Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran, Iran.
J Chromatogr A. 2012 Jun 22;1243:6-13. doi: 10.1016/j.chroma.2012.04.050. Epub 2012 Apr 26.
In the present work, for the first time a new set-up was presented for simultaneous extraction of acidic and basic drugs using a recent novel electrically-enhanced microextraction technique, termed electromembrane extraction at low voltages followed by high performance liquid chromatography with ultraviolet detection. Nalmefene (NAL) as a basic drug and diclofenac (DIC) as an acidic drug were extracted from 24 mL aqueous sample solutions at neutral pH into 10 μL of each acidified (HCl 50 mM) and basic (NaOH 50 mM) acceptor solution, respectively. Supported liquid membranes including 2-nitrophenyl octyl ether containing 5% di-(2-ethylhexyl) phosphate and 1-octanol were used to ensure efficient extraction of NAL and DIC, respectively. Low voltage of 40 V was applied over the SLMs during 14 min extraction time. The influences of fundamental parameters affecting the transport of target drugs were optimized using experimental design. Under optimal conditions, NAL and DIC were extracted with extraction recoveries of 12.5 and 14.6, respectively, which corresponded to preconcentration factors of 300 and 350, respectively. The proposed technique provided good linearity with correlation coefficient values higher than 0.9956 over a concentration range of 8-500 μg L⁻¹ and 12-500 μg L⁻¹ for NAL and DIC, respectively. Limits of detection and quantifications, and intra-day precisions (n=3) were less than 4 μg L⁻¹, 12 μg L⁻¹, and 10.1%, respectively. Extraction and determination of NAL and DIC in human urine samples were successfully performed. In light of the data obtained in the present work, this new set-up for EME with low voltages has a future potential as a simple, selective, and fast sample preparation technique for simultaneous extraction and determination of acidic and basic drugs in different complicated matrices.
在本工作中，首次提出了一种新的装置，用于使用最近开发的新型电增强微萃取技术，即低电压下的电膜萃取，随后进行高效液相色谱-紫外检测，同时萃取酸性和碱性药物。纳美芬（NAL）作为碱性药物，双氯芬酸（DIC）作为酸性药物，在中性 pH 下从 24 mL 水相样品溶液中分别萃取到 10 μL 酸化（HCl 50 mM）和碱性（NaOH 50 mM）接受溶液中。支撑液膜包括 2-硝基苯基辛基醚，其中含有 5%二（2-乙基己基）磷酸和 1-辛醇，分别用于确保 NAL 和 DIC 的有效萃取。在 14 分钟的萃取时间内，在 SLM 上施加 40 V 的低电压。使用实验设计优化了影响目标药物传输的基本参数的影响。在最佳条件下，NAL 和 DIC 的萃取回收率分别为 12.5%和 14.6%，相应的预浓缩因子分别为 300 和 350。该技术提供了良好的线性关系，相关系数值均高于 0.9956，对于 NAL 和 DIC，浓度范围分别为 8-500 μg L⁻¹和 12-500 μg L⁻¹。检测限和定量限以及日内精密度（n=3）均小于 4 μg L⁻¹、12 μg L⁻¹和 10.1%。成功地对人尿样中的 NAL 和 DIC 进行了提取和测定。根据本工作中获得的数据，这种用于低电压 EME 的新装置具有作为一种简单、选择性和快速的样品制备技术的未来潜力，用于同时从不同复杂基质中提取和测定酸性和碱性药物。
