Gas-liquid chromatography of amino acids

Engel, M. H. and P. E. Hare (1985), Gas liquid chromatography of amino acids and their derivatives, in Barrett, G. C. (ed.), Chemistry and Biochemistry of the Amino Acids, Chapman Hall, London, pp. 462-499. 

AI Ihekoronye. Quantitative gas-liquid chromatography of amino acids in enzymic hydrolysates of food proteins. J Sci Food Agric 36 1004-1012, 1985. 

G6. Gehrke, C. W., Roach, D., Zumwalt, R. W., Stalling, D. L., and Wall, L. L., Quantitative Gas-Liquid Chromatography of Amino Acids in Proteins and Biological Substances. Anal. Biochem. Lab., Columbia, Missouri, 1968. 

C. W. Gehrke, W. M. Lamkin, D. L. Stalling and L. L. Wall, Quantitative Gas—Liquid Chromatography of Amino Acids... 

Jaeger, H., H. U. Kloer, H. Ditschuneit, and H. Frank, Glass capillary gas-liquid chromatography of amino acids, in Applications of Glass Capillary Gas Chromatography (W. G. Jennings, ed.). Chromatography Science Series Vol. 15,331-364, Marcel Dekker, Inc., New York, 1981. 

Gas-Liquid Chromatography of Amino Acids in Biological Substances J. Chromatogr. 53(2) 171-194 (1970) CA 74 38994t... 

The resolution of optically active compounds by gas chromatography with chiral phases is a well-established procedure, and the separation of IV-perfluoro-acetylated amino acid ester enantiomers in 1967 was the first successful application of enantioselective gas-liquid chromatography [39] Amino acids have been resolved as their A-trifluoroacetyl esters on chiral diamide phases such as N-lauroyl-L-valine rerr-butylamide or iV-docosanoyl-L-valine fert-butylamide [40,41,... 

Relative to aspartic acid (amino acid analyzer). Mannose and glucosamine were estimated after Dowex 50 (H+)-catalyzed hydrolysis by gas liquid chromatography of glycitol acetate derivatives (26,27) enzymatically liberated mannose was estimated by omission oFthe hydrolysis step. 

Shahrokhi, F., and Gehrke, C. W., Quantitative gas-liquid chromatography of sulphur-containing amino acids. J. Chromatog. 36, 31-41 (1968). 

Gil-Av, D. Feibush, B. Charles-Sigler, R. Separation of enantiomers by gas liquid chromatography with anoptically active stationary phase. Tetrahedron Lett. 1988, 1009. Frank, H. Nicholson, GJ. Bayer, E. Rapid gas chromatographic separation of amino acid enantiomers with a novel chiral stationary phase. J. Chromatogr. Sci. 1974,15 (5), 174. 

A Micromethod for the Clinical Chemistry Routine Analysis of Amino Acids in Blood and Urine by Capillary Gas-Liquid Chromatography of Isobutyl Esters N(0)-Heptafluorobutyrare Derivatives... 

The great leap forward for chromatography was the seminal work of Martin and Synge (7) who in 1941 replaced countercurrent liquid-liquid extraction by partition chromatography for the analysis of amino acids from wool. Martin also realized that the mobile phase could be a gas rather than a liquid, and with James first developed (8) gas chromatography (GC) in 1951, following the gas-phase adsorption-chromatographic separations of Phillips (9). 

This chromalographic method is convenient and useful in a number of cases. Crystals of quartz which are chiral exhibit different adbsoptive power for several antipodes and so also starch has been employed. Gas-liquid chromatography (GIC) is also employed to resolve racemates. For example to separate racemic a amino acids they are converted into esters with optically active alcohols like (-)2 butanol or trifluroracetyl devivatives, which are then separated by GLC. 

Standard analytical procedures were used to evaluate the composition of ingredients. Of the proximate analyses, nitrogen, lipids, and crude fiber were measured by American Oil Chemists Society (AOCS) methods (12) and moisture and ash by Association of Official Analytical Chemists (AOAC) methods (13). Amino acid analyses were performed by gas-liquid chromatography (14) except for tryptophan, which was analyzed colormetrically Tl5). In addition to these assays, certain tests of ingredient safety or spoilage were also performed, which space does not permit to be reported in this paper, to assure that ingredients met accepted standards for food safety (16). 

FIGURE 4.8 Racemization tests employed for acquiring information on stereomutation. Couplings are carried out, and the isomeric content of the products is determined by a variety of techniques. AAA = amino acid analyzer GLC = gas-liquid chromatography. 

The identification and quantitation of the individual amino acids in a mixture is often required in metabolic studies and investigations of protein structure. The use of thin-layer chromatography or electrophoresis may be adequate to indicate the relative amounts and number of different amino acids in a sample but the use of gas-liquid chromatography or an amino acid analyser is essential for quantitative analysis. 

Derivatives of amino acids (Table 9.10) are required because amino acids are not themselves sufficiently volatile for gas-liquid chromatography and difficulties may be encountered in the choice and method of derivatization. In the past no single column was normally capable of resolving the derivatives of such a diverse group of compounds but the introduction of fused silica capillary columns has resulted in considerably improved resolution. 

Table 10.9 Derivatives of amino acids suitable for gas-liquid chromatography...

Isolation of individual amino acids started about 1820 by 1904 all of the naturally occurring amino acids in proteins had been isolated except methionine (Mueller, 1922) and threonine (Rose, 1937). One of the earliest methods for the separation of amino acids was through the differential volatility of their methyl or ethyl esters (Emil Fischer, 1901). This approach led to the discovery of valine, proline, and hydroxyproline. [In the 1970s Fischer s method was modified for microanalysis of proteins, separating the amino acid esters by gas phase chromatography. Separation is now usually performed by hplc (high pressure liquid chromatography).]... 

The enantiomeric purities of the (S)-amino acids were checked preparing the corresponding N-trifluoroacetylamino acid methyl esters, which are resolved into enantiomers by gas liquid chromatography on glass capillary... 

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