Validated HPLC–MS/MS method for determination of quetiapine in human plasma

A validated, highly sensitive and selective high-pressure liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was developed for the quantitative determination of quetiapine (QUE) in human Na2EDTA plasma with mass spectrometry (MS) detection. Clozapine (CLO) was employed as an internal standard. Samples were extracted using solid phase extraction (SPE). Oasis HLB cartridges and the concentration of quetiapine was determined by isocratic HPLC–MS/MS. The SRM mode was used for MS/MS detection. The method was validated over a concentration range of 1.0–382.2 ng/mL. Inter- and intra-day precision and accuracy of the proposed method were characterized by relative standard deviation (R.S.D.) and the percentage of deviation, respectively; both were lower than 8%. The developed method was employed in the pharmacokinetic study of quetiapine.