Separation data is usually limited to the mere assessment of whether the analyte retention time could fit in the range of the candidate's chemical class. To take better advantage of the LC data, retention times are required to be initially converted to retention indices (r i ), since the former are significantly influenced by the chromatography conditions, such as temperature, mobile phase composition, and gradients. On the other hand, r i values provide a robust and highly reproducible way to express retention in liquid chromatography. High reproducibility makes inter-laboratory results comparable, enabling both m/z and r i comparison with a reference and resulting in more confident suspect shortlisting.