de Araújo Tatiane Alfonso, Cardoso Juliano Carvalho, Barbosa Antonio Marcos Jacques, Ferreira Valdir Souza
Departamento de Química, CCET, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS 79070-900, Brazil.
Colloids Surf B Biointerfaces. 2009 Oct 15;73(2):408-14. doi: 10.1016/j.colsurfb.2009.06.019. Epub 2009 Jun 23.
In this study, two quantitative differential-pulse polarography (DPP) and square-wave voltammetry (SWV) methods were developed to determine total chlorogenic acid (CGA). Studies on this compound involve its reduction at a hanging mercury drop electrode in micellar media-a simple, fast, reliable, and sensitive method. The use of surfactant cationic cetyltrimethylammonium bromide (CTAB) was pivotal to the development of these methods, allowing for satisfactory changes in CGA reduction. The supporting electrolyte which provided the best-defined CGA determination was 0.04-mol L(-1) phosphate buffer at pH 6.0 in the presence of CTAB. Based on this use and under optimized conditions, the two new DPP and SWV methods for CGA analysis had detection limits of 2.36 x 10(-7) and 1.34 x 10(-9)mol L(-1), respectively, for a pure standard. Analysis of the standard in the presence of treated instant coffee and mate tea samples allowed for good average recovery rates, ranging from 97.06% to 105.90%.
在本研究中，开发了两种定量差分脉冲极谱法（DPP）和方波伏安法（SWV）来测定总绿原酸（CGA）。对该化合物的研究涉及在胶束介质中的悬汞滴电极上对其进行还原——这是一种简单、快速、可靠且灵敏的方法。表面活性剂阳离子十六烷基三甲基溴化铵（CTAB）的使用对这些方法的开发至关重要，它能使CGA还原产生令人满意的变化。在CTAB存在下，能提供最明确的CGA测定结果的支持电解质是pH 6.0的0.04 mol L⁻¹磷酸盐缓冲液。基于此应用并在优化条件下，用于CGA分析的两种新DPP和SWV方法对纯标准品的检测限分别为2.36×10⁻⁷和1.34×10⁻⁹mol L⁻¹。在经过处理的速溶咖啡和马黛茶样品存在的情况下对标准品进行分析，平均回收率良好，范围为97.06%至105.90%。
