Lensmeyer G L, Kempf T, Gidal B E, Wiebe D A
Department of Pathology, School of Pharmacy, University of Wisconsin Hospital and Clinics, Madison 53792, USA.
Ther Drug Monit. 1995 Jun;17(3):251-8.
The anticonvulsant drug gabapentin and its heptaneacetic acid analog-used here as an internal standard--are isolated from serum (pH 9) with an octyldecyl (C-18) solid-phase sorbent column. To enhance analytical detection, trinitrobenzene derivatives of these extracted compounds are prepared quickly within 10 min. To further improve chromatographic selectivity, the derivatives are concentrated on a thin C-18 solid-phase membrane and interferences are washed away. The retained purified derivatives are eluted from the membrane with a small volume of solvent and the eluate is directly injected onto an Ultrasphere C-18 high-performance liquid chromatography column with quantification at 340 nm. No evaporation-concentration steps are necessary. Recoveries (extraction) of gabapentin and the internal standard are 94.2 +/- 2.9% and 98 +/- 2.0%, respectively. Analytical responses are linear from lower limit of sensitivity of 0.05 mg/L up to at least 10 mg/L. Between-run coefficients of variation (CV) range from 2.3 to 2.9% through the concentration range 0.5-4.0 mg/L. To illustrate the rationale for selection of test parameters for a robust method, we present optimization graphs for these processes. Moreover, we discuss the advantage of the packed cartridge and membrane sorbens as companion extraction devices.
抗惊厥药物加巴喷丁及其庚烷乙酸类似物（用作内标），通过十八烷基（C-18）固相吸附柱从血清（pH 9）中分离出来。为提高分析检测能力，在10分钟内快速制备这些萃取化合物的三硝基苯衍生物。为进一步提高色谱选择性，将衍生物浓缩在薄的C-18固相膜上，并洗去干扰物。保留的纯化衍生物用少量溶剂从膜上洗脱，洗脱液直接注入到超球C-18高效液相色谱柱中，在340nm处进行定量分析。无需蒸发浓缩步骤。加巴喷丁和内标的回收率（萃取）分别为94.2±2.9%和98±2.0%。分析响应在灵敏度下限0.05mg/L至至少10mg/L范围内呈线性。在0.5-4.0mg/L浓度范围内，批间变异系数（CV）为2.3%至2.9%。为说明稳健方法测试参数选择的原理，我们给出了这些过程的优化图。此外，我们还讨论了填充柱和膜吸附剂作为配套萃取装置的优点。
