Department of Analytical Chemistry, Faculty of Sciences, University of Córdoba, "Marie Curie Annex" Building, Campus of Rabanales, Córdoba, Spain.
Anal Chim Acta. 2011 Jun 10;695(1-2):11-7. doi: 10.1016/j.aca.2011.03.047. Epub 2011 Apr 1.
The capability of antioxidant compounds to reduce gold(III) to gold nanoparticles has been kinetically studied in the presence of cetyltrimethylammonium bromide using stopped-flow mixing technique and resonance light scattering as detection system. This study has given rise to a simple and rapid method for the determination of several synthetic and natural antioxidants used as additives in foodstuff samples. The formation of AuNPs was monitored by measuring the initial reaction-rate of the system in about 5s, using an integration time of 0.1s. Dynamic ranges of the calibration graphs and detection limits, obtained with standard solutions of the analytes, were (μmolL⁻¹): gallic acid (0.04-0.59, 0.01), propyl gallate (0.04-1.41, 0.01), octyl gallate (0.03-0.35, 0.08), dodecyl gallate (0.02-0.30, 0.007), butylated hydroxyanisol (0.07-0.39, 0.009), butylated hydroxytoluene (0.04-0.32, 0.01), ascorbic acid (0.11-1.72, 0.03) and sodium citrate (0.07-1.29, 0.02). The regression coefficients were higher than 0.994 in all instances. The precision of the method, expressed as RSD%, was established at two concentration levels of each analyte, with values ranging between 0.6 and 4.8%. The practical usefulness of the developed method was demonstrated by the determination of several antioxidant additives in foodstuff samples, which were extracted, appropriately diluted and assayed, obtaining recoveries between 95.4 and 99.5%. The results obtained were validated using two reference methods.
抗氧化化合物将三价金还原为金纳米粒子的能力已在十六烷基三甲基溴化铵存在下使用停流混合技术和共振光散射作为检测系统进行了动力学研究。这项研究为测定几种作为食品添加剂使用的合成和天然抗氧化剂提供了一种简单快速的方法。通过测量系统在大约 5s 内的初始反应速率，使用 0.1s 的积分时间，可以监测 AuNPs 的形成。使用分析物的标准溶液获得的校准曲线的动态范围和检测限（μmolL⁻¹）为：没食子酸（0.04-0.59，0.01）、没食子酸丙酯（0.04-1.41，0.01）、没食子酸辛酯（0.03-0.35，0.08）、没食子酸十二酯（0.02-0.30，0.007）、羟基茴香醚（0.07-0.39，0.009）、羟基甲苯（0.04-0.32，0.01）、抗坏血酸（0.11-1.72，0.03）和柠檬酸钠（0.07-1.29，0.02）。在所有情况下，回归系数均高于 0.994。该方法的精密度以每个分析物的两个浓度水平的 RSD%表示，其值在 0.6 到 4.8%之间。通过对食品样品中的几种抗氧化添加剂进行提取、适当稀释和测定，证明了所开发方法的实际有用性，回收率在 95.4%至 99.5%之间。使用两种参考方法验证了所得结果。
