Simulation of biological degradation of aromatic amines in river bed sediments.

Testfilter experiments are reported for river Elbe water spiked with aromatic amines in order to determine biodegradation rates. For river Elbe water the mean degradation rate of DOC (C0 = 6.64 mg l-1) was 26.7 +/- 8.8% after 6.8 days. No significant effect on the DOC degradation rate was observed with the addition of aromatic amines. Large differences in the biodegradation behaviour of the aromatic amines were observed: aniline was eliminated within 3 h, whereas the degradation of 2-nitroaniline was only 40% after 14 h effective contact time. Degradation curves were mostly of a simple logarithmic type, demonstrating first-order kinetics. The degradation rate of 2,4,6-trichloraniline increased by a factor of 20 within 6 weeks due to the adaptation of the testfilter biofilm. A linear relationship between available pKa-values and the logarithm of the experimental degradation rates was found. Thus, the results of the testfilter experiments may be extended to the estimation of the biodegradability of non-tested aromatic amines.

Determination of aromatic amines in surface waters and comparison of their behavior in HPLC and on sediment columns.

An analytical method based on solid-phase extraction (SPE) with a polymeric material, HPLC separation on a modified C18 material, and diode-array detection is presented for the determination of aromatic amines in the ng L(-1)-concentration range. These potentially toxic compounds in polluted water samples can be sampled by using SPE with an amino phase to clean the eluate. Column experiments were performed to characterize the transport behavior of aromatic amines in an aquifer sediment. For nineteen aromatic amines, linear correlations were found between the adsorption coefficient, Kd, estimated from column experiments, and capacity factors, k', measured by isocratic reversed-phase HPLC (RPHPLC).

Determination of aliphatic and alicyclic amines in water by gas and liquid chromatography after derivatization by chloroformates.

Two new methods were developed for the analysis of aliphatic (n-propylamine, pentylamine, hexylamine, heptylamine, octylamine) and alicyclic (pyrrolidine, morpholine, piperidine, piperazine) amines in water samples after derivatization and liquid-liquid-extraction. The carbamate-derivatives formed were determined by GC/MS (trichloroethyl carbamates) as well as by HPLC/fluorescence detection (9-fluorenylmethyl carbamates) in a concentration range between 0.05 and 1.0 microg/l suitable for drinking water analysis. Applications to German rivers and sewage plants show that both new methods produce corresponding results in analysing aliphatic and alicyclic amines in surface waters as well as in waste water samples.