Purification of non-toxic, biodegradable arginine-based gemini surfactants, bis(Args), by ion exchange chromatography

This paper presents an environmentally improved procedure for the preparati ve purification of a series of arginine-based gemini surfactants. The techn ique used was cation-exchange chromatography, Mixtures of boric-borate buff er, co-solvent (ethanol), and sodium chloride were tested as eluents. The i nfluence of the buffer pH and the amount of co-solvent on the chromatograph ic process was studied for the model compound bis(N-alpha-lauroyl-L-arginin e)1,3-propanediamide dihydrochloride, C-3(LA)(2), and purification conditio ns were established. The method was scaled-up to the multigram. level for C -3(LA)(2) and the rest of the series. The proposed preparative procedure in volves simple equipment, low cost materials, and minimal amounts of solvent (water/ethanol), with low toxicity.