Yamini Yadollah, Reimann Curt T, Vatanara Alireza, Jönsson Jan Ake
Department of Chemistry, Tarbiat Modarres University, P.O. Box 11415-175, Tehran, Iran.
J Chromatogr A. 2006 Aug 18;1124(1-2):57-67. doi: 10.1016/j.chroma.2006.05.001. Epub 2006 May 22.
This paper presents a new three-phase liquid-phase microextraction (LPME) strategy for extraction and preconcentration of salbutamol (SB) and terbutaline (TB) from aqueous samples, including urine. The drugs were extracted from 11 ml of aqueous sample (source phase; SP) into an organic phase with microliter volume located inside the pores of a polypropylene hollow fiber, and then back-extracted into 24 microl of a second aqueous solution as the receiving phase (RP), located in the lumen of the hollow fiber. In preliminary experiments, we tried to transport the drugs using a pH gradient between the two sides of the hollow fiber. Due to the existence of both amine and phenolic groups on the drugs, very little transport occurred and enrichment factors (EF) less than one were obtained. Further experiments were done in the presence of bis(2-ethylhexyl) monohydrogenphosphoric acid (D2EHPA) or methyltrioctylammonium chloride (Aliquat 336) in the organic phase, to extract drugs from acidic and basic matrices, respectively. Results showed that transport of drugs from alkaline solution into 1M of sodium bromide occurred when the membrane was impregnated with dihexyl ether containing 20% Aliquat 336. To optimize the EF, the effects of different parameters such as the nature of organic solvent used to impregnate the membrane, compositions and volumes of SP and RP, type and concentration of carrier, extraction time and stirring rate were investigated. Optimal results were obtained in the presence of 0.005 M of NaOH (pH 11.70) in the SP, 1M of NaBr in the RP, 20% of Aliquat 336 in dihexyl ether as membrane impregnation solvent, stirring rate of 500 rpm and extraction time of 60 min. Under these conditions, enrichment factors of 52.9 and 213.1, dynamic linear ranges of 20-5000 and 10-5000, and limits of detection of 2.5 and 0.5 ng/ml were obtained for salbutamol and terbutaline, respectively. Also determination of drugs in environmental water and urine samples in the range of nanograms per millilitre with RSDs<10% was possible using HPLC-photodiode array detection or HPLC-MS.
本文提出了一种新的三相液相微萃取（LPME）策略，用于从包括尿液在内的水性样品中萃取和预富集沙丁胺醇（SB）和特布他林（TB）。药物从11毫升水性样品（源相；SP）中被萃取到位于聚丙烯中空纤维孔内的微升级有机相中，然后再反萃取到位于中空纤维内腔的24微升第二种水溶液作为接收相（RP）中。在初步实验中，我们试图利用中空纤维两侧的pH梯度来转运药物。由于药物上同时存在胺基和酚基，转运量极少，获得的富集因子（EF）小于1。进一步的实验是在有机相中加入二（2-乙基己基）磷酸（D2EHPA）或甲基三辛基氯化铵（Aliquat 336）的情况下进行的，分别从酸性和碱性基质中萃取药物。结果表明，当膜用含有20% Aliquat 336的二己醚浸渍时，药物能从碱性溶液转运到1M溴化钠溶液中。为了优化富集因子，研究了不同参数的影响，如用于浸渍膜的有机溶剂的性质、源相和接收相的组成及体积、载体的类型和浓度、萃取时间和搅拌速率。在源相中存在0.005M NaOH（pH 11.70）、接收相中存在1M NaBr、二己醚中20% Aliquat 336作为膜浸渍溶剂、搅拌速率为500 rpm和萃取时间为60分钟的条件下获得了最佳结果。在此条件下，沙丁胺醇和特布他林的富集因子分别为52.9和213.1，动态线性范围分别为20 - 5000和10 - 5000，检测限分别为2.5和0.5 ng/ml。使用高效液相色谱 - 光电二极管阵列检测或高效液相色谱 - 质谱联用，还能够测定环境水样和尿液样品中纳克每毫升范围内的药物，相对标准偏差（RSDs）<10%。
