Tahmasebi Elham, Yamini Yadollah, Saleh Abolfazl
Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran, Iran.
J Chromatogr B Analyt Technol Biomed Life Sci. 2009 Jul 1;877(20-21):1923-9. doi: 10.1016/j.jchromb.2009.05.033. Epub 2009 May 21.
The applicability of hollow fiber liquid phase microextraction (HF-LPME) for extraction and preconcentration of trace amounts of pioglitazone (PGL) as an anti-diabetic drug in biological fluids, prior to determination by high-performance liquid chromatography (HPLC), was evaluated. In this technique, the target drug was extracted into di-n-hexyl ether immobilized in the wall pores of a porous hollow fiber from 10 mL of the aqueous sample (source phase, SP) with pH 8.0, and then back extracted into the receiving phase (RP) with pH 2.2 located in the lumen of the hollow fiber. The extraction occurred due to a pH gradient between the two sides of the hollow fiber. After extracting for a prescribed time, 24 microL of the RP solution was taken back into the syringe and injected directly into a HPLC instrument for quantification. The Taguchi orthogonal array (OAD) experimental design with an OA(16) (4(5)) matrix was employed to optimize the HF-LPME conditions. Different factors affecting the HF-LPME efficiency such as the nature of organic solvent used to impregnate the membrane, pH of the SP and RP, stirring speed, extraction time and ionic strength were studied and optimized. Under the optimum conditions (di-n-hexyl ether as membrane impregnation solvent, pHs of the SP and RP equal to 8.0 and 2.2, respectively, extraction time of 30 min, stirring speed of 500 rpm and 10% (w/v) NaCl for adjusting the ionic strength), preconcentration factor of 180, linear dynamic range (LDR) of 2.5-250 microg L(-1) with good correlation of determination (r(2)>0.998) and limit of detection (LOD) of 1.0 microg L(-1) were obtained for the target drug. The percent relative intra-day and inter-day standard deviations (RSDs%) based on five replicate determinations were 4.7 and 15%, respectively. Once LPME was optimized, the performance of the proposed technique was evaluated for the determination of PGL in different types of biological fluids such as plasma and urine samples. The results showed that the proposed HF-LPME method could be successfully applied to determine trace amounts of PGL in biological samples.
评估了中空纤维液相微萃取（HF-LPME）技术在高效液相色谱（HPLC）测定之前，用于萃取和预富集生物流体中痕量抗糖尿病药物吡格列酮（PGL）的适用性。在该技术中，目标药物从10 mL pH为8.0的水样（源相，SP）中萃取到固定在多孔中空纤维壁孔中的二正己醚中，然后反萃取到位于中空纤维内腔、pH为2.2的接收相（RP）中。萃取是由于中空纤维两侧的pH梯度而发生的。在规定时间萃取后，将24 μL的RP溶液吸回注射器并直接注入HPLC仪器进行定量。采用具有OA(16) (4(5))矩阵的田口正交阵列（OAD）实验设计来优化HF-LPME条件。研究并优化了影响HF-LPME效率的不同因素，如用于浸渍膜的有机溶剂的性质、SP和RP的pH、搅拌速度、萃取时间和离子强度。在最佳条件下（二正己醚作为膜浸渍溶剂，SP和RP的pH分别等于8.0和2.2，萃取时间30 min，搅拌速度500 rpm，10%（w/v）NaCl用于调节离子强度），目标药物的预富集因子为180，线性动态范围（LDR）为2.5 - 250 μg L(-1)，测定相关性良好（r(2)>0.998），检测限（LOD）为1.0 μg L(-1)。基于五次重复测定的日内和日间相对标准偏差（RSDs%）分别为4.7%和15%。一旦LPME得到优化，就评估了所提出的技术在测定不同类型生物流体（如血浆和尿液样品）中PGL的性能。结果表明，所提出的HF-LPME方法可成功应用于测定生物样品中痕量的PGL。
