Analytik aromatischer Amine in wässrigen und biologischen Matrices. Neue Verfahren zur Anreicherung und selektiven Detektion
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Philipps-Universität Marburg
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Abstract
Aromatic amines are an important class of pollutants due to their wide spread and high toxicity. The enrichment that is required for trace analysis is difficult due to the polarity of the amino compounds. For this reason, a derivatization method was developed consisting of a diazotisation of the aromatic amines directly in an aqueous solution and the conversion to aromatic iodine compounds by addition of iodide. The polarity of the analytes decreases on average by two orders of magnitude per amino group as measured by the octanol-water partition coefficients. Therefore even polar aromatic amines can be enriched by solid-phase microextraction (SPME).
The method is applicable to a broad range of aromatic amines that can be derivatized and analysed simultaneously. Apart from alkylated and halogenated amines the derivatization is also suitable for deactivated nitrated and dinitrated anilines and diamino compounds. Liquid and gas chromatography were both used for the separation of the derivatives that are stable in aqueous solution for several weeks.
For GC-MS analysis the limits of detection of the investigated aromatic amines were in the lower ng/L range. The detection in the fullscan-mode permitted an unequivocal verification of the target compounds as well as a general non-target analysis for aromatic amines. A sample volume of only 10 mL was sufficient for a sensitive determination so that biological matrices are also accessible. Despite the additional derivatization the reproducibility was comparable with those of established methods for the analysis of aromatic amines. The developed in-situ derivatization SPME GC-MS method was successfully applied to the determination of aromatic amines in contaminated groundwater at the site of a former ammunition plant.
The iodine compounds were detected selectively after gas-chromatographic separation by an element-selective atomic-emission detector (GC-AED), providing a powerful screening method even for unknown aromatic amines after derivatization. By this method aromatic amines were easily traced in the runoff-water of a former ammunition plant, without any interference by matrix components or iodinated reaction products.
The method transfer to complex matrices required the extraction from the headspace to protect the SPME-fiber. For most derivatives the sensitivity and reproducibility of HS-SPME was even improved compared to direct extraction. The equilibrium is reached quickly, so that after only 25 min the extraction of many analytes is carried out under equilibrium conditions.
The in-situ derivatization SPME method was applied to urine to give an comprehensive overview of the occurring aromatic amines. After acidic hydrolysis and derivatization numerous iodine compounds were found in the urine of smokers. The derivatization proved to be highly selective since even in such a complex matrix exclusively the derivatives of aromatic amines were detected. Thus, GC-AED measurements were not inferred by natural iodine compounds or aliphatic amines that also form iodine derivatives so that the exposure to aromatic amines can be easily judged. For urine samples of smokers and passive smokers only slight differences were found, whereas in the urine of nonsmokers without known exposure to cigarette smoke significantly less compounds were found.
By parallel atomic-emission and mass-spectrometric detection with GC-AED/MS for each iodine signal a mass spectrum of the related derivative was assigned. Finally the number of known aromatic amines in urine could be remarkably extended. By in-situ derivatization SPME GC-MS in the urine of a smoking person more than 200 aromatic amines were identified as iodinated derivatives. Most of them were alkylated or chlorinated anilines. For the first time several alkylated homologues of aminobiphenyls and naphthylamines have been found. Furthermore, the method was used to identify the more polar diamino compounds and aminophenols in urine. At the same time, some nitrogen-substituted aminopyridines and aminoquinolines occurred.
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Created: 2005Issued: 2005-12-13Updated: 2011-08-10
Faculty
Fachbereich Chemie
Publisher
Philipps-Universität Marburg
Language
ger
Data types
DoctoralThesis
Keywords
UrinAromatische AmineDerivatizationSolid-phase microextractionUrineAromatic aminesMass spectrometry
DFG-subjects
FestphasenmikroextraktionHPLCDerivatisierungHarn ,KörperflüssigkeitGC-MSMassenspektrometrieArylamineAtomemissionsspektroskopie
DDC-Numbers
540
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Zimmermann, Thomas (108920496): Analytik aromatischer Amine in wässrigen und biologischen Matrices. Neue Verfahren zur Anreicherung und selektiven Detektion. : Philipps-Universität Marburg 2005-12-13. DOI: https://doi.org/10.17192/z2005.0626.
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This item has been published with the following license: In Copyright