocarbons, triazines, phenylureas and other pesticides. The already large amount of data concerning the level of different contaminants, the elemental composition and matrix properties is completed by a survey by means of GC/MS on the polychlorinated dibenzodioxins/furans (PCDD/Fs) and other chlorinated hydrocarbons. Higher concentrations for 4,4'-DDT in EUROSOIL 2 (10.57 +/- 0.02 ng/g), for dieldrin in EUROSOIL 3 (8.85 +/- 0.87 ng/g) and for heptachlor-epoxide in EUROSOIL 4 (5.86 +/- 0.16 ng/g) could be detected. Sum concentrations for PCDD/Fs were 15.02 ng/kg (EUROSOIL 1), 214.29 ng/kg (EUROSOIL 2), 873.32 ng/kg (EUROSOIL 3), 54.47 ng/kg (EUROSOIL 4) and 119.61 ng/kg (EUROSOIL 5).

The determination of polychlorinated biphenyls in municipal sewage sludges using microwave-assisted extraction and gas chromatography-mass spectrometry

The presence of organic micropollutants [such as poly(chlorobiphenyls)] in municipal sewage sludges is a major problem on account of risks associated with the agricultural valorisation of the sludges. In France, since January 1998, maximum values for trace organic pollutants are imposed [0.8 mg kg–1 dry matter for the sum of seven poly(chlorobiphenyls)]. The aim of this study was to develop a reliable, accurate and fast analytical procedure (extraction, clean-up, quantification) in order to determine polychlorinated biphenyls in municipal sewage sludges. Such pollutants could be efficiently extracted from dried sewage sludge samples using microwave-assisted extraction. This technique affords several advantages as compared to the classical Soxhlet extraction, mainly rapidity and reduction in solvent consumption. Extractions (10 min under 30 W with 30 ml hexane–acetone 1:1) were conducted in the presence of copper to avoid sulfur interferences in the extracts. The latter were further concentrated and purified onto disposable silica cartridges. After final concentration and addition of the internal standard, they were analysed by gas chromatography coupled to mass spectrometry (in the selected ion monitoring mode). Two types of sludges (from Acheres and Valenton sewage treatment plants near Paris, France) were analysed, whose polychlorobiphenyl concentrations differed largely (Acheres sludge being the most contaminated). The microwave extraction compared favourably with the classical Soxhlet extraction. In addition, the sludge concentrations found with our experimental procedure were close to the analyses made by another laboratory, even though some discrepancy was noted.

Multivariate micropollutants analysis in marine waters

The monitoring of water quality today provides a great quantity of data consisting of the values of the parameters measured as a function of time. In the marine environment, and especially in the suspended material, increasing importance is being given to the presence of organic micropollutants, particularly since some are known to be carcinogenic. As the number of measured parameters increases examining the data and their consequent interpretation becomes more difficult. To overcome such difficulties, numerous chemometric techniques have been introduced in environmental chemistry, such as Multivariate Data Analysis (MVDA), Principal Component Analysis (PCA) and Partial Least Squares Regression (PLSR). The use of the first technique in this work has been applied to the interpretation of the quality of Augusta bay, by measuring the concentration of numerous organic micropollutants, together with the classical water pollution parameters, in different sites and at different times. The MVDA has highlighted the difference between various sampling sites whose data were initially thought to be similar. Furthermore, it has allowed a choice of more significant parameters for future monitoring and more suitable sampling site locations.