Chromatographic retention relationships between aliphatic tertiary amines and their putative N-oxide metabolites--preliminary results.

The chromatography of a series of tertiary amines and the corresponding N-oxides have been studied and the Functional Group Contribution Approach used to describe retention correlations between them. Good correlations are observed between the behaviour of compounds on HPLC and with the exception of some alicyclic nitrogen compounds also on thin layer chromatography. The models produced are used to predict k' and Rf values for ranitidine N-oxide and tamoxifen N-oxide based upon those for the parent molecule. The deviation between actual and predicted values was larger than expected, presumably due to the structural or physico-chemical differences of ranitidine and tamoxifen compared to the model compounds.