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A multiresidue method based on extraction with ethyl acetate has been used at the Swedish National Food Administration since 1989 to monitor pesticide residues in fruit and vegetables. The method has been continuously adjusted, resulting in simple and quick analyses of pesticide residues. To recover basic pesticides, the addition of an alkali is necessary. The addition of sodium hydrogen carbonate has been shown to recover all pesticides effectively without any degradation. The liquid chromatography (LC) with tandem mass spectrometry (MS/MS) technique has made it possible to analyse more polar pesticides and to replace many single methods. The latest development in the multiresidue method, comprising the use of gas chromatography (GC) with MS/MS, has further improved the analysis by replacing the conventional GC detectors. The need for cleanup has been reduced or eliminated entirely. Consequently, the method has been simplified in a way that makes it possible to recover all included analytes in many different matrices in one single extraction and to detect them either with GC-MS/MS or with LC-MS/MS.

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Concentrations and enantiomer fractions (EFs) of organochlorine compounds (OCs) were determined in tissues of gray seal (Halichoerus grypus) and salmon (Salmo salar) originating from the Baltic Sea. The selected seal specimens ranged from starved to unstarved animals, and some of them suffered from a disease complex, while the salmon samples originated from individuals, which were known to produce offspring with and without the M74 syndrome. Significant differences in residue levels and EFs were found between seal groups but not between M74 salmon and non-M74 salmon. The relations between chemical and biological variables of seal samples were investigated with multivariate statistics. Poor health status correlated strongly with age, while bad nutrition condition was associated mainly with high pollution loads and distinctively nonracemic chiral OC compositions. High biotransformation rate (as indicated by fraction of chlordane metabolites in relation to total level of chlordanes) was also associated with large deviations from racemic values and high contaminant levels.

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