Eberhard von Löw

Gas chromatographic determination of aromatic amines in water samples after solid-phase extraction and derivatization with iodine: I. Derivatization

A procedure for the enrichment of aromatic amines via solid-phase extraction was developed. A HR-P phase based on styrene-divinylbenzene was used for the investigations, generally followed by derivatization with iodine and determination via GC-ECD. The recoveries of 53 aromatic amines in a drinking water matrix at pH 9 were determined. Most anilines showed relative recoveries between 80-120% with relative standard deviations of< or = 5% at concentration levels between 10 and 20 micrograms 1(-1). The comparison with a wastewater matrix led to similar results. The enrichment procedure was applied to real samples, e.g., samples of ammunition wastewater.

Conception for the investigation of contaminated munition plants

SummaryA report is given of the photometric and gaschromatographic determination of RDX-explosive mixtures. The application of these analytical methods is shown by two examples.

Mass balance studies with 14C-labeled 2,4,6-trinitrotoluene (TNT) mediated by an Anaerobic desulfovibrio species and an Aerobic serratia species.

Abstract. Investigations were carried out to evaluate the level of incorporation of radiolabeled 2,4,6-trinitrotoluene (TNT) and metabolites into the bacterial biomass of two different bacterial species after cometabolically mediated TNT transformation. Biotransformation experiments with 14C-TNT indicated that TNT was not mineralized; however, carbon derived from TNT became associated with the cells. It was found that more than 42% of the initially applied radiolabel was associated with the cell biomass after cometabolic 14C-TNT transformation with the strictly anerobic Desulfovibrio species strain SHV, whereas with the strictly aerobic Serratia plymuthica species strain B7, 32% of cell-associated 14C activity was measured. The remainder of the radiolabel was present in the supernatants of the liquid cultures in the form of different TNT metabolites. Under anoxic conditions with the Desulfovibrio species, TNT was ultimately transformed to 2,4,6-triaminotoluene (TAT) and both diaminonitrotoluene isomers, whereas under oxic conditions with the Serratia species, TNT was converted to hydroxylaminodinitrotoluenes and aminodinitrotoluenes, with 4-amino-2,6-dinitrotoluene (4ADNT) being the major end product. In both culture supernatants, small amounts of very polar, radiolabeled, but unidentified metabolites were detected. At the end of the experiments approximately 92% and 96% of the originally applied radioactivity was recovered in the studies with the Serratia and Desulfovibrio species, respectively.

Anaerobic incorporation of the radiolabeled explosive TNT and metabolites into the organic soil matrix of contaminated soil after different treatment procedures.

Four bioreactor designs were performed to evaluate the level of incorporation of 14C-labeled 2,4,6-trinitrotoluene (TNT) and metabolites into the organic soil matrix of different anaerobically treated contaminated soils. The contaminated soils were amended with molasses slivers (80:20% per weight) as auxiliary substrate to enhance microbial activity. After 5 weeks (bioreactors 1 and 2), 8 weeks (bioreactor 3) and 12 weeks (bioreactor 4) of anaerobic incubation, we determined 41%, 58%, 72%, and 54%, respectively, of the initially applied radioactivity immobilized in various soil fractions. After alkaline hydrolyses of the solvent-extracted soils, low quantities of radiolabel were found in the humic and fulvic acid fractions, whereas the bulk of 14C activity was found to be strongly bound to the humin fraction (solid soil residues). The amounts of solvent extractable radioactivity were 53%, 40%, 16%, and 29% for bioreactors 1, 2, 3, and 4, respectively. The level of TNT transformation at the end of the experiments was within 90-94%. Regarding the results presented in this study, we can assume that there is the possibility of high incorporation levels of TNT metabolites into the soil organic matrix mediated by microbial cometabolism under strictly anoxic conditions.

Identification of Oxidized TNT Metabolites in Soil Samples of a Former Ammunition Plant

Water extracts of soil samples of the former ammunition plant “Tanne” near Clausthal-Zellerfeld, Lower Saxony, Germany, were investigated for highly polar oxidized 2,4,6-trinitrotoluene (TNT) metabolites. 0.4 to 9.0 mg/kg dry soil 2,4,6-trinitrobenzoic acid (TNBA) and 5.8 to 544 mg/kg dry soil 2-amino-4,6-dinitrobenzoic acid (2-ADNBA) were found. In addition to the oxidized metabolites, TNT, 4- and 2-aminodinitrotoluene (4- and 2-ADNT), and 2,4-dinitrotoluene (2,4-DNT) were extractable with water. Most interestingly, in one sample, 2-ADNBA represented the main contaminant.The origin of the oxidized nitroaromatics is unknown at this time. They might be generated chemically or photochemically. Furthermore, a biological synthesis seems possible.

Highly polar metabolites of nitroaromatic compounds in ammunition wastewater.

Transformation processes of nitroaromatic compounds (NAC) are described that lead to polar and highly hydrophilic metabolites in ammunition waste water. For the identification of proposed metabolites, several analytical methods for the separation and determination of these compounds were developed and applied to the investigation of a former ammunition plant and its surroundings. The compound classes which were investigated include nitro and amino substituted toluenesulfonic acids, nitrobenzoic acids, aminobenzoic acids and nitromethylphenols. Method development was usually done with high performance liquid chromatography and ion pairing or ion suppression techniques. In the leachate water of a disposal site of a former ammunition plant in Stadtallendorf, Germany, 15 compounds from the above-mentioned categories have been found to be present in concentrations up to a few hundred microgram/L. The presence of so many polar compounds suggest that current and future surveying programs should include representative analytes of the investigated categories.

Determination of Aromatic Amines in Ground and Waste Water by Two New Derivatization Methods

Abstract Two derivatization methods for aromatic amines are presented that are based on the halogenation of the aromatic ring. Bromination yields brominated anilines, in which all hydrogens in ortho- and para-positions are replaced by bromine via an electrophilic substitution. In contrast, iodination yields the corresponding iodobenzenes, in which all amino groups are substituted by iodine. Separation of at least 30 derivatives in a single gaschromatographic run in 30 min is possible with each method. Detection in routine analysis was done with an electron capture detector, but some findings with GC-MS and GC with atomic emission detection are also presented. Both methods were applied to real samples of different origin and the results are compared. In industrial wastewater and ground water from a landfill and a former ammunition plant, about 20 aromatic amines were found to be present in the μg/L concentration range. In the case of the former ammunition plant, most analytes observed were degradation prod...

Post-column photochemical conversion of aromatic amines

SummaryThis study presents UV spectral data for 39 aromatic amines and 3 nitroaromatic compounds and examines the influence on the compounds of short-term irradiation at 254 nm. It also gives some general characteristics of the UV spectra of irradiated and non-irradiated analytes. It was ascettained that nitro or aminonitro compounds are photochemically much more stable than aromatic amines without nitro substituents. Other substituents, for example −OH,−COOH,−SO3H, and −CH3, do not increase the photochemical stability. Therefore, the alteration of the UV spectra for the latter compounds can be used as an additional criterion for identification; this is shown with waste water from the site of a former ammunition plant as an example.

Chemisch-analytische Untersuchung von Arsenkampfstoffen und ihren Metaboliten

ZusammenfassungArsenkampfstoffe sind in der Umwelt persistent und kontaminieren bis heute Boden und Grundwasser. In diesem Beitrag werden die chemischen Reaktionen der Arsenkamptstoffe Diphenylarsinchlorid (CLARK I), Phenylarsindichlorid (PFIFFIKUS), Ethylarsindichlorid (DICK) sowie von Chlorvinylarsinverbindungen (LEWISITE) dargestellt. Die Möglichkeiten der chemisch-analytischen Erfassung dieser chemischen Kampfstoffe als Originalsubstanzen und als Thiol-Derivate werden präsentiert.AbstractArsenic containing chemical warfare agents (cwa) are persistent in the environment and continue to contaminte soil and ground water. In this paper the chemical rections of the cwa diphenylarsine chloride (CLARK I), phenylarsine dichloride (PFIFFIKUS), ethylarsine dichloride (DICK) and of chlorovinyl arsenic compounds (LEWISITE) are shown. The posibilities of the detection and determination of this cwa and their metabolites are presented.

Mikrobielle Sanierung von 2,4,6-Trinitrotoluol (TNT) kontaminierten Böden

ZusammenfassungIm Rahmen einer Durchführbarkeitsstudie zuon-site-Sanierungen von Böden, die mit TNT (2,4,6-Trinitrotoluol) kontaminiert sind, wurde die Kompostierung als eine vielversprechende und kostengünstige Methode näher untersucht und mit der vorhandenen Literatur, vor allem in Hinblick auf ökotoxikologische Risiken, kritisch verglichen. Standort ist die ehemalige TNT-Produktionsstätte «Werk Tanne» bei Clausthal-Zellerfeld in Niedersachsen. Zur ersten Einschätzung der autochtonen Mikroflora wurden Untersuchungen zur Zahl der vorhandenen acroben heterotrophen Bakterien und ihrer Atmungsaktivität im Boden durchgeführt. Ferner wurden Mikroorganismen aus dem Boden isoliert und auf ihre Fähigkeit, TNTin vitro zu metabolisieren, näher untersucht. Sowohl die Anzahl der autochtonen Mikroorganismen (4,7×108 his 1,2×1010 koloniebildende Einheiten (KBE)/kg Trockengewicht (TG)) als auch deren Atmungsaktivität zeigte keinerlei Korrelation zur gefundenen Nitrotoluolkonzentration im Boden. Mit hoch kontaminiertem Boden (20 g TNT/kg TG) wurde eine Kleinkompostierung im 10 Liter-Maßstab durchgeführt, in deren Verlauf die TNT-Menge innerhalb von 28 Tagen um mehr als 90% abnahm und nur geringe Mengen Monoaminodinitrotoluole gebildet wurden. Ein Säureaufschluß des anfallenden Kompostmaterials zeigte jedoch, daß TNT unter diesen Bedingungen teilweise wieder herauslösbar ist und ein ökotoxikologisches Risiko daher weiterhin bestehen könnte. Mögliche Prozeßänderungen des Kompostierungsverfahrens zur sicheren Festlegung der Kontaminanten in der Humusmatrix werden diskutiert.AbstractWithin the limits of a feasability study abouton-site bioremediation methods for TNT-contaminated soils, composting was chosen as a very promising and cheap method. This method was critically compared with those described in the literature and was primarily rated under ecotoxicological aspects. The investigated location is the former munition plant «Tanne» in the aerea of Clausthal-Zellerfeld in Lower Saxony, Germany. To estimate the autochtonic microflora, we assessed the number of aerobic heterotrophic bacteria and determined their respiration activity in soils. In addition, we isolated bacteria and examined their capacity to metabolize TNTin vitro. Both the amount of autochtonic microrganisms (4.7×108 to 1.2×1010 colony forming units (cfu)/kg dryweight) as well as their respiration activity did not correlate with the concentrations of nitrotoluenes in the soils. With high contaminated soil (20 g TNT/kg dry weight) we carried out a small compost in the range of 10 liters. During 28 days of composting TNT-concentration decrease over 90% and only minor amounts of monoaminodinitrotoluenes were generated. However, an acidic pretreatment of the compost material at the end of the reaction showed that TNT could be partially resolved under these extreme conditions and that an ecotoxicological risk may still exist. Possible changes in the realization of the composting process in order to make sure that the contaminants are savely bound to the humin matrix are discussed.