Determination of telmisartan in rat tissues by in-tube solid-phase microextraction coupled to high performance liquid...

A poly(methacrylic acid-ethylene glycol dimethacrylate, MAA-EGDMA) monolithic capillary was used for the direct and on-line extraction of telmisartan from Sprague-Dawley rat tissue (heart, kidney, and liver) homogenates. Under optimized conditions, the tissue homogenates were simply diluted with a mixture of phosphate buffer (pH 2)/ACN (90:8 v/v), and then injected for extraction only after centrifugation and filtration. Coupled to HPLC with fluorescence detection, the method was linear over the range of 1.25-1500 ng/g for telmisartan in heart and kidney, 12.5-15 000 ng/g in liver with correlation coefficients over 0.9992. The detection limits were found to be in the range from 0.24 to 1.8 ng/g. RSDs for intra- and inter-day ranged from 1.2 to 8.1%. The determination of telmisartan in treated rat tissues was achieved by using the proposed method.