Cyanamide and its derivatives which were formed in the manufacture of dicj andiamide were chromatographed with 1-butanol-ethyl alcohol-water (4 : 1 : 1) and with methyl ethll ketone-petroleum ether-water (9:4:3) on Whatman No. 3 and No. 3MM filter paper. Sixteen spots were detected on the chromatograms; cyanourea, biguanide, melamine, three salts of guanidine, urea, guanylthiourea, thiocyanate, thiourea, dicyandiamide, and cyanamide were characterized. Quantitative analysis for urea gave a recovery of 957'.URIKG the manufacture of dicyandiamide from cyanamide, D by-product formation occurs from the reaction of these substances with water or with impurities introduced into the reaction mixture from the raw material. In a continuous process, these by-products and their decomposition products are allowed t o remain in the system, and further reaction may occur slowly R ith cyanamide and diryandiamide to consume further amounts of both substances.Much effort has been devoted to the development of methods of analysis of the compounds likely to be formed (6, f4), but these procedures as well as unpublished modifications of them have yielded results of questionable accuracy. The use of paper chromatography as an aid in studying the nature and quantities of these compounds in solutions of unknown composition has not been reported, although the development of urea, guanidine, and guanidine derivatives on paper chromatograms has been described (1-3, 10, 12). When the work reported here n-as neaily complete, it came to the authors' attention that Hubener and others ( 7 ) had quantitatively determined urea on paper chromatograms. Measurements of urea involved the addition of p-diniethylaminobenzaldehyde t o the chromatogram to form a yellow complex which was eluted with pyridine and measured spectrophotometrically a t 449 mp. This procedure was modified recently by Bode and Ludwig (5).
EXPERIMEYTALApparatus. Borosilicate glass chromatography jars with paper support racks and solvent assemblies, and a Chromatocab were purchased from the Schaar Co., Chicago.Reagents were sprayed on the developed chromatograms with a laboratory constructed glass atomizer.A Beckman Model D U spectrophotometer with Corex cells of 1.002-em. light path was used for the urea determinations. The slit width was kept constant at 0.16 mm.Developing Solvents. Numerous solvent mixtures consisting of various combinations of 1-butanol, methyl ethyl ketone, ethyl alcohol, water, petroleum ether, ammonia, and acetic acid were tested as the mobile phase on Whatman No. 3 filter paper. This paper was used because of its high capacity for solids. The paper was not prewashed and the chromatograms were developed over a temperature range of a t least &so C. from room temperature without any noticeable change in the resolution of the various cyanamide derivatives. The solvent which gave the best separation of most of the compounds was a solution of l-butanolethyl alcohol-mater (4: 1 : l ) . The organic layer of a mixture of methyl ethyl ketone-petroleum ether-water (...
