Confusion between dimethyl selenenyl sulfide and dimethyl selenone released by bacteria

Dimethyl selenone [(CH 3 ) 2 SeO 2 ] has been reported in the literature as a metabolite released by bacteria in contact with selenium metal or selenium salts. In this study, mass spectral, chromatographic, and boiling‐point data are presented that show that dimethyl selenone has been confused with dimethyl selenenyl sulfide (CH 3 SeSCH 3 ). In addition, the headspaces above monocultures of selenium‐resistant bacteria were examined using gas chromatography followed by fluorine‐induced chemiluminescence detection. A number of alkyl sulfur and selenium species were detected, along with dimethyl selenenyl sulfide. A pathway from oxidized selenium salts to reduced methylated selenides and dimethyl selenenyl sulfide is also presented.