AbstractA new procedure for indirect determination of pharmaceutical drugs is presented. The procedure consists of extracting ion pairs between organic basic compounds, that is, pharmaceutical drugs and cobalt tetrathiocyanate and of determining Co contents in the organic extraction phase using total reflection X-ray fluorescence spectrometry. Quinine, papaverine and pilocarpine are used as pharmaceutical drugs and 1,2-dichloroethane is adopted as extraction medium. Quinine cobalt tetrathiocyanate complex was isolated and was analyzed by FT-IR (Fourier Transform Infra-Red spectroscopy) suggested that approximately 4 ng of quinine could be detected by 1 μl of sampling of organic phase under ideal conditions using total reflection X-ray fluorescence spectrometry. These drugs have their own optimal pH for extraction. This technique can be applied to cocaine analysis.
