Isotopic separations of tritium-substituted compounds from protium analogues by high-pressure liquid chromatography

Abstract

The use of high-pressure liquid chromatography (HPLC) for the separation of a large variety of compounds is now common. Those compounds which contain hydrophobic moieties can often be well separated on reverse phase columns where the stationary hydrocarbon phase is bound to the support and the compounds are eluted with water, mixed with polar organic solvents such as methanol. One of the advantages of HPLC is the high column efficiency which can be obtained. Despite this, however, it may still not be possible to resolve certain closely related compounds, such as the 12 phenols of benzo[ a]pyrene (BP) (1,2). Thus, when identity between a radioactive component and its unlabeled analogue is to be claimed, great care must be exercised. We were concerned, therefore, when, during an investigation (3) of products formed by the enzyme-catalysed binding of 7,12-[G- 3H]dimethylbenz[ a]anthracene (DMBA) to polyguanosine, some of the modified nucleoside adducts showed very slightly shorter retention times than the unlabelled compound to which it was thought they corresponded. the possibility that this was an isotopic separation (4) was investigated.