Separation of thiols as phenyl mercury derivatives by thin-layer chromatography. I. Azathioprine and 6-mercaptopurine metabolites.

A method is described for converting thiol metabolites of azathioprine and 6-mercaptopurine into phenyl mercury derivatives. Separation of these derivatives was performed by chromatography on silica thin layers and they were detected by low temperature (--196 degrees) fluorescence. The parent compounds were regenerated on the chromatogram by spraying with 2 N HC1 and these were detected by low temperature fluorescence. Mercury was also detected in spots by spraying with dithizone. The method provides a simple solution to the problem of oxidation of thiol compounds during isolation procedures.