Enantiomeric determination of L- and D-lactic acid in human cerebrospinal fluid by chiral ligand exchange high-performance liquid chromatography

Enantiomeric determination of L‐ and D‐lactate in human cerebrospinal fluid (CSF) was achieved by HPLC on a chiral stationary phase with UV detection. Samples were submitted to a solid‐phase extraction procedure using Oasis™ HLB Plus Extraction Cartridge and L‐ and D‐lactate in the extract were separated by Shodex ORpac CRX‐453 B column, a ligand exchange column for chiral separation, using a mobile phase containing copper (II) ion. L‐ and D‐lactate were determined in 25 min. Intra‐assay precision in CSF was 4.98% (mean 1.85 mmol/L) for L‐lactate and 10.1% (mean 4.96 µmol/L) for D‐lactate (n = 5). Detection limits were between 1.0 (L‐lactate) and 1.5 (D‐lactate) pmol. The mean values (n = 3) of analytical recovery for L‐ and D‐lactate were 95% and 107%, respectively. The mean ± SD of concentrations of L‐ and D‐lactate in CSF (n = 20) were 1.52 ± 0.54 mmol/L and 10.98 ± 5.15 µmol/L, respectively. Copyright © 2000 John Wiley & Sons, Ltd.