Determination of Serum Creatinine by Ion Exchange Chromatography and Ultraviolet Spectrophotometry

Thin-layer chromatography of guanidino compounds

Twelve guanidino compounds including, among others, glycocyamine, creatine, creatinine, arginine, guanidinosuccinic acid were submitted to thin-layer chromatography on plates precoated with silica gel or cellulose, respectively. Optimal resolution was obtained by two-dimensional chromatography on cellulose layers when the two solvent systems iso-propanol-acetic acid-water (volumes, 60 ml + 45 ml + 15 ml) and iso-propanol-dimethyl-formamide-water (volumes, 40 ml + 20 ml + 20 ml) were used for the first and second dimension, respectively. This procedure permitted the resolution of 10 distinct spots out of a mixture of the twelve guanidino compounds. Chloroform-methanol-ammonia (170 g/kg) (volumes, 40 ml + 20 ml + 20 ml) proved to be the most suitable solvent system for one-dimensional chromatography on cellulose layers of less complex mixtures of guanidino compounds.

[Separation of guanidino compounds by means of ion-exchange thin-layer chromatography (author's transl)]

Thirteen guanidino compounds including glycocyamine, glycocyamidine, creatine, creatinine, arginine and guanidinosuccinic acid were chromatographed on thin-layer plates pre-coated with ion-exchange resins. Maximum resolution was obtained on layers of the cation-exchange resin eluted with 0.12 M sodium citrate buffer of pH 5.2, permitting the separation of nine of the thirteen guanidino compounds. Relationships between structure and physiochemical properties and the elution patterns of some selected guanidines were graphically evaluated.