Abstract: A reversed-phase HPLC method for simultaneous determination of amitriptyline,doxepin,trimipramine,clomipramine,inipramine and their major metabolites despramine in human whole blood was described. The method involved the use of acetanilideas and as internal standard. Blood samples were extracted at basic pH with he-cane: isoamyl(99∶1,V/V) followed by back extraction into 0.1 mol/L sulfuric acid, Thechromatographic separation was accomplished with amobile phase comprising acetonitrile - aqueous solution containing 0.01mol/L potassium dihydrogenphosphate and 0. 01 mol/L diethlamine with phosphoric acid adjusted to pH 3. 0 (2∶8,V/V).The mobile phase was pumped at flow rate 2. 0 ml/min.The column used Hypersil C18. Detection isachieved at 210nm, the lower limit of sensitivity was 10ng/ml. The recoveries of tricyclic antidepressants was 58.4 - 107. 6%'the coefficients of variation to within-daywas 1. 78-10. 07% and day to day was 3. 01 -11.05 %.This method is suitable in forensic toxicology analysis and TDM for tricyclic antidepressants.

Key words: RP-HPLC method, whole blood, determination of the tricylic antidepressant