Lin S N, Moody D E, Bigelow G E, Foltz R L
Center for Human Toxicology, Department of Pharmacology and Toxicology, University of Utah, Salt Lake City 84112, USA.
J Anal Toxicol. 2001 Oct;25(7):497-503. doi: 10.1093/jat/25.7.497.
In order to support studies on various medication protocols for the treatment of cocaine abuse, an accurate, precise, and sensitive (2.5 to 750 ng/mL) liquid chromatography-tandem mass spectrometry assay was developed to determine cocaine and benzoylecgonine in human plasma. Cocaine-d3 and benzoylecgonine-d3 were added as internal standards and samples were subjected to solid-phase extraction. Cocaine recovery was 94.4% and benzoylecgonine was 80.3% at 2.5 ng/mL. The selected reaction monitoring of parent ions at m/z 304 and 290 resulted in strong fragments at m/z 182 and 168 for cocaine and benzoylecgonine, respectively. The method was fully validated. The mean measured concentration at the 2.5 ng/mL, the lower limit of quantitation, was within 10.8% of the target and the precision determined at the low (5 ng/mL), medium (50 ng/mL), and high (650 ng/mL) quality controls ranged from 0.9 to 6.2 %CV. Cocaine and benzoylecgonine concentrations in plasma treated with 1% NaF showed changes of less than 10% when maintained at room temperature for up to 7 h and no significant changes when subjected to three freeze-thaw cycles. The concentrations of cocaine and benzoylecgonine remained stable in plasma samples stored at -20 degrees C for up to 11 months. Methanolic stock solutions of both analytes are stable, staying within 2% of the freshly prepared stock solutions, when stored at -20 degrees C for up to 235 days. Both extracted analytes reconstituted in methanolic solutions are stable for up to seven days whether stored at -20 degrees C or at room temperature on the autosampler. The method is rugged, rapid, and robust and has been applied to the batch analysis of more than 700 samples during pharmacokinetic profiling to assess potential interactions between intravenous (i.v.) cocaine challenge and treament medications. Results from three of these subjects receiving 40 mg (i.v.) cocaine demonstrate the utility of the method.
为了支持关于治疗可卡因滥用的各种药物方案的研究，开发了一种准确、精密且灵敏（2.5至750 ng/mL）的液相色谱 - 串联质谱分析法，用于测定人血浆中的可卡因和苯甲酰爱康宁。添加可卡因 - d3和苯甲酰爱康宁 - d3作为内标，样品进行固相萃取。在2.5 ng/mL时，可卡因回收率为94.4%，苯甲酰爱康宁为80.3%。对质荷比为304和290的母离子进行选择反应监测，分别得到可卡因和苯甲酰爱康宁在质荷比为182和168处的强碎片。该方法经过了全面验证。在2.5 ng/mL（定量下限）时的平均测量浓度在目标值的10.8%以内，在低（5 ng/mL）、中（50 ng/mL）和高（650 ng/mL）质量控制下测定的精密度范围为0.9%至6.2%CV。用1%氟化钠处理的血浆中，可卡因和苯甲酰爱康宁浓度在室温下保存长达7小时时变化小于10%，经过三个冻融循环时无显著变化。在 - 20℃下储存长达11个月的血浆样品中，可卡因和苯甲酰爱康宁浓度保持稳定。两种分析物的甲醇储备溶液在 - 20℃下储存长达235天时稳定，保持在新制备储备溶液的2%以内。无论是在 - 20℃还是在自动进样器上室温储存，两种在甲醇溶液中重构的萃取分析物在长达七天内都稳定。该方法耐用、快速且稳健，已应用于药代动力学分析期间对700多个样品的批量分析，以评估静脉注射（i.v.）可卡因激发与治疗药物之间的潜在相互作用。其中三名接受静脉注射40 mg可卡因的受试者的结果证明了该方法的实用性。
