Analysis of Cimetidine in Biological Fluids by High Performance Liquid Chromatography

Abstract
The clean-up and analysis of cimetidine in human urine and blood is described. Samples were prepared by adsorption on Waters Sep-pak C-18 disposable pre-columns in basic solution followed by elution in 1 ml methanol. For blood samples, the eluate was concentrated under a stream of nitrogen; urine samples required no further concentration. The separation was performed on a reversed phase column using a mixture of methanol-1 mM sodium dodecyl sulphate in a 10 mM phosphate buffer of pH 3.0 (35:65) as mobile phase. Procaine was used as internal standard. Detection was by UV at 228 nm yielding a minimum detectable quantity of 20 ng with linearity over three decades of concentration.