expanded graphite
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Determination of Iopromide and Iopamidole in surface and waste waters was developed. A porous graphitic carbon sorbent was used for pre-concentration and separation of analytes, in combination with tandem mass spectrometry as detection technique. The method was validated and applied in routine analyses. Its characteristics such as repeatability, limits of detection and determination are presented together with evaluation of matrix effects. The working range was 20–1000 ng L–1, limit of determination 20 ng L–1 and expanded uncertainty 30 %.
- MeSH
- chemické látky znečišťující vodu * analýza MeSH
- chemické techniky analytické * MeSH
- hmotnostní spektrometrie MeSH
- johexol analogy a deriváty analýza MeSH
- kontrastní látky * analýza MeSH
- kyselina jothalamová analogy a deriváty analýza chemie MeSH
- kyseliny trijodbenzoové analýza chemie MeSH
- referenční standardy MeSH
- testování odbornosti laboratoří MeSH
- vysokoúčinná kapalinová chromatografie MeSH
Recently we showed the reduction and oxidation of six natural 2'-deoxynucleosides in the presence of the ambient oxygen using the very broad potential window of a pyrolytic graphite electrode (PGE). Using the same procedure, 2'-deoxynucleoside analogs (dNs) that are parts of an artificially expanded genetic information system (AEGIS) were analyzed. Seven of the eight tested AEGIS dNs provided specific signals (voltammetric redox peaks). These signals, described here for the first time, will be used in future work to analyze DNA built from expanded genetic alphabets, helping to further develop AEGIS technology and its applications. Comparison of the electrochemical behavior of unnatural dNs with the previously documented behaviors of natural dNs also provides insights into the mechanisms of their respective redox processes.
- Publikační typ
- časopisecké články MeSH
The design of smart surfaces with externally triggerable water/oil wettability and adhesion represents one of the most up-to-date challenges in the field of material science. In this work, the intelligent surface with electrically triggerable wettability and water/oil adhesion is presented. As a basic material background exhibiting electric field (EF) sensitivity, the piezo-responsive polymethylmethacrylate/polyvinylidenefluoride polymer fibers were used. To expand the available range of water/oil contact angles (CAs) and adhesion, the fibers were grafted with hydrophilic or hydrophobic functional groups using diazonium chemistry. The fiber functionality was evaluated using the static CA and wettability hysteresis measurements (increasing/decreasing drop volume and tilting angles), drops adhesion/repellence and graphite self-cleaning test performed with and without the application of EF. It was found that the proposed method enables tuning the surface wettability in the superhydrophobic/superoleophobic-hydrophilic/oleophilic range and changing of surface properties from low adhesive to high adhesive for water and oil. More convincing results were achieved in the case of fiber surface modification by ADT-C8F17, which may result from a rearrangement of the grated -C6H4C8F17 functional group under the application of EF triggering. Moreover, the triggering which can be performed in the extremely fast way (the surface responds to the EF switching on/off in seconds) was found to be fully reversible. Finally, the additional tests indicate the satisfactory stability of created fiber-based coating against the mechanical treatment.
