STEREOSELECTIVE DETERMINATION OF R(-)-PRILOCAINE AND S(-PRILOCAINE INHUMAN SERUM USING A BRUSH-TYPE CHIRAL STATIONARY-PHASE, SOLID-PHASE EXTRACTION AND UV DETECTION())

A chiral HPLC method was developed for the quantitation of R(-)- and S (+)-prilocaine in human serum. The method involves sensitive and selec tive detection of R(-)- and S(S)-prilocaine using normal-phase chiral HPLC on a pirkle-type naphthyl ethylamine stationary phase (Sumichiral OA-4700, 250 mm x 4 mm i.d.) at ambient temperature with a flow rate of 0.8 mi min(-1). A sample clean-up procedure was used for isolation of the analytes of interest from human serum using Bond-Elut C-18 colu mns with high recovery and selectivity. The detection limits were 4 ng ml(-1) for R-prilocaine and 5 ng ml(-1) for S-prilocaine. The limits of quantitation were 10 ng ml(-1) for both enantiomers. Linear calibra tion curves in the 10-1000 ng ml(-1) range showed good coefficients of determination > 0.999 (n = 3). Precision and accuracy of the method w ere within 4-5.8%; and 1.5-4.8% respectively for R(-)-prilocaine, and 2.8-5.7% and 3.2-5.2% respectively for S(+)-prilocaine.