Fig. 2. The HPLC traces (blue trace, UV detection; black trace, radiodetection of ¹⁴C by scintillation counting of fractions) obtained for the analysis of a mixture of radiolabeled (rac)-¹⁴C-2′-nicotine (14) with unlabeled (S)-nicotine (14). The first peak in the radiochromatogram is the selective detection of labeled enantiopure (S)-14 while the second peak is the selective detection of a scalemic mixture of labeled 14. The first clear peak in the UV-based HPLC trace is a mixture of labeled and unlabeled enantiopure (S)-14 while the second indistinct peak overlapped with the first is a mixture of labeled and unlabeled “racemic” 14 (actually scalemic but tending to racemic and the ee of the unlabeled 14 arising from the enantiopure 14 and the labeled 14 is not the same as the ee of the labeled 14 originating from the labeled 14). The following conditions were applied for the HPLC: column, Partisil PXS CSX; eluent, 0.12 M AcONa–MeOH (75 : 25); pH, 6.8; flow rate, 2.0 mL min^–1.