Departamento de Química Analítica, Universidad de Extremadura, Spain.
Analyst. 2012 Nov 7;137(21):5153-60. doi: 10.1039/c2an35844a. Epub 2012 Sep 24.
The relevance of the development of microchip electrophoresis applications in the field of food analysis is considered in this work. A novel method to determine important phenolic compounds in extra virgin olive oil samples using a miniaturized chemical analysis system is presented in this paper. Three interesting phenolic compounds in olive oil and fruit (tyrosol, hydroxytyrosol and oleuropein glucoside) were studied by end-channel amperometric detection using a 100 μm gold wire as working electrode in glass microchip electrophoresis. The electrochemical behavior of these compounds was studied and the medium to carry out their detection was selected (0.1 M aqueous sulfuric acid). The best conditions for the separation were achieved in sodium tetraborate (10% methanol, pH 9.50) with different concentrations for the sample and the running buffer in order to allow the sample stacking phenomenon. The injection was carried out using 600 V for 3 s and the separation voltage was set at 1000 V. The quality of the method was evaluated through its analytical figures of merit and by its performance on real extra virgin olive oil samples. Determination of these compounds was carried out using the standard addition calibration method with good recoveries.
本工作考虑了微芯片电泳应用在食品分析领域的发展相关性。本文提出了一种使用微型化学分析系统测定特级初榨橄榄油样品中重要酚类化合物的新方法。使用 100μm 金丝作为工作电极，在玻璃微芯片电泳中进行末端通道安培检测，研究了橄榄油和水果中的三种有趣的酚类化合物（酪醇、羟基酪醇和橄榄苦苷）。研究了这些化合物的电化学行为，并选择了检测它们的介质（0.1 M 硫酸水溶液）。通过在不同浓度的样品和运行缓冲液中加入硼酸钠（10%甲醇，pH9.50），实现了最佳的分离条件，以允许样品堆积现象。通过 600V 进行 3s 的进样，分离电压设置为 1000V。通过分析的质量指标和对真实特级初榨橄榄油样品的性能来评估该方法的质量。通过标准添加校准方法进行这些化合物的测定，回收率良好。
