Chromatographic investigations of the configurational and geometrical isomerism of allylic N-terpenyl-N-hydroxyethyl-nitrosamines.

A preparative adsorption column chromatographic method is reported for the separation of cis and trans geometrical isomers of two types of N-nitrosamines derived from allylic terpenyl ethanolamines (experimental fish toxicants). Column eluates were monitored by gas chromatography in which a Carbowax 20M stationary phase was used. Further separation of E and Z configurational isomers was achieved by reversed-phase and normal-phase high-performance liquid chromatography. In the reversed-phase high-performance liquid chromatography system (acetonitrile-water), the 6',7'-acetylenic nitrosamines ( NMOA ) were efficiently resolved by using an argentous (AgNO3) mobile phase, whereas the presence of sodium alkanesulfonate in the aqueous acetonitrile mobile phase favored the base-line resolution of the 6',7'-olefinic nitrosamines ( NDOA ). For normal-phase separation on a silica column, addition of tetrahydrofuran to the mobile phase (methylene chloride-2-propanol) resulted in a varying degree of improvement in peak resolution (R) and column selectivity (alpha). Effects of temperature on the chromatographic behavior of the nitrosamine components are described. The high-performance liquid chromatographic separation method has proved to be applicable for the trace analysis of the title nitrosamines in organic tissues by way of thermal energy analysis.