Stereoselective determination of R(−)- and S(+)-prilocaine in human serum using a brush-type chiral stationary phase, solid-phase extraction and UV detection

Abstract

A chiral HPLC method was developed for the quantitation of R(−)- and S(+)-prilocaine in human serum. The method involves sensitive and selective detection of R(−)- and S(+)-prilocaine using normal-phase chiral HPLC on a pirkle-type naphthyl ethylamine stationary phase (Sumichiral OA-4700, 250 mm × 4 mm i.d.) at ambient temperature with a flow rate of 0.8 ml min −1. A sample clean-up procedure was used for isolation of the analytes of interest from human serum using Bond-Elut C 18 columns with high recovery and selectivity. The detection limits were 4 ng ml − for R-prilocaine and 5 ng ml −1 for S-prilocaine. The limits of quantitation were 10 ng ml −1 for both enantiomers. Linear calibration curves in the 10–1000 ng ml −1 range showed good coefficients of determination >0.999 ( n − 3). Precision and accuracy of the method were 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.