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Electrochemical Analysis of Carrageenans. The Effect of Acetate Concentration
Kos, S.S. ; Paleček, Emil
kappa-, iota-, and lambda-carrageenans are polysaccharides (PSs) which produce electrocatalytic chronopotentiometric peak H-ps in acetate buffer (pH 5.2) on the hanging mercury drop electrode (HMDE). Here we show that this peak (E-p1.8V) increases with the acetate concentration Using a. c. voltammetry we found that the appearance and the observed increase of peak H-PS is accompanied by a decrease of capacitive current below the background elecnolyte around1.8 V, suggesting strong adsorption of the negatively charged PS at the negatively charged HMDE. Compared to carrageenany dextran did not produce peak H-PS and did not strongly adsorb at negatively charged electrode.
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CE-nESI/MS in electrode-free design: narrowing the separation channel to 5 μm
Týčová, Anna ; Foret, František
Capillary electrophoresis-nanospray/mass spectrometry (CE-nESI/MS) in electrodefree\narrangement represents a very simple instrumentation for analysis of biomolecules.\nSo far, CE-nESI/MS analyses in this design were limited to 10-75 μm ID of the\nseparation channel. Although the work with narrower dimensions brings several\nchallenges, there is a great potential for better sensitivity, improved separation power\nand lower sample consumption. This work is devoted to some practical aspects of\nexperiments in narrow bore channels and systematic evaluation of CE-nESI/MS\nanalyses conducted in capillaries of 25, 15 and 5 μm ID.
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