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A new system has been developed for rapid on-line SPE-LC-MS-MS analysis of a wide spectrum of trace level pesticides in drinking and surface water. The system employs a serial arrangement of I',,vo different turbulent flow columns (TFC; polymer based column in front, carbon based column back) for rapid extraction (Turbulent flow solid phase extraction; TFSPE) from small sample volumes (10 mL) at high flow rates (5 mL min 1). Purely organic eluent is used for TFC elution, and the effluent is re-mixed with water in a mixing chamber in front of the HPLC column to provide efficient analyte focusing. This methodology allows to use a short monolithic LC column for the following fast on-line LC-APCI-MS-MS analysis.This approach gives quantitative results for nearly 30 pesticide species (triazines, phenyl ureas, organophosphorous pesticides and others) in less than 14 min and, thus, allows considerably increased sample throughput. The method is well reproducible, robust and extremely sensitive achieving detection limits bef,,veen 0.1 and 1 ng L 1.As the comparison of internal and external calibration methods showed, potential matrix effects on the qualily of the results are managed by the method in a very effective manner.Real pesticide concentrations determined in drinking water and surface water samples showed significant temporal variations but were constantly below the concentration limit for individual pollutants of 100 ng L 1.

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SummaryA method was developed for the determination of nitrobenzoic acids and nitrophenols as well as of diaminoaromatics and was applied to the analysis of water samples from the former ammunition plant at Elsnig (Saxony, Germany).The procedure is based on a preseparation into a neutral, an acidic and a basic fraction by multi-step extraction at different pH values followed by HPLC analysis with UV and electrochemical detectors, coupled in series.Applying optimized enrichment conditions, all investigated compounds were extracted from spiked distilled water with recoveries > 80 % and variation coefficients < 7 %. Similar results were obtained with spiked ground water samples. After enrichment, all compounds can be analysed by HPLC with UV detection at concentrations below 100 ng L -1. The electrochemical detector (ELCD) allowed a selective and sensitive detection of the nitrophenols and especially of the diaminoaromatics and, therefore, provides some advantages in the analysis of real samples.