Department of Pharmaceutical Chemistry, School of Pharmacy, University of Oslo, P.O. Box 1068 Blindern, 0316 Oslo, Norway.
J Pharm Biomed Anal. 2012 Jan 5;57:33-8. doi: 10.1016/j.jpba.2011.08.026. Epub 2011 Aug 22.
Citalopram, loperamide, methadone, paroxetine, pethidine, and sertraline were extracted exhaustively with electromembrane extraction (EME) by increasing the number of hollow fibers from one to three. Experiments reported recoveries in the range 97-115% from 1000μl spiked water samples. EME was accomplished with 200V as extraction voltage, the extraction time was set to 10min (equilibrium), and the extraction unit was subjected to 1200 revolutions per minute (rpm). The same experiment with different geometry in a stagnant system conducted with 21μl acceptor solution provided recoveries from 50μl undiluted human plasma (pH 7.4) in the range of 56-102% for the six basic model substances. In each experiment the acceptor solution was distributed into three separately hollow fibers in the same sample vial. The importance of an electrical field was verified by comparing EME with liquid-phase microextraction (LPME) under optimal conditions and demonstrated that the time needed to reach equilibrium was reduced by EME. EME-LC/MS provided linearity >0.99 (r(2) values) for the six basic model substances, and the repeatability within the low therapeutic range (10ng/ml) was in the range 5.1-21.4% RSD. LC-MS provided estimated limit of quantification (S/N=10) in the range 0.6-3.2ng/ml. Eventually, patient samples from a reference laboratory were analyzed and provided reliable results with a relative difference <14% compared to stated values from the reference laboratory.
西酞普兰、洛哌丁胺、美沙酮、帕罗西汀、哌替啶和舍曲林经电膜萃取（EME）充分提取，通过将中空纤维数量从一个增加到三个。实验报告回收率范围为 1000μl 加标水样的 97-115%。EME 采用 200V 的萃取电压，萃取时间设定为 10min（平衡），萃取单元每分钟旋转 1200 转。在停滞系统中使用不同几何形状进行的相同实验，采用 21μl 接受溶液，从 50μl 未稀释的人血浆（pH 7.4）中获得 6 种基本模型物质的回收率在 56-102%范围内。在每个实验中，将接受溶液分配到同一样品小瓶中的三个单独的中空纤维中。通过将 EME 与最佳条件下的液相微萃取（LPME）进行比较，验证了电场的重要性，并证明 EME 缩短了达到平衡所需的时间。EME-LC/MS 为 6 种基本模型物质提供了>0.99（r(2) 值）的线性关系，在低治疗范围内（10ng/ml）的重复性在 5.1-21.4%RSD 范围内。LC-MS 提供了估计的定量限（S/N=10），范围为 0.6-3.2ng/ml。最终，参考实验室的患者样本进行了分析，并提供了可靠的结果，与参考实验室报告的值相比，相对差异<14%。
