In vitro study of enzymatic hydrolysis of diperodon enantiomers in blood serum by two-dimensional LC.

An on-line coupled HPLC system is described for the determination of the enantiomers of diperodon in blood serum. The method involves three steps: (i) off-line preconcentration and clean-up, (ii) separation of the diperodon enantiomers from the matrix components on a reversed-phase stationary phase, and (iii) separation of the racemate from the reversed-phase column on a teicoplanin chiral stationary phase. The method is suitable for simultaneous determination of both enantiomers in serum up to 0.5 microg/ml. The degradation of diperodon enantiomers was studied in serum by an in vitro method and the experimental rate constants were determined. The enantiomeric hydrolysis rates and half-lives for diperodon in serum are different.