液-液-液微萃取-高效液相色谱法测定人血浆中的局部麻醉剂

Determination of Local Anaesthetics in Human Plasma by Liquid-Liquid-Liquid Microextraction Coupled with High Performance Liquid Chromatography

建立了液-液-液微萃取与高效液相色谱联用技术同时测定人血浆中3种局部麻醉剂利多卡因、布比卡因和丁卡因的方法。考察了萃取时间、料液pH值和搅拌速度的影响，取佳萃取条件为萃取溶剂为200μL苯，接受相为1．0μL0．2mol／L HCl，搅拌速度为250r／min，萃取时问为45min。在该条件下，获得了高的富集因子（大于305倍）。方法的线性范围为：利多卡因和布比卡因0．025～5mg／L，丁卡因0．05～5mg／L，相关系数大于0．996；检出限依次为0．005、0．015和0．025mg／L；相对标准偏差小于5％。该方法能有效地去除血浆中复杂基体的干扰，萃取效率高，有机溶剂消耗少，是一种有效、灵敏的同时测定血浆中利多卡因、布比卡因和丁卡因的方法。

Liquid-liquid-liquid microextraction （LLLME） coupled with high performance liquid chromatography was developed for the simultaneous determination of three kinds of local anaesthetics, lidocaine, bupivacaine, and tetracaine in human plasma. The effects of stirring rate, extraction time, and pH in the donor phase on the enrichment factor of analytes were investigated. The optimal experimental conditions, 200 ILL benzene as organic phase, 1.0 μL 0.2 mol/L HCl as acceptor phase, 250 r/min of the stirring rate, and 45 min of the extraction time, were selected. Under these conditions, high enrichment factors （ more than 305 fold for all analytes） were obtained. The linear range of studied analytes were from 0. 025 to 5 mg/L except tetracaine which was from 0. 05 to 5 mg/L with correlation coefficients （r） better than 0. 996. The limits of detection was 0. 005 mg/L for lidocaine, 0. 015 mg/L for bupivacaine, and 0. 025 mg/L for tetracaine at signal-to-noise ratio of 3 （ S/N = 3 ）. The relative standard deviations were lower than 5 %. With LLLME, some interfering effects from the substances in plasma which interfered with the determination of analytes were eliminated efficiendy. The method with little solvent consumption was sensitive and suitable for the determination of lidocaine, bupivacaine and tetracaine in human plasma. This method was applied to the specimen of patient who was treated with anaesthesia of lidocaine and bupivacaine, and results showed the possibility for the simultaneous determination of above two local anaesthetics in human plasma.