High‐performance liquid chromatographic enantioseparation of ( R , S )‐fluoxetine using Marfey's reagent and ( S )‐ N ‐(4‐nitrophenoxycarbonyl) phenylalanine methoxyethyl ester as chiral derivatizing reagents along with direct thin‐layer chromatographic resolution and isolation of enantiomers using l ‐tartaric acid as mobile phase additive

Chiral assay of enantiomers of fluoxetine was achieved in pharmaceutical formulations using direct and indirect methods. l ‐Tartaric acid was used as a mobile phase additive in thin‐layer chromatography; the enantiomers were separated and isolated and were used to determine the elution order in HPLC. ( R , S )‐flouxetine was derivatized with ( S )‐ N ‐(4‐nitrophenoxycarbonyl)phenylalanine methoxyethyl ester [( S )‐NIFE], Marfey's reagent and 1‐fluoro‐2,4‐dinitrophenyl‐ l ‐methionine amide (FDNP‐ l ‐Met‐NH 2 ). The diastereomers were separated using RP‐HPLC. The effect of flow rate and TFA concentration on resolution was studied. The diastereomers obtained by derivatization with FDNP‐ l ‐Met‐NH 2 were also separated by RP‐TLC. Copyright © 2010 John Wiley & Sons, Ltd.