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A multiresidue analytical methodology based on a solid-phase microextraction (SPME), followed by gas chromatography-ion trap mass spectrometry (GC-IT/MS), has been developed for trace analysis of 20 known or suspected endocrine-disrupting pesticides. The SPME conditions are optimized considering several key parameters to obtain the maximum sensitivity. After the optimization, the method validation is performed, and the limits of detection (ranged from 2-150 ng/L) and the coefficient of determination (above 0.990) of studied compounds are determined for all the analytes. A robust sampling of twenty sampling points of surface water samples from the north and center of Portugal is performed, and the validated methodology is applied. In total, 20 compounds from four chemical families (13 organochlorine, 1 organophosphorus, 2 dicarboximide, and 4 pyrethroids) are studied, and the pesticides most frequently detected are eight organochlorine pesticides (α-, β-HCHs, lindane, HCB, o,p'-DDT, p,p'-DDE, p,p'-DDD, α-endosulfan), cypermethrin, and vinclozolin. [ABSTRACT FROM AUTHOR]

A SPME-GC-MS/MS method for the determination of eight organophosphorus pesticides (azinphos-methyl, chlorpyriphos, chlorpyriphos-methyl, diazinon, fenitrothion, fenthion, malathion, and methidathion) in still and fortified wine was developed. The extraction procedure is simple, solvent free, and without any sample pretreatment. Limits of detection (LOD) and quantitation (LOQ) values in the range 0.1-14.3 µg/L and 0.2-43.3 µg/L, respectively, were obtained. The LOQ values are below the maximum residue levels (MRLs) established by European Regulation for grapes, with the exception of methidathion. Coefficients of correlation (R2) higher than 0.99 were obtained for the majority of the pesticides, in all different wines analyzed. [ABSTRACT FROM AUTHOR]

Seven pyrethroids (bifenthrin, fenpropathrin, λ-cyhalothrin, permethrin, α-cypermethrin, fenvalerate, and deltamethrin) were extracted from water using C18 solid-phase extraction disks, followed by gas chromatography with an electron capture detector (GC-ECD) analysis. The limits of detection in water samples ranged from 0.5 ng L-1 (fenpropathrin) to 110 ng L-1 (permethrin), applying the calibration graph. The effects of different numbers of (re)utilizations of the same disks (up to four times with several concentrations) on the recoveries of the pyrethroids were considered. The recoveries were all between 70 and 120% after four utilizations of the same disk. There was no difference between these recoveries at a confidence level of 95%. [ABSTRACT FROM AUTHOR]