LIQUID-CHROMATOGRAPHY THERMOSPRAY MASS-SPECTROMETRY OF TOREMIFENE ANDITS DERIVATIVES

A high-performance liquid chromatographic-thermospray mass spectrometr ic method was developed for analysis of toremifene and eight of its de rivatives, including some main metabolites. The compounds were chromat ographed with an acetonitrile-ammonium acetate buffer eluent. Thermosp ray mass spectra of the compounds, showing abundant protonated molecul ar ions, were obtained with the exception of deaminohydroxy- and deami nocarboxy-toremifene, which apparently did not get protonated under th ese conditions. Selected-ion monitoring (SIM) of the protonated molecu lar ion of toremifene; die molecule of main interest in this series, w as accomplished. According to the results, toremifene can be analyzed in the range from 0.01 mu g/ml to 10 mu g/ml, the limit of detection b eing 500 pg per injection. This method provides an effective means for purity assignation of forthcoming synthetic triphenylethylene derivat ives. Liquid chromatography-thermospray mass spectrometry with selecte d-ion monitoring seems to be a sensitive and a selective quantitation method for toremifene.