Abstract
Thin-layer chromatography (TLC) of fifteen amino acids was performed using silica gel and alumina impregnated with micellar solutions of cetrimide and cetylpyridinium chloride as stationary phases and aqueous solutions of dextrose as mobile phases. TLC system comprising of silica gel impregnated with micellar solution of cetrimide (5.0 mM) as stationary phase and 40% (w/v) aqueous solution of dextrose as mobile phase was found the most favourable for the separation of amino acids. Impregnation of silica gel with the micellar solution of cetrimide brings about a substantial change in the mobility of lysine. Separation of lysine (ketogenic) from arginine (glucogenic) is important physiologically. Surface modification of silica gel on impregnation, as indicated by FTIR and SEM studies, was responsible for improved chromatographic performance. The effect on the separation of the presence in the sample of heavy metal cations, as impurities, was examined. Limits of detection for lysine and arginine were 0.17 mu g and 0.12 mu g, respectively. For validation, the stability of the mixture and the reproducibility of the chromatographic properties Delta R-F, separation factor(k), and resolution (R-s) were calculated. The proposed method is simple, rapid, and free from use of volatile organic solvents.