Validated chiral separation of M9, a Mannich ketone compound, by chiral ligand-exchange chromatography

Enantioseparation of the Mannich ketone M9, a potential antifungal compound, was examined using chiral ligand-exchange chromatography. The chiral mobile phase contained complexes of Cu(II) with the optically active selector L-aspartame (APM) and the organic modifier methanol. The separation was optimized with respect to the concentration of the Cu(II)-(L-APM) complexes, pH of mobile phase, methanol content, and column temperature. A baseline separation (R-s = 3.08) was achieved for enantiomers of M9 under optimal conditions, and the analysis was accomplished in eleven minutes. The developed method was extensively validated. The sample stability, linearity, precision (method repeatability and intermediate precision) and accuracy, and the limits of detection and quantification of the developed method were studied. The proposed method was shown to be accurate and suitable for the quantitative determination of each enantiomer of M9.