On-chip intermediate LED-IF-based detection for the control of electromigration in multichannel networks.

Monitoring analytes during the transfer step from the first to the second dimension in multidimensional electrophoretic separations is crucial to determine and control the optimal time point for sample transfer and thus to avoid band broadening or unwanted splitting of the sample band with consequent sample loss. A spatially resolved intermediate on-chip LED-induced fluorescence detection system was successfully implemented for a hybrid capillary-chip glass interface. The setup includes a high-power 455-nm LED prototype as an excitation light source and a linear light fiber array consisting of 23 light fibers with a diameter of 100 μm for spatially resolved fluorescence detection in combination with a push-broom imager for hyperspectral detection.

Zero-dead-volume interfaces for two-dimensional electrophoretic separations.

We present the study on the sample transfer characteristics of two different microfluidic interfaces for 2D-CE . These interfaces were manufactured using two different microfabrication technologies: one was obtained via the classical photolithography-wet etching-anodic-bonding process; and the other was obtained via the selective laser-induced etching process. The comparison of the two interfaces, and an intact capillary as a reference, was made via the CE separation of amino acids (arginine and lysine) under different bulk flow conditions, with and without applying bias potential to the secondary channels.

Structure characterization of unexpected covalent O-sulfonation and ion-pairing on an extremely hydrophilic peptide with CE-MS and FT-ICR-MS.

In this study, we characterized unexpected side-products in a commercially synthesized peptide with the sequence RPRTRLHTHRNR. This so-called peptide D3 was selected by mirror phage display against low molecular weight amyloid-β-peptide (Aβ) associated with Alzheimer's disease. Capillary electrophoresis (CE) was the method of choice for structure analysis because the extreme hydrophilicity of the peptide did not allow reversed-phase liquid chromatography (RPLC) and hydrophilic interaction stationary phases (HILIC).

Column-coupling strategies for multidimensional electrophoretic separation techniques.

Multidimensional electrophoretic separations represent one of the most common strategies for dealing with the analysis of complex samples. In recent years we have been witnessing the explosive growth of separation techniques for the analysis of complex samples in applications ranging from life sciences to industry. In this sense, electrophoretic separations offer several strategic advantages such as excellent separation efficiency, different methods with a broad range of separation mechanisms, and low liquid consumption generating less waste effluents and lower costs per analysis, among others.

Bioconversion of car-3-ene by a dioxygenase of Pleurotus sapidus.

Mycelium of the basidiomycete Pleurotus sapidus known to contain a novel dioxygenase was used for the bioconversion of car-3-ene [I]. After 4h of incubation 25.3mgL(-1) car-3-en-5-one [V], 5.

Determination of ammonium, calcium, magnesium, potassium and sodium in drinking waters by capillary zone electrophoresis on a column-coupling chip.

This work deals with simultaneous determination of ammonium, calcium, magnesium, sodium and potassium in drinking waters by capillary zone electrophoresis (CZE) on a column-coupling (CC) chip with suppressed hydrodynamic and electroosmotic transports. CZE separations were carried out in a propionate background electrolyte at a low pH (3.2) containing 18-crown-6-ether (18-crown-6) to reach a complete resolution of the cations.