Quantitative ¹H and ¹³C NMR and Chemometric Assessment of ¹³C NMR Data: Application to Anabolic Steroid Formulations

This study investigates the potential of ¹H and ¹³C NMR for the characterization and classification of anabolic androgenic steroids (AASs) in various formulations. First, twenty AAS formulations, including tablets, capsules, and injectable solutions, were analyzed using ¹H NMR for the qualitative identification and quantification of active compounds. The results revealed discrepancies between the labeled and detected substances in several samples, highlighting issues related to product mislabeling and potential health risks. Then, twelve oil-based injectable formulations were examined using ¹³C NMR, demonstrating its effectiveness in differentiating and quantifying closely related steroid structures that cannot be discriminated with ¹H NMR. A chemometric approach from ¹³C NMR data, based on a principal component analysis (PCA) and hierarchical cluster analysis (HCA), enabled the classification of samples and the identification of key active ingredients.