HPLC assay for guanidine salts based on pre-column derivatization with acetylacetone

A specific, isocratic HPLC assay procedure for guanidine hydrochloride is developed. A key step in the procedure, pre-column derivatization with acetylacetone, is performed under conditions that permit direct injection of the reaction mixture onto an HPLC column. Specific directions for carrying out the derivatization are given and the effects of reaction variables are discussed. In addition, chromatographic conditions are given for the separation of the derivative formed from other components of the reaction mixture. The derivatization also is demonstrated to be applicable to guanidine carbonate, nitrate, and sulfate.