Enantiomer Labeling Research Articles

Glass capillary gas chromatography of amino acid enantiomers

AbstractGlass capillaries coated with Chirasil‐Val, a chirally functionalised polysiloxane, are capable in principle of resolving all protein amino‐acid enantiomers in a single run and within a short analysis time, thus allowing for example the quantitative amino acid determination by enantiomer labelling. The elution characteristics of the individual amino acids however are also dependent upon the chemical nature of the capillary wall surface, and a surface pretreatment is found to be necessary if all protein amino acids are to be analysed. Of the various methods of pretreatment tested, etching of borosilicate glass with gaseous HCl followed by deposition of colloidal silicic acid is considered to be the most suitable.

Enantiomer labelling, a method for the quantitative analysis of amino acids

Enantiomer labelling, a method for the quantitative analysis of opticaly active natural compounds by gas chromatography, involves theuse of the unnatural enantiomer as an internal standard. WithChirasil-Val, a chiral stationary phase that is thermally stable up to up to 240°, the enantiomers of amino acid and a variety of other compounds can be separated and quantitated. Incomplete recovery from the sample, incomplete derivatization, hydrolysis and thermal decomposition of the derivative and shifting response factors can be compensated for by adding the unnatural enantiomer. The accuracy of amino acid analysis by enantiomer labelling is equal or superior to that of hitherto known methods. The procedure affords a complete analysis of peptides with respect to both amino acid composition and the optical purity of each amino acid.