Enantioseparation of α,α-diphenyl-2-pyrrolidinemethanol (D2PM) and methylphenidate (MPH; Ritalin) using (R)-(-)-4-(N,N-dimethylaminosulfonyl)- 7-(3-isothiocyanatopyrrolidin-1-yl)-2,1,3-benzoxadiazole as the chiral derivatization reagent has been achieved for the first time, and a simple, reliable detection method using HPLC with fluorescence detection has been developed. D2PM and MPH have been derivatized with (R)-(-)-4-(N,N- dimethylaminosulfonyl)-7-(3-isothiocyanatopyrrolidin-1-yl)-2,1,3-benzoxadiazole at 55°C for 15 min. The derivatives of D2PM and MPH have been separated, completely and rapidly, using a reversed-phase system within 16 min (resolution factor (Rs)=1.60 and 2.53, respectively). The detection limits of (R)-and (S)-D2PM were found to be 6.8 and 13 ng/mL, respectively, and those of D-and L-threo-MPH were 61 and 66 ng/mL, respectively (S/N=3). The proposed method was successfully applied to the analysis of rat plasma, where the rats were separately dosed with D2PM and MPH (Ritalin).
- Fluorescence detection