阻抑-催化褪色光度法测定痕量绿原酸

Determination of Trace Isochlorogenic Acid by Inhibition-Catalysis Discoloring Spectrophotometry

在盐酸介质中 ,绿原酸能灵敏地阻抑铁 催化过氧化氢还原亮绿SF的褪色指示反应 ,据此建立了测定痕量绿原酸的阻抑 催化动力学光度分析方法。该方法测定绿原酸的线性范围为 0～ 0 .12mg/L ;检出限为4 .2× 10 -6g/L。对浓度为 0 .0 8mg/L绿原酸标准溶液 6次平行测定的相对标准偏差为 3.8% ;回收率为 93.4 %～ 10 5 %。考察了反应的最佳条件和动力学参数 ,探讨了反应机理。该方法应用于金银花浸取液中绿原酸含量的测定 。

It has been observed that isochlorogenic acid can sensitively inhibit the light green SF descolorization reaction with H 2O 2 catalyzed by Fe? in hydrochloric acid medium. Based on this reaction an inhibition kinetic spectropho tometric method for the determination of trace isochlorogenic acid was established. It is shown that the linear range and detection limit are 0～0.12 mg/L and 4.2×10 -6 g/L respectively for isochlorogenic acid. The relative standard deviation of 0.08 mg/L isochlorogenic acid for 6 parallel determination is 3.8%, The recovery is in the range of 93.4%～105%. The optimum condition, kinetic parameters and reaction mechanism were investigated. This method has been used to determine isochlorogenic acid in leaching liquor of honeysucle with satisfactory results.