Department of Analytical Chemistry and Organic Chemistry, Faculty of Chemistry, Rovira i Virgili University, Tarragona, Spain.
Electrophoresis. 2011 Aug;32(16):2114-22. doi: 10.1002/elps.201100054. Epub 2011 Jul 18.
In this study, the suitability of solid-phase extraction (SPE) coupled in-line to CE with UV-Vis detection was evaluated for the preconcentration and separation of diluted solutions of five pharmaceuticals compounds: benzafibrate, piroxicam, diclofenac sodium, naproxen and clofibric acid. An SPE analyte concentrator containing Oasis(®) HLB sorbent was constructed without frits and placed near the inlet end of the separation capillary. Different parameters such as sample pH, composition and volume of the elution plug and sample loading time were studied in order to obtain the maximum preconcentration factors. The LODs reached for standard samples were in the range 0.06-0.5 ng/mL with good reproducibility, and the developed strategy provides sensitivity enhancement factors around 14,000-fold in peak area and 5900-fold in peak height compared with the normal hydrodynamic injection. Finally, river water samples fortified with the pharmaceutical compounds were analyzed by the developed in-line SPE-CE-UV method in order to show the potential of the methodology for the analysis of environmental aquatic samples. For these samples, high values of relative recoveries, between 73-107% and 79-103% for two concentration levels, 5 and 25 ng/mL, respectively, were obtained and LODs ranged between 0.19 and 1 ng/mL.
在这项研究中，评估了固相萃取 (SPE) 与 CE 在线联用结合 UV-Vis 检测，用于预浓缩和分离五种药物化合物的稀释溶液：苯扎贝特、吡罗昔康、双氯芬酸钠、萘普生和氯贝酸。构建了一个不含玻璃料的 SPE 分析物浓缩器，其中含有 Oasis(®)HLB 吸附剂，并将其放置在分离毛细管的入口端附近。研究了不同的参数，如样品 pH 值、洗脱塞的组成和体积以及样品加载时间，以获得最大的预浓缩因子。标准样品的检出限在 0.06-0.5 ng/mL 范围内，具有良好的重现性，与正常的水力注射相比，开发的策略在峰面积和峰高方面提供了约 14000 倍和 5900 倍的灵敏度增强因子。最后，用开发的在线 SPE-CE-UV 方法分析了加标河水样品，以展示该方法在环境水样分析中的潜力。对于这些样品，在两个浓度水平 5 和 25 ng/mL 下，相对回收率分别在 73-107%和 79-103%之间，并且检出限在 0.19 和 1 ng/mL 之间。
