Siluveru M, Stewart J T
Department of Medicinal Chemistry, College of Pharmacy, University of Georgia, Athens 30602-2352, USA.
J Pharm Biomed Anal. 1997 Jul;15(11):1751-6. doi: 10.1016/s0731-7085(96)01968-1.
A high performance capillary electrophoresis assay for the quantitative determination of R(+) and S(-) mepivacaine in human serum is reported using heptakis (2,6-di-O-methyl) beta-cyclodextrin as the chiral selector for the separation of the enantiomers. The background electrolyte was a 100 mM phosphate buffer (pH 2.5) containing 20 mM heptakis (2,6-di-O-methyl) beta-cyclodextrin and 30 nM hexadecyltrimethylammonium bromide (HTAB). A 72 cm uncoated fused silica capillary was used for the analysis. HTAB was used as the buffer additive to decrease the adsorption of endogenous substances onto the silica wall. To separate the analytes of interest from the endogenous serum substances, a liquid-liquid extraction procedure was used. The extraction recoveries were greater than 70% for both R(+) and S(-) mepivacaine. The detection limits were around 150 ng ml-1 using 1 ml of serum and the limits of quantitation were 200 ng ml-1. The calibration curves were linear over a range of 200-2000 ng ml-1 with R(-) prilocaine as internal standard (IS) and coefficients of determination were greater than 0.999 (n=3). Precision and accuracy of the method were 4.1-7.2 and 2.6-5.9%, respectively, for R(+) mepivacaine and 4.0-7.4 and 3.2-7.4% for respectively, for S(-) mepivacaine. The HPCE method was compared to an existing HPLC method in terms of sensitivity and selectivity for the routine analysis of the drugs.
报道了一种高效毛细管电泳法，用于定量测定人血清中的R(+)和S(-)甲哌卡因。该方法使用七(2,6-二-O-甲基)β-环糊精作为手性选择剂来分离对映体。背景电解质是含有20 mM七(2,6-二-O-甲基)β-环糊精和30 nM十六烷基三甲基溴化铵(HTAB)的100 mM磷酸盐缓冲液(pH 2.5)。使用一根72 cm的未涂层熔融石英毛细管进行分析。HTAB用作缓冲添加剂，以减少内源性物质在硅胶壁上的吸附。为了将目标分析物与内源性血清物质分离，采用了液-液萃取程序。R(+)和S(-)甲哌卡因的萃取回收率均大于70%。使用1 ml血清时，检测限约为150 ng ml-1，定量限为200 ng ml-1。以R(-)丙胺卡因作为内标(IS)，校准曲线在200-2000 ng ml-1范围内呈线性，测定系数大于0.999(n = 3)。该方法对R(+)甲哌卡因的精密度和准确度分别为4.1-7.2%和2.6-5.9%，对S(-)甲哌卡因的精密度和准确度分别为4.0-7.4%和3.2-7.4%。在药物的常规分析中，将该高效毛细管电泳法与现有的高效液相色谱法在灵敏度和选择性方面进行了比较。
