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Originaltitel:
Method Development of Extraction and Enrichment of Noble Metal Nanoparticles in Environmental Water Samples 
Übersetzter Titel:
Trennung und Anreicherung von Edelmetall-Nanopartikeln aus Umweltproben 
Jahr:
2013 
Dokumenttyp:
Dissertation 
Institution:
Fakultät für Chemie 
Betreuer:
Schuster, Michael (Prof. Dr.) 
Gutachter:
Schuster, Michael (Prof. Dr.); Helmreich, Brigitte (Prof. Dr. habil.) 
Sprache:
en 
Fachgebiet:
CHE Chemie 
TU-Systematik:
CHE 216d; TEC 031d; UMW 151d 
Kurzfassung:
The increasing use of noble metal nanoparticles (NMNPs) in industrial and household applications has led to the release of NMNPs into the environment. Consequently, it is essential to understand their distribution and effects in environmental matrices. Moreover, quantitative analytical methods are also required to determine their environmental concentrations. However, practically nothing is known about their concentration, shape and size under environmental conditions due to the lack of analytical or pre-treatment methods for NMNPs in real environmental samples. In the present work, ligand-assisted liquid-liquid extraction method was investigated to extract and concentrate gold nanoparticles (Au-NPs). The 1-Dodecanethiol (DDT) was found the most efficient ligand for extraction of Au-NPs from water to n-hexane among four ligands namely DDT, 1-Octadecanethiol (ODT), dodecylamine (DDA) and octadecylamine (ODA). However, this ligand-assisted liquid-liquid extraction method was not applicable to extract Au-NPs at low concentration (< 100 µg/L). Hence, ligand-assisted solid-liquid extraction methods were developed. Two solid-liquid extraction methods using reversed-phase C18 (RP-C18) and ionic exchange resin (IRN-78) as adsorbent respectively were optimized to efficiently and selectively extract NMNPs (Au-NPs, Ag-NPs and Pd-NPs). Based on the optimized procedures, the extraction efficiencies and recoveries of NMNPs spiked into real environmental water samples were investigated, which demonstrated that both of the ligand-assisted solid-liquid extraction methods are applicable to extract NMNPs even at ng/L levels. Moreover, transmission electron microscopy (TEM) analysis confirmed that the size and shape of NMNPs could be preserved by these extraction methods. Finally, the solid(IRN-78)-liquid extraction method was used to extract nanoscale silver particles (n-Ag-Ps) from effluents of nine municipal wastewater treatment plants (WWTPs) in Germany. It shows that the concentrations of n-Ag-Ps in the field-collected effluents of WWTPs range from 2.2 to 9.4 ng/L. Moreover, based on the actual concentrations, we estimated that the daily n-Ag-Ps load entering water environment through effluent discharge (e.g., a WWTP with 520000 t/d treatment capacity) equates to about 4.4 g/d. 
Übersetzte Kurzfassung:
Der zunehmende Einsatz von Edelmetallnanopartikeln (NMNPs) im industriellen Umfeld und in Konsumprodukten hat zwangsläufig zu deren Freisetzung in die Umwelt geführt. Als Konsequenz daraus ist es unabdingbar, die Verteilung dieser Partikel in der Umwelt zu erfassen und die dort ausgelösten Effekte zu verstehen. Das erfordert neue analytische Methoden zur Anreicherung und Vorkonzentrierung der Partikel aus realen Matrices, die bisher aber nicht existieren. Aus diesem Grund ist praktisch nichts üb...    »
 
Mündliche Prüfung:
17.07.2013 
Dateigröße:
2525954 bytes 
Seiten:
108 
Letzte Änderung:
25.11.2013