Enantiomeric determination of D- and L-lactate in rat serum using high-performance liquid chromatography with a cellulose-type chiral stationary phase and fluorescence detection.

A method is described for the quantitative determination of d- and L-lactate in 10 microl of rat serum, which includes fluorescence derivatization of D- and L-lactate with 4-(N, N-dimethylaminosulfonyl)-7-piperazino-2,1,3- benzoxadiazole (DBD-PZ) followed by O-acetylation. The derivatives are separated by HPLC on an octadecylsilica, and, via column switching, on a cellulose-type chiral column. Levulinic acid was used as the internal standard. The enantiomers of lactate were separated with the separation factor (alpha) of 1.27 and the resolution (Rs) of 2.72, while the linearity for the detection was over the range of 10 nmol/ml to 20 micromol/ml (r = 0.999). Interday precision values for D-lactate in rat serum were 5.8, 5.3, and 4.1% for 10, 100, and 1000 nmol/ml, and accuracy values were 109.6, 98.2, and 103.1%, respectively (n = 5). The reduction of d-lactate concentration in rat serum by fasting was observed with the method. Copyright 1999 Academic Press.