期刊
JOURNAL OF CHROMATOGRAPHY B
卷 739, 期 1, 页码 175-182出版社
ELSEVIER SCIENCE BV
DOI: 10.1016/S0378-4347(99)00344-8
关键词
solid-phase microextraction; protein binding; lidocaine
Direct-immersion solid-phase microextraction (SPME) has been used to extract the local anesthetic lidocaine from human plasma. A simplified model shows the relationship between the total amount of drug in plasma and the amount of drug extracted. The model takes into account that the drug participates between the fiber, sample and proteins. Therefore the model can also be used to obtain a good approximation of the drug-protein binding. Extraction yields of lidocaine in plasma are <1%, and the protein binding of lidocaine was found to be about 74% at pH 9.5. A SPME method has been developed for the determination of the total amount of lidocaine in plasma. The protein binding was reduced by acidification and, subsequently, the sample was deproteinized with trichloroacetic acid. With a 100-mu m polydimethylsiloxane-coated fiber and addition of sodium chloride to the sample an extraction yield of about 12% at equilibrium (45 min) has been obtained. The relative standard deviation of this method is <10%. A linear range was found from 25 to 2000 ng ml(-1) lidocaine in plasma (r=0.998) with a detection limit of 5 ng ml(-1) in plasma. An extraction yield of about 80% could be obtained after an overnight extraction by use of a 65-mu m polydimethylsiloxane-divinylbenzene-coated fiber. if an extraction time of 10 min is used with this fiber, the same yield is obtained as with the single-phase fiber in 45 min. However, the drawback of this mixed-phase fiber is its much shorter lifetime. (C) 2000 Elsevier Science B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据