@article{PereiraNascimentoMagalhaesetal.2014, author = {Pereira, Fernanda S. and Nascimento, Heliara D. L. and Magalhaes, Alvicler and Peter, Martin G. and Bataglion, Giovana Anceski and Eberlin, Marcos N. and Gonzalez, Eduardo R. P.}, title = {ESI(+)-MS and GC-MS study of the hydrolysis of N-azobenzyl derivatives of chitosan}, series = {Molecules}, volume = {19}, journal = {Molecules}, number = {11}, publisher = {MDPI}, address = {Basel}, issn = {1420-3049}, doi = {10.3390/molecules191117604}, pages = {17604 -- 17618}, year = {2014}, abstract = {New N-p-chloro-, N-p-bromo-, and N-p-nitrophenylazobenzylchitosan derivatives, as well as the corresponding azophenyl and azophenyl-p-sulfonic acids, were synthesized by coupling N-benzylvchitosan with aryl diazonium salts. The synthesized molecules were analyzed by UV-Vis, FT-IR, H-1-NMR and N-15-NMR spectroscopy. The capacity of copper chelation by these materials was studied by AAS. Chitosan and the derivatives were subjected to hydrolysis and the products were analyzed by ESI(+)-MS and GC-MS, confirming the formation of N-benzyl chitosan. Furthermore, the MS results indicate that a nucleophilic aromatic substitution (SnAr) reaction occurs under hydrolysis conditions, yielding chloroaniline from N-p-bromo-, and N-p-nitrophenylazo-benzylchitosan as well as bromoaniline from N-p-chloro-, and N-p-nitrophenylazobenzyl-chitosan.}, language = {en} } @article{StrehlauWeberLuerenbaumetal.2017, author = {Strehlau, Jenny and Weber, Till and Luerenbaum, Constantin and Bornhorst, Julia and Galla, Hans-Joachim and Schwerdtle, Tanja and Winter, Martin and Nowak, Sascha}, title = {Towards quantification of toxicity of lithium ion battery electrolytes - development and validation of a liquid-liquid extraction GC-MS method for the determination of organic carbonates in cell culture materials}, series = {Analytical and bioanalytical chemistry : a merger of Fresenius' journal of analytical chemistry, Analusis and Quimica analitica}, volume = {409}, journal = {Analytical and bioanalytical chemistry : a merger of Fresenius' journal of analytical chemistry, Analusis and Quimica analitica}, publisher = {Springer}, address = {Heidelberg}, issn = {1618-2642}, doi = {10.1007/s00216-017-0549-6}, pages = {6123 -- 6131}, year = {2017}, abstract = {A novel method based on liquid-liquid extraction with subsequent gas chromatography separation and mass spectrometric detection (GC-MS) for the quantification of organic carbonates in cell culture materials is presented. Method parameters including the choice of extraction solvent, of extraction method and of extraction time were optimised and the method was validated. The setup allowed for determination within a linear range of more than two orders of magnitude. The limits of detection (LODs) were between 0.0002 and 0.002 mmol/L and the repeatability precisions were in the range of 1.5-12.9\%. It could be shown that no matrix effects were present and recovery rates between 98 and 104\% were achieved. The methodology was applied to cell culture models incubated with commercial lithium ion battery (LIB) electrolytes to gain more insight into the potential toxic effects of these compounds. The stability of the organic carbonates in cell culture medium after incubation was studied. In a porcine model of the blood-cerebrospinal fluid (CSF) barrier, it could be shown that a transfer of organic carbonates into the brain facing compartment took place.}, language = {en} }