Enantiomeric purity determination of acetyl-L-carnitine by reversed-phase high-performance liquid chromatography using chiral derivatization

An indirect HPLC enantioseparation method for the determination of acetyl-D -carnitine (D-AC) in acetyl-L-carnitine (L-AC) was developed. L-AC was deri vatized with a chiral amino compound which has a chromophore for UV detecti on. Six chiral amino compounds were examined as chiral derivatization reage nts. Among them, enantiomers of acetylcarnitine derivatized with L-alanine- beta-naphthylamide (L-Ala-beta-NA) were successfully separated on an ODS co lumn within 10 min with R-s = 1.94 and alpha = 1.10. Quantitation was achie ved through UV detection at 254 nm. The derivatization reaction of L-AC wit h L-Ala-beta-NA was completed in less than 10 min at room temperature (ca. 20 degrees C). Validation data such as linearity, detection limit, and prec ision are also presented. The detection limit of D-AC in L-AC in this metho d was below 0.05% (visual evaluation). This method was found to be applicab le as a practical quality control method for the enantiomeric purity determ ination of L-AC. (C) 1999 Elsevier Science B.V. All rights reserved.