High-performance liquid chromatographic assay of mepivacaine enantiomers in human plasma in the nanogram per milliliter range.
A method enabling quantification of R-(-)- and S-(+)-mepivacaine in human plasma in the low nanogram per milliliter range is described. The procedure involves extraction from plasma with diethyl ether, centrifugation, back-extraction into an acidified aqueous solution, washing with a mixture of pentane and isoamylalcohol, alkalinisation, followed by extraction with a mixture of n-pentane and isoamylalcohol. After evaporation of the organic phase, the residue is redissolved in the mobile phase used for the HPLC analysis, which consists of a 6.8:93.2 (v/v) isopropanol-sodium hydrogenphosphate buffer solution with the pH adjusted to 6.8 using phosphoric acid. The HPLC method has been described previously. Separation of the enantiomers is achieved with an alpha 1-AGP column and the UV detection wavelength is 210 nm. The minimal detectable concentration is ca. 3 ng/ml and the lower limit of quantification is 5 ng/ml for each enantiomer. For both enantiomers r is > 0.9995 over the plasma enantiomeric concentration range of 10.5-1053 ng/ml.
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A A
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University Hospital Leiden, Department of Anaesthesiology, The Netherlands.
Olieman
W
W
Burm
A G
AG
Groen
K
K
van Kleef
J W
JW
D000779:Anesthetics, Local / Q000097:blood*; D002851:Chromatography, High Pressure Liquid / Q000379:methods* / Q000706:statistics & numerical data; D006801:Humans; D008619:Mepivacaine / Q000097:blood*; D008832:Microchemistry; D012044:Regression Analysis; D013237:Stereoisomerism
D000779:Anesthetics, Local; D008619:Mepivacaine