Impurities & Reference Standards

Impurities & Reference Standards collects environmental contaminants, industrial chemicals and drug stereoisomers. Many entries are substances monitored in environmental and food analysis, such as the plasticizer dimethyl phthalate and the polycyclic aromatic hydrocarbon fluorene. Flame retardants are represented by the organophosphate triphenyl phosphate and by brominated compounds. Perfluorodecanoic acid belongs to the per- and polyfluoroalkyl substances (PFAS), a class known for persistence in the environment. A second group holds enantiomers and isomers of research compounds, such as (R)-Asundexian, the (R)-enantiomer of the factor XIa inhibitor asundexian. Such isomers support stereochemical comparison and the development of chromatographic separation methods. Process-related and degradation compounds of individual drugs are listed separately under Drug Impurity.