Büro für Altlastenerkundung und Umweltforschung
Dr. Rainer Haas
Stadtwaldstr. 45a, D-35037 Marburg, Tel.: 06421/93084, Fax: 06421/93073
Ground Water Pollution with Aromatic Amines
Emissions from a former Waste Disposal Site
1,6Rainer Haas, 2Andreas Steih-Winkler, 3Torsten C. Schmidt, 3Klaus Steinbach, 4Eberhard v. Löw, 5,6Alfred Krippendorf
1 Büro für Altlastenerkundung und Umweltforschung, Stadtwaldstr. 45a, D-35037 Marburg
2 Magistrat der Stadt Marburg, Umweltamt, D-35035 Marburg
3 Philipps-Universität Marburg, FB Chemie, Hans-Meerwein-Str., D-35032 Marburg
4 Institut für Immunologie, Bereich Umwelthygiene, Pilgrimstein 2, D-35037 Marburg
5 Hazard Control GmbH, Trauen test centre, D-29328 Faßberg
6 Biolabor Trauen, Eugen-Sänger-Str., D-29328 Faßberg
Corresponding author: Dr. Rainer Haas
Abstract
In the 1980ies aromatic amines were detected in the ground water near a waste disposal site in Marburg/Hesse with a photometrical sum parameter. With two new derivatization methods, bromination at the aromatic ring and substitution by iodine after diazotization, some of the aromatic amines could be identified and quantified in this ground water. The identification was done with gas chromatography/mass spectrometry (GC/MS), the quantification with gas chromatography/electron capture detector (GC/ECD). Aniline, aminotoluenes, chloroanilines and chloromethylanilines were identified as the main aromatic amines present in the ground water.
Keywords: Aromatic amines, analysis; aromatic amines, derivatization, analysis; aromatic amines, ground water; derivatization, bromination; derivatization, iodination; gas chromatography; waste disposal, emission; waste disposal, investigation
1 Introduction
Many aromatic amines are used in the industrial production of pesticides, dyestuffs, pharmaceuticals and plastics. Most of them are polar, have a high solubility in water and are therefore rather mobile in aquifers. Some of them have a high acute and chronic toxicity [1-4].
In the 1980ies aromatic amines were detected in the ground water near a waste disposal site in Marburg/Hesse with a photometrical method [5,6], but at that time it was not possible to identify single compounds. Recently two new analytical methods for the gas chromatographic detection of aromatic amines after derivatization were developed in our group. With these methods we were able to investigate degradation products of nitroaromatic explosives more closely [7-12]. In this communication we describe the application of both methods to ground water from the waste disposal site.
2 Experimental
2.1 Enrichment procedure
1 l water sample was basified (pH 9) with a 10 M NaOH solution. If necessary, the samples were filtered. The water sample was extracted with 200 mg styrene-diviylbenzene-copolymer (HR-P, Macherey-Nagel) and the aromatic amines were eluated from the cartrige with 2 ml methanol/acetonitrile 1/1.
2.2 Derivatization by bromination of the aromatic ring
1 ml of the SPE eluate was mixed with 3 ml glacial acetic acid and 0.25 ml bromination solution (containing 25 % (v/v) bromine in glacial acetic acid) and shaked. After a reaction time of 15 min at room temperature the surplus of bromine was destroyed with 0.5 ml saturated sodium sulfite solution. 5 ml water were added, the solution was basified with 7 ml 10 M NaOH solution. The solution was cooled to room temperature in a water bath and extracted with 2 ml cyclohexane for 15 min. The cyclohexane extract was filled in autosampler vials for the gas chromatographic analysis [7-10]. The reaction scheme is shown in Figure 1.
2.3 Derivatization by iodination with a sandmeyer-like reaktion
To 1 ml of the SPE eluate 5 ml water, 0.2 ml hydriodic acid (55%), containing iodine, and 0.5 ml 1% sodium nitrite solution were added for diazotization. After a reaction time of 20 min at room temperature the surplus of nitrite was destroyed by addition of 1 ml 5% amidosulfonic acid. The solution was shaken for 45 min and then heated in a water bath at a temperature of 100°C for 5 min. Thus the diazo group is substituted by iodine. The surplus of iodine was destroyed with 0.5 ml saturated sodium sulfite solution. The solution was basified with 0.5 ml 10 M NaOH solution, cooled to room temperature in a water bath and then extracted with 2 ml cyclohexane for 15 min. The cyclohexane extract was filled in autosampler vials for the gas chromatographic analysis [7,8,11,12]. The reaction scheme is shown in Figure 1.
Figure 1: Reaction scemes of the derivatizations
2.4 Reference compounds
51 aromatic amines were used as reference compounds for the investigation of the water samples, compriszing aniline, methylanilines, nitroanilines, aminotoluenes, chloroanilines, chloromethylanilines, naphthylamines, benzidine and aminobiphenyls. The recovery rates of these compounds after derivatization and extraction with cyclohexane were always > 90%. The detection limits are between 0.01 and 0.8 µg/l. 8 compounds could not be detected with the iodination and 10 compounds could not be detected with the bromination method (table 1).
2.5 Gas chromatographic conditions
GC/ECD analysis was done with a gas chromatograph HP 5890 II+ with autosampler and data acquisition with Gynkosoft V 5.32. The carrier gas was nitrogen (head pressure 100 kPa). The temperature of the injector block was 250°C, of the detector 300°C. The injection volume was 1 or 5 µl. For the separation a DB 5 capillary column, 30 m * 0.25 mm I.D., 0.25 µm df was used. The detection was done with an electron capture detector (ECD).
For the separation of the brominated aromatic amines the oven temperature was held at 170°C for 18 min, then it was raised at 10°C min-1 to 230°C and held for another 20 min.
For the separation of the iodo derivatives the temperature programme was started at 150°C, after 11 min the temperature was raised at 10°C min-1 to 230°C, then held for another 11 min.
GC/MS analysis were done with a gas chromatograph HP 6890 with autosampler. The carrier gas was helium (head pressure 100 kPa). The temperature of the injector block was 230°C, the injection volume 1 µl. For the separation a HP 5 MS capillary column, 30 m * 0.25 mm I.D., 0.25 µm df was used. The detection was done with a mass selective detector (MSD). For GC/MS investigations the following temperature program was used: starting temperature: 50°C (2 min), 10°C min-1 to 120°C, 20°C min-1 to 280°C, 280°C (8 min).
3 Results and discussion
15 ground water samples from the area of the waste disposal site (group a) and 12 ground water samples near the site (group b) were investigated with both derivatization methods. Quantitative determination with GC/ECD was done for 51 aromatic amines, most of them with both derivatization methods. The identification of the brominated and iodinated derivatives was done with GC/MS.
In the group a samples very high concentrations of aromatic amines were found (up to 550 µg/l). Aniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, 4-nitroaniline, 2-chloroaniline, 3-chloroaniline, 3,4-dichloroaniline, 4-chloro-2-methylaniline and two other chloromethylaniline isomers were identified. The main pollutants were aniline and chloromethylanilines, in one sample 3-chloroaniline. The investigated polynuclear aromatic amines 1-naphthylamine, 2-naphthylamine, benzidine and 2-aminobiphenyl were either all present (four samples) or not all. This shows, that these polynuclear aromatic amines are not mobile in the aquifer.
In group b samples aniline, 3-methylaniline, 4-methylaniline, 2-chloroaniline, 3-chloroaniline, 2,6-dimethylaniline and the two unknown chloromethylanilines were identified. The concentrations of the aromatic amines are lower than in the samples from the waste disposal, max. 12,4 µg/l, because of dilution with other ground water. Polynuclear aromatic amines were not detected.
In all samples some peaks were detected with GC/ECD (both after bromination and iodination), that could not be identified. The gas chromatographic fingerprints of most samples are similar.
In Figure 2 the GC/ECD chromatograms of a water sample from (A) and near (B) the waste disposal site after bromination are shown.
Figure 2: GC/ECD chromatograms of bromated water samples from (A) and near (B) the waste disposal; derivatives of identified aromatic amines: 1: 4-methylaniline; 2: 2-chloroaniline; 3: aniline; 4,5: chloromethylanilines; 6: 3-methylaniline and 7: 3-chloroaniline.
The results show, that derivatization of aromatic amines by bromination and iodination can be used for identification and determination of aromatic amines in ground water samples. The methods are highly selective and sensitive and most of the matrix interferences are eliminated by the extraction and derivatization procedure.
4 References
[1] Domsch, K.H. (1992): Pestizide im Boden. VCH-Cerlag, Weinheim
[2] de Kok, A.; Vos, Y.J.; van Garderen, C.; de Jong, T.; van Opstal, M.; Frei, R.W.; Geerdink, R.B.; Brinkmann, U.A.T. (1984): Chromatographic determination of phenylurea herbicides and their corresponding aniline degradation products in environmental samples. J. Chrom. 288, 71-90
[3] Clarke, E.A.; Anliker, R. (1980): Organic dyes and pigments. In: Handbook of Environmental Chemistry, Vol. 3A. Springer-Verlag, Heidelberg, 181-215
[4] Vogt, P.F.; Geralis, J.J. (1985): Aromatic amines. In: Ullmann´s Encyclopedia of Industrial Chemistry, Vol. A 2. VCH-Verlag, Weinheim, 37-56
[5] Haas, R.; v. Löw, E. (1986): Grundwasserbelastung durch eine Altlast. Die Folgen einer ehemaligen Sprengstoffproduktion für die heutige Trinkwassergewinnung. Forum Städte-Hygiene 37, 33-43
[6] Haas, R. (1985): Trennung, Nachweis und Bestimmung von Nitrotoluidinen. Forum Städte-Hygiene 36, 86-89
[7] Haas, R.; Schmidt, T.C.; Steinbach, K.; v. Löw, E. (1997): Methoden zur chemisch-analytischen Untersuchung von aromatischen Aminen nach Derivatisierung. gwf-Das Gas- und Wasserfach Wasser/Abwasser 138, 35-37
[8] Schmidt, T.C.; Leß, M.; Haas, R.; v. Löw, E.; Steinbach K. (1999): Determination of aromatic amines in ground and waste water by two new derivatization methods. Int. J. Environ. Anal. Chem., in print
[9] Schmidt, T.C.; Haas, R.; Steinbach, K.; v. Löw, E. (1997): Derivatization of aromatic amines for analysis in ammunition wastewater. I: Derivatisation via bromination of the aromatic ring. Fres. J. Anal. Chem. 357, 909-914
[10] Schmidt, T.C.; Haas, R.; v. Löw, E.; Steinbach, K. (1998): Derivatization of aromatic amines with bromine for improved gas chromatographic determination. Chromatographia 48, 436-442
[11] Haas, R.; Schmidt, T.C.; Steinbach, K.; v. Löw, E. (1997): Derivatization of aromatic amines for analysis in ammunition wastewater. II: Derivatization by iodination with a sandmeyer-like reaction. Fres. J. Anal. Chem. 359, 497-501
[12] Schmidt, T.C.; Leß, M.; Haas, R.; v. Löw, E.; Steinbach, K.; Stork, G. (1998): Gas chromatographic determination of aromatic amines in water samples after solid-phase extraction and derivatization with iodine. I.: Derivatization. J. Chrom. A 810, 161-172
[13] Haas, R.; Steih-Winkler, A.; Schmidt, T.C.; Steinbach, K.; v. Löw, E., Krippendorf, A. (1999): Grundwasserbelastung mit aromatischen Aminen durch Emissionen einer ehemaligen Mülldeponie. UWSF-Z. Umweltchem. Ökotox., in print
[14] Haas, R. (1998): 3 Reports about the investigation of aromatic amines in ground water near a waste disposal in Marburg/Hesse. unpublished