Non-enzymatic posttranslational modifications of bovine serum albumin (BSA) by oxo-compounds, particularly glucose, ribose, glyoxal and glutardialdehyde, have been investigated using a set of modern chromatographic and electrophoretic separation methods. High-performance liquid chromatography (HPLC) alternatively with UV spectrophotometric (diode array) or mass spectrometric (MS) detection, pol...

Different reversed-phase liquid chromatography (LC) columns of conventional dimensions were coupled to an ultraviolet photodiode array detector (UV-DAD) and a magnetic sector-type spectrometer, equipped with an electrospray ionization (ESI) source, by a laboratory-made flow splitter. A mixture of three flavonoid-O-glycosides was employed to examine the effects of the solvent composition, the fl...

Thermal lensing (TL) permits ultra-sensitive measurements of optical absorption of analytes in very small liquid volumes. We report the construction and use of a TL detector based on pulsed ultraviolet (UV) laser excitation (266 nm). We applied this detector to quantitate amino acids using capillary electrophoresis (CE) as a means of separation. Sixteen individual amino acids are readily detect...

The enantiomeric separation of three selenoamino acids, D,L-selenomethionine, D,L-selenoethionine and D,L-selenocystine is described. Both sulfated beta-cyclodextrin and vancomycin have been successfully used to separate all enantiomers of the compounds with UV detection. Reproducible separations, in terms of peak area and migration time were obtained using sulfated beta-cyclodextrin with rever...

Enantioseparation of amino acid analogues racemic β-amino alcohols has hitherto been thought impossible without prior derivatization. Method developers of chromatographic enantioseparation often face detection challenge due to low ultraviolet (UV) absorbance of these molecules. A new chiral derivatizing reagent, benzimidazole-(S)-naproxen amide, was synthesized to provide UV detectable chiral m...

Rapid detection of biologically active natural products plays a strategic role in the phytochemical investigation of crude plant extracts. In order to perform an efficient screening of the extracts, both biological assays and HPLC analysis with various detection methods are used. Combined techniques such as HPLC coupled to UV photodiode array detection (LC/UV) and to mass spectrometry (LC/MS or...

A highly sensitive and simple HPLC-UV method was developed and validated for the assay of glutathione (GSH) in PC-12 cells. Glutathione is a major intracellular antioxidant having multiple biological effects, best known for its cytoprotective effects against cell damage from reactive oxygen species and toxic reactive metabolites and regulating the cellular redox homeostasis. Due to its own sulf...

We investigated the application of two technologies for the fabrication of rectangular microchannels with reasonable path lengths for UV detection in UV transparent materials. The first approach uses inductively coupled plasma (ICP)–reactive ion etching (RIE) to fabricate channels in fused silica wafers, using a 4-mm-thick nickel layer as protective mask. The effects of the process parameters o...

A new methodology for the assessment of thiocyanate (SCN(-)) is proposed based on optical fiber (OF) detection coupled to a liquid chromatography system (LC). The developed methodology showed an adequate performance for the analysis of SCN(-) comparable to a high performance liquid chromatography with UV detector (HPLC-UV) methodology: a detection limit of 3 µg L(-1), a linear range from 4 to 4...

Aminoglycoside antibiotics can be determined by capillary zone electrophoresis (CZE) with indirect UV detection in the anionic mode with a reversed electroosmotic flow (EOF) by addition of FC 135 to the background electrolyte. The effective mobilities of thirteen aminoglycoside antibiotics were determined as a function of pH. Applying CZE with indirect UV detection in the anionic mode and rever...