title: Improved clean-up procedure for the high-performance liquid chromatographic assay of bupivacaine enantiomers in human plasma and ultrafiltrate in the nanogram per milliliter range.
abstract: A clean-up procedure to obtain a minimal detectable concentration of 5-10 ng bupivacaine enantiomer per milliliter human plasma is described. The procedure consists of precipitation of plasma proteins using acetonitrile, followed by solid-phase extraction using a cyano column. The eluate is then made alkaline, and bupivacaine is extracted using n-hexane. After evaporation of n-hexane, the residue is redissolved in the eluent used for HPLC analysis. The HPLC method has been described previously. The minimal detectable concentrations using this method are ca. 8 and 10 ng/ml for R-(+)- and S-(-)-bupivacaine, respectively. For both enantiomers, r2 is > 0.995 over the range of 9.5-760 ng/ml enantiomer.
authors.affiliation: National Institute of Public Health and Environmental Protection, Bilthoven, Netherlands.
authors.forename: K
authors.initials: K
authors.lastname: Groen
authors.forename: P W
authors.initials: PW
authors.lastname: Zeijlmans
authors.forename: A G
authors.initials: AG
authors.lastname: Burm
authors.forename: J W
authors.initials: JW
authors.lastname: van Kleef
mesh_terms: D002045:Bupivacaine / Q000097:blood*; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007275:Injections, Intravenous; D013237:Stereoisomerism; D014462:Ultrafiltration
chemical_list: D002045:Bupivacaine