DETERMINATION OF CHLOROANILINE TRACES IN ENVIRONMENTAL WATERS BY SELECTIVE EXTRACTION WITH 2 TRAPS IN TANDEM AND LIQUID-CHROMATOGRAPHY

Selective liquid-solid extraction from environmental waters of 14 chioroanilines was achieved by using a two-trap tandem system, one containing a nonspecific adsorbing material, such as graphitized carbon black (Carbopack B), and the other one filled with a resin-based strong cation exchanger. After percolation through the Carbopack column (extraction cartridge) of water samples, the two traps were connected in series, acetonitrile acidified with HCI, 10 mmol/L, was allowed to flow along them, and chioroanilines displaced from the extraction cartridge were selectively readsorbed via hydrogen bonding on the strong acid exchanger column (Isolation cartridge). After this column was washed, the analytes were eluted from the isolation cartridge with 1 mL of aqueous acetonitrile basified with KOH, 0.1 mol/L. After suitable neutralization, 0.2 mL of this solution was directly injected Into the liquid chromatographic apparatus, which was operated isocratically In the reverse-phase mode with UV detection at 240 nm. The analytical recoveries of the 14 chloroanilines were higher than 88%. The limits of detectability of the analytes considered were well below 0.1 μg/L. The effectiveness in terms of recovery and selectivity of the two traps in series was compared with three other cartridges, which contained a chemically bonded siliceous material (C18), Carbopack, and a cation exchanger. These latter two cartridges were the very same we used In tandem, but in this case they were operated individually. © 1990, American Chemical Society. All rights reserved.