Simultaneous Analysis of Hydrochlorothiazide, Triamterene and Reserpine in Rat Plasma by HPLC and DSPE

A dispersive solid-phase extraction (DSPE) method of mixing two different materials (C18 and MAX) was developed as extraction procedure, which provided better extraction yields (>82.1 %) for all analytes and more appropriate sample purification from endogenous interference materials compared with common SPE. Analyte separation was achieved on a C18 reversed phase column at the wavelength of 265 nm by high performance liquid chromatography (HPLC). The method was validated in terms of extraction yield, precision and accuracy. These assays gave mean accuracy values higher than 89 % with RSD values which were always less than 4.1 %. The method has a more simple operation process and achieves higher accuracy and precision than SPE. It has been successfully applied to plasma samples from rats after oral administration of target compounds.