Laboratory of Analytical Chemistry, Department of Chemistry, University of Athens, Athens, Greece.
Talanta. 2011 Sep 15;85(3):1412-8. doi: 10.1016/j.talanta.2011.06.037. Epub 2011 Jun 17.
This work reports a sequential-injection analysis (SIA) method with chemiluminescence (CL) detection for the rapid assay of the total antioxidant capacity (TAC) in wines. The method exploited the Co(II)-catalysed CL reaction of luminol with hydrogen peroxide in alkaline medium. Zones of sample, hydrogen peroxide, catalyst (Co(II) solution) and alkaline luminol were sequentially aspirated into the holding coil of the SIA manifold. Then, the flow was reversed and the stacked zones were directed to the CL detector. As the zones overlapped, antioxidants in the samples scavenged a portion of hydrogen peroxide and the decrease in the CL intensity was monitored and related to the TAC. The chemical and geometric conditions were studied and the method was validated in terms of linearity, accuracy (trueness and precision), matrix effects, signal additivity and robustness. The reproducibility of the method (expressed as the between-days % relative standard deviation) was between 2.5 and 3.4% and the trueness (expressed as the % recovery in wines spiked with gallic acid) was in the range 96.7-97.3%. The sampling frequency was 60 samples h(-1). The proposed SIA-CL method was compared with the DPPH method and the Folin-Ciocalteau (FC) method for the analysis of 25 wine samples.
本工作报道了一种顺序注射分析（SIA）与化学发光（CL）检测联用的方法，用于快速测定葡萄酒中的总抗氧化能力（TAC）。该方法利用 Co(II)催化鲁米诺与过氧化氢在碱性介质中的 CL 反应。样品、过氧化氢、催化剂（Co(II)溶液）和碱性鲁米诺区域依次被吸入到 SIA 流路的保持线圈中。然后，流路被反转，堆叠的区域被导向 CL 检测器。当区域重叠时，样品中的抗氧化剂会清除一部分过氧化氢，监测 CL 强度的下降，并将其与 TAC 相关联。研究了化学和几何条件，并从线性、准确性（准确度和精密度）、基质效应、信号加和性和稳健性等方面对该方法进行了验证。该方法的重现性（表示为日间%相对标准偏差）在 2.5%至 3.4%之间，准确度（表示为用没食子酸加标葡萄酒中的%回收率）在 96.7%至 97.3%范围内。采样频率为 60 个样品 h(-1)。将所提出的 SIA-CL 方法与 DPPH 法和 Folin-Ciocalteau（FC）法进行了比较，用于分析 25 个葡萄酒样品。
