Small-Scale Two-Dimensional LC for a Preparative Re-Purification of a Highly Labile Tritium-Labelled Compound.

Tritium-labelled compounds are generally less stable than their non-labelled counterparts. This requires storage at low temperatures, a constant workflow of quality checks and subsequent re-purifications. As the amount of tritium-labelled material is typically purified in the μg range, repeated injections on analytical-scale UHPLC systems can provide high resolution re-purification results. Yet, degradants can be undesirably included in the compound isolation since the amount of decomposition can vary dramatically depending on the structure. We report a case of a sensitive molecule which could not be isolated in pure form even though the chromatographic separation was successful. In this case, the use of a small-scale two-dimensional preparative LC approach with a direct transfer interface to a second (trapping) column resulted in a highly pure compound (>98% HPLC). This approach combines high chromatographic resolution, accurate control over the re-purification process, minimal sample manipulation, and higher overall safety for handling of radioactive samples.