Hansen Frederik André, Pedersen-Bjergaard Stig
Department of Pharmacy, University of Oslo, P.O. Box 1068 Blindern, 0316 Oslo, Norway.
Department of Pharmacy, University of Oslo, P.O. Box 1068 Blindern, 0316 Oslo, Norway; Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark.
J Chromatogr A. 2021 Feb 22;1639:461915. doi: 10.1016/j.chroma.2021.461915. Epub 2021 Jan 21.
In this fundamental study, streptomycin was extracted successfully from urine and plasma using electromembrane extraction (EME). Streptomycin is an aminoglycoside with log P -7.6 and was selected as an extremely polar model analyte. EME is a microextraction technique, where charged analytes are extracted under the influence of an electrical field, from sample, through a supported liquid membrane (SLM), and into an acceptor solution. The SLM comprised 2-nitrophenyl pentyl ether (NPPE) mixed with bis(2-ethylhexyl) phosphate (DEHP). DEHP served as ionic carrier and facilitated transfer of streptomycin across the SLM. For EME from urine and protein precipitated plasma, the optimal DEHP content in the SLM was 45-50% w/w. From untreated plasma, the content of DEHP was increased to 75% w/w in order to suppress interference from plasma proteins. Most endogenous substances with UV absorbance were not extracted into the acceptor. Proteins and phospholipids were also discriminated, with <0.6% of proteins and <0.02% of phospholipids found in the acceptor after EME. Thus, despite the fact that the SLM was permeable to more polar molecules, the EME still provided very efficient sample cleanup. Extraction process efficiencies of 98% and 61% were achieved from urine and plasma, respectively, with linear calibration (R > 0.9929), absence of significant matrix effects (94-112%), accuracy of 94-125%, and RSD ≤ 15% except at LLOQ. The average current during extractions was 67 µA or less. The findings of this paper demonstrated that EME is feasible for extraction of basic analytes of extreme polarity.
在这项基础研究中，使用电膜萃取（EME）成功地从尿液和血浆中萃取出链霉素。链霉素是一种log P为 -7.6的氨基糖苷类药物，被选为极具极性的模型分析物。EME是一种微萃取技术，在该技术中，带电分析物在电场影响下从样品中通过支撑液膜（SLM）萃取到接受液中。SLM由2-硝基苯基戊基醚（NPPE）与磷酸二（2-乙基己基）酯（DEHP）混合而成。DEHP作为离子载体，促进链霉素穿过SLM。对于从尿液和经蛋白沉淀的血浆中进行EME，SLM中DEHP的最佳含量为45 - 50%（w/w）。从未经处理的血浆中进行萃取时，DEHP的含量增加到75%（w/w），以抑制血浆蛋白的干扰。大多数具有紫外吸收的内源性物质未被萃取到接受液中。蛋白质和磷脂也被区分开来，EME后接受液中发现的蛋白质含量<0.6%，磷脂含量<0.02%。因此，尽管SLM对极性更强的分子具有渗透性，但EME仍能提供非常有效的样品净化。从尿液和血浆中萃取过程的效率分别达到98%和61%，具有线性校准（R > 0.9929），无显著基质效应（94 - 112%），准确度为94 - 125%，除定量下限外相对标准偏差≤15%。萃取过程中的平均电流为67 μA或更低。本文的研究结果表明，EME对于萃取极具极性的碱性分析物是可行的。
