Energy-Resolved Fragmentation Aiding the Structure Elucidation of Steroid Biomarkers.

The identification and confirmation of steroid sulfate metabolites in biological samples are essential to various fields, including anti-doping analysis and clinical sciences. Ultra-high-performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) is the leading method for the detection of intact steroid conjugates in biofluids, but because of the inherent complexity of biological samples and the low concentration of many targets of interest, metabolite identification based solely on mass spectrometry remains a major challenge. The confirmation of new metabolites typically depends on a comparison with synthetically derived reference materials that encompass a range of possible conjugation sites and stereochemistries.

Synthesis of stable isotope labelled steroid bis(sulfate) conjugates and their behaviour in collision induced dissociation experiments.

Steroid bis(sulfate) metabolites derived from the two-fold sulfation of unconjugated precursors represent an important yet understudied portion of the steroid profile. The investigation of these compounds in fields such as medicine or anti-doping science relies on mass spectrometry (MS) as the principal tool to identify and quantify biomarkers of interest and depends in turn on access to steroid reference materials and their stable isotope labelled (SIL) derivatives. A new [O] stable isotope label for sulfate metabolites is reported, which allows for the selective, late-stage and 'one-pot' synthesis of a variety of SIL-steroid conjugates suitable as MS probes and internal standards.