维多利亚艳蓝BO分光光度法测定羟基自由基

建立了一种测定羟基自由基的新方法,并将其应用于筛选和评价抗氧化物质的抗氧化活性。以乳化剂OP为稳定剂,在pH(2±0.1)的磷酸-磷酸二氢钠缓冲溶液中,Fenton反应产生的羟基自由基被过量的KI捕获,生成的I3-与维多利亚艳蓝BO(VPBBO)反应生成艳蓝色的离子缔合物,分光光度法测定羟基自由基。缔合物的最大吸收波长571nm,表观摩尔吸光系数(以双氧水浓度计)6.3×104L/(mol.cm),线性范围0.0～0.40mg/L。本方法成功地应用于抗坏血酸等3种抗氧化剂以及弥猴桃等5种水果提取液的抗氧化活性的测定。

Determination of Hydroxyl Radical by Victoria Pure Blue BO Spectrophotometry

A new method for the determination of scavenging rate of hydroxyl radical with antioxidant was developed and applied in selecting and evaluating the anti-hydroxyl radical activity of antioxidant.The hydroxyl radical from the Fenton reaction was captured by excess potassium iodide,the iodine and victoria pure blue BO(VPB BO) reacted to form a pure blue color complex.The absorbency was measured at 571 nm.The equation of linear regression was A = 1.76C(mg/L) + 0.002,with the correlation coefficient 0.999 4.The Beer's law was obeyed in the range of 0.0～0.40mg/L.The apparent molar absorptivity(calculated by the concentration of hydrogen peroxide) was 6.3×104 L/(mol·cm).The activity of three antioxidant and five kinds of fruit extract were measured with satisfactory results.