ENANTIOMERIC SEPARATION AND DETECTION OF 2-ARYLPROPIONIC ACIDS DERIVATIZED WITH [(N,N-DIMETHYLAMINO)SULFONYL]BENZOFURAZAN REAGENTS ON A MODIFIED CELLULOSE STATIONARY-PHASE BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

(RS)-2-Arylpropionic acids (2-APAs) were derivatized with the fluoroge nic reagents, lamino)sulfonyl]-7-piperazino-2,1,3-benzoxadiazole (DBD- PZ) and [N,N-(dimethylamino)sulfonyl]-2,1,3-benzoxadiazole (DBD-COHz), and their enantiomeric separation by a chiral stationary phase high-p erformance liquid chromatography was investigated in the reversed-phas e mode with H2O/CH3CN or H2O/MeOH as the mobile phase on a column of c ellulose tris(3,5-dimethylphenyl carbamate) coated on a silica gel sup port (Chiralcel OD-R). The derivatives with DBD-PZ were enantiomerical ly separated well under the elution condition of H2O/MeOH, based on th e pi-pi interaction between the derivatives and the stationary phase. The rigid and bulky structure of DBD-PZ was demonstrated to be more ef fective as compared to the less rigid ones. The derivatives with DBD-C OHz were more efficiently separated into each enantiomer with H2O/CH3- CN as the eluent. The effective separation was based on hydrogen-bondi ng interaction between the acid hydrazide of the derivatives and the c arbamoyl moiety of the stationary phase, There was a reversal in the e lution order of the enantiomers between the two fluorescent derivative s. The detection limits obtained for each enantiomer were approrrimate ly 10-30 fmol on column. The derivatization with the reagent and the c oncomitant use of the reversed-phase and chiral stationary-phase HPLC were demonstrated to be useful for the enantiomeric quantification in rat plasma after intravenous administration of flurbiprofen racemate, a representative of 2-APAs.