Determination of cyanamide in plasma by high-performance liquid chromatography.

A sensitive, selective and rapid high-performance liquid chromatographic procedure was developed for the determination of cyanamide in plasma. The procedure involved extraction with ethyl acetate, derivatization with 5-(dimethylamino)naphthalene-1-sulphonyl chloride and posterior analysis by high-performance liquid chromatography on a mu Bondapak C18 column with fluorimetric detection. Linearity ranged from 5 to 500 ng/ml and the lower limit of sensitivity of the assay was 4 ng/ml of cyanamide in plasma. The precision of the method was 3.0-8.9%, expressed as relative standard deviation over the linear range. This method has been used to elucidate the time course of the cyanamide concentration in the plasma of humans, following oral administration of cyanamide at therapeutic doses.