Determination of highly polar compounds in water samples around former ammunition plants

A 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.