A rapid and sensitive method for determination of sorafenib in human plasma using a liquid chromatography/tandem mass spectrometry assay

A rapid, sensitive and specific method was developed and validated using LC/MS/MS for determination of sorafenib in human plasma. Sample preparation involved a single protein precipitation step by the addition of 0.1 mL of plasma with 0.5 mL acetonitrile. Analysis of the compounds of interest including the internal standard ([H-2(8) N-15] sorafenib) was achieved on a Waters X-Terra (TM) C-18 (150 mm x 2.1 mm i.d., 3.5 mu m) analytical column using a mobile phase consisting of acetonitrile/10mM ammonium acetate (65:35, v/v) containing 0.1% formic acid and isocratic flow at 0.2 mL/min for 6 min. The analytes were monitored by tandem mass spectrometry with electrospray positive ionization. Linear calibration curves were generated over the range of 7.3-7260 ng/mL for the human plasma samples with values for the coefficient of determination of > 0.96. The values for both within day and between day precision and accuracy were well within the generally accepted criteria for analytical methods (< 15%). (c) 2006 Elsevier B.V. All rights reserved.