TY  - JOUR
A1  - Pereira, Fernanda S.
A1  - Nascimento, Heliara D. L.
A1  - Magalhaes, Alvicler
A1  - Peter, Martin G.
A1  - Bataglion, Giovana Anceski
A1  - Eberlin, Marcos N.
A1  - Gonzalez, Eduardo R. P.
T1  - ESI(+)-MS and GC-MS study of the hydrolysis of N-azobenzyl derivatives of chitosan
JF  - Molecules
N2  - 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.
KW  - chitosan
KW  - N-azobenzylchitosan
KW  - ESI-MS
KW  - GC-MS
KW  - SnAr reaction
Y1  - 2014
U6  - https://doi.org/10.3390/molecules191117604
SN  - 1420-3049
VL  - 19
IS  - 11
SP  - 17604
EP  - 17618
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Strehlau, Jenny
A1  - Weber, Till
A1  - Luerenbaum, Constantin
A1  - Bornhorst, Julia
A1  - Galla, Hans-Joachim
A1  - Schwerdtle, Tanja
A1  - Winter, Martin
A1  - Nowak, Sascha
T1  - 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
JF  - Analytical and bioanalytical chemistry : a merger of Fresenius' journal of analytical chemistry, Analusis and Quimica analitica
N2  - 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.
KW  - Liquid-liquid extraction
KW  - GC-MS
KW  - Lithiumion battery (LIB)
KW  - Organic carbonates
KW  - Cell culture materials
Y1  - 2017
U6  - https://doi.org/10.1007/s00216-017-0549-6
SN  - 1618-2642
SN  - 1618-2650
VL  - 409
SP  - 6123
EP  - 6131
PB  - Springer
CY  - Heidelberg
ER  -