Simultaneous determination of imipramine and amitryptiline by derivative spectrophotometry.

Three methods are proposed for the simultaneous determination of imipramine and amitryptiline by derivative spectrophotometry, one of them using both first- and second-derivative spectra, and the others using the first- and second-derivative spectra, respectively, obtained from a "diode array" spectrophotometer. The methods allow the determination of 0.62-10.14 micrograms ml-1 of imipramine, and 0.63-10.04 micrograms ml-1 of amitryptiline, and have been applied to their determination in blood serum.