Reversed-phase high performance liquid chromatographic determination of cyproheptadine from urine by solid-phase...

A simple, sensitive and reliable high-performance liquid chromatographic method for the determination of cyproheptadine in urine by solid-phase extraction (SPE) has been developed. The sample matrix was passed through a pre-conditioned C18 cartridge, washed with methanol-water solution (4:1) and eluted with methanol. The methanolic solution was evaporated to dryness, reconstituted with methanol and chromatographed using a C18 reversed-phase column. The mobile phase consisted of acetate buffer (constant ionic strength of 0.005 I)-methanol (56:44, v/v). Detection was performed at 254 nm with the sensitivity set at 0.002 AUFS. Concentrations as low as 50 ng/ml could be quantitatively determined by an external standard method and the overall recovery was found to be 76.16%, whereas the limit of detection was estimated as 15 ng/ml.