Amino acid analysis by capillary electrophoresis electrospray ionization mass spectrometry.

A method for the determination of underivatized amino acids based on capillary electrophoresis coupled to electrospray ionization mass spectrometry (CE-ESI-MS) is described. To analyze free amino acids simultaneously a low acidic pH condition was used to confer positive charge on whole amino acids. The choice of the electrolyte and its concentration influenced resolution and peak shape of the amino acids, and 1 M formic acid was selected as the optimal electrolyte.

Simultaneous determination of monosaccharides in glycoproteins by capillary electrophoresis.

A rapid, easy, and reproducible capillary electrophoretic method for the simultaneous determination of acidic, neutral, and amino sugars and sugar alcohols was developed. Underivatized mannuronic acid, glucuronic acid, galacturonic acid, N-glycolylneuraminic acid, N-acetylneuraminic acid, glucosamine, galactosamine, mannose, xylose, glucose, galactose, fucose, ribose, mannitol, sorbitol, xylitol, and inositol were simultaneously determined with indirect UV detection using 2,6-pyridinedicarboxylic acid as a background electrolyte. A highly alkaline pH condition was used in order to charge carbohydrates negatively and to promote migration toward the anode.

Sequence dependent migration behavior of double-stranded DNA in capillary electrophoresis.

Capillary electrophoresis (CE) with a replaceable linear polyacrylamide (LPA) sieving matrix was used to examine sequence-dependent migration of double-stranded DNA fragments. It has been found that DNA conformational effects were significant under high electric field separations, especially using high resolution matrices. Compared to linear DNA-ladder standards, both anomalously slow and rapid DNA fragments were observed, with the degree of anomalous migration depending on the electric field strength, polymer concentration, column temperature, and background electrolyte (denaturants, sodium and magnesium ions, DNA-intercalating dyes).

Diode array detection in capillary electrophoresis.

Diode array detection (DAD) in capillary electrophoresis (CE) offers similar advantages over single-wavelength detection as it does in high performance liquid chromatography (HPLC). Thus, confirmation of compound identity and establishment of peak purity are critical issues in CE, necessitating sensitive and specific detection. With an optimized optical system, DAD yields sensitivity comparable to that of single or variable wavelength detectors.