Ion-exchange separation and automated assay of complex mixtures of amino acids and some hexosamines

Abstract Moore's and Stein's classical ion-exchange separation of amino acids remains the standard by which all methods are judged. The adaptation of liquid chromatography (LC) equipment to amino acid analysis was inevitable because microprocessor control of gradients allowed almost infinite variation in gradient shape, producing superior resolution with only 2 buffers. The versatility of LC equipment allowed the instruments to be used for other assays. Adaptation of orthophthalaldehyde (OPA) to amino acid analysis increased detection sensitivity to the picomole range. A method for essential amino acids analysis in mechanically separated red meat and poultry products has been adapted to liquid chromatography using postcolumn hypochlorite oxidation, OPA derivatization, and fluorescence detection. Separation is achieved with 2 sequential concave exponential gradients combining ionic strength and pH increases with halidecontaining buffers. Hydroxyproline and proline are detected with increasing sensitivity through the use of 3-mercaptopropionic acid in a stabilized OPA reagent. Sample preparation is a critical part of the method. A defatting procedure removes fat and other nonprotein nitrogenous substances. The hydrolysis procedure is designed to protect tryptophan which can be routinely assayed in hydrolysates with a modified flow program. Corrosion damage to the equipment by halide buffers has brought about a search for alternative methodology.

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Ion-exchange separation of titanium from steels and its determination with hydrogen peroxide

Analytica Chimica Acta ◽

10.1016/s0003-2670(01)81355-6 ◽

1960 ◽

Vol 23 ◽

pp. 438-440 ◽

Cited By ~ 2

Author(s):

V ATHAVALE ◽

M NAPKARNI ◽

C VENKATESWARLU

Keyword(s):

Hydrogen Peroxide ◽

Ion Exchange ◽

Ion Exchange Separation

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PAPER CHROMATOGRAPHY OF COMPLEX BIOLOGICAL MATERIALS BY SOLVENT REDEVELOPMENT WITHOUT PRIOR REMOVAL OF SALTS OR PROTEINS

Canadian Journal of Biochemistry and Physiology ◽

10.1139/o60-141 ◽

1960 ◽

Vol 38 (10) ◽

pp. 1137-1147 ◽

Cited By ~ 12

Author(s):

Arthur E. Pasieka

Keyword(s):

Amino Acids ◽

Paper Chromatography ◽

Filter Paper ◽

Complex Mixtures ◽

Two Dimensional ◽

One Dimensional ◽

Equivalent Time ◽

Biological Compounds ◽

High Concentrations ◽

Subsequent Staining

A solvent redeveloping technique has been devised by which amino acids, peptides, and sugars can be separated from complex mixtures in the presence of high concentrations of salts and proteins. The separations are effected by two to four successive 18-hour solvent developments with drying between each 18-hour period before subsequent staining of the chromatograms. Better separations and resolutions are obtained by such successive 18-hour solvent developments than by one continuous solvent development for an equivalent time. The effect of these redevelopments on the separations and resolutions of biological compounds is illustrated at various stages by photographs of one- and two-dimensional chromatograms. The redevelopment technique requires filter paper sheets up to 4 ft in length for one-dimensional analytical and preparative types of chromatograms.

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