光度滴定法测定丁香酸和对香豆酸的解离常数  

Determination of the Dissociation Constants of Syringic Acid and p-Coumaric Acid by Spectral Methodology

作　　者：桂玉娟 付洁 任佳 刘娜 夏雁青[1] 石铁生 Gui Yujuan;Fu Jie;Ren Jia;Liu Na;Xia Yanqing;Shi Tiesheng(College of Chemistry,Chemical Engineering and Materials Science,Zaozhuang University,Zaozhuang 277160,China)

机构地区：[1]枣庄学院化学化工与材料科学学院,山东枣庄277160

出　　处：《山东化工》2023年第20期161-164,共4页Shandong Chemical Industry

摘　　要：丁香酸和对香豆酸都是存在于植物中的天然抗氧化剂,具有抗菌、消炎和抗癌等药理作用。在水溶液中它们都存在解离平衡,在25.0℃和1.0 mol/L离子强度下我们用光度滴定法获得了它们的解离平衡常数pK_(a1)和pK_(a2)。在获得这些解离常数后就可以很容易地分析丁香酸和对香豆酸的三种质子化形态随pH值的分布情况,这将对研究它们的抗氧化反应机理具有重要的意义。Syringic acid(SA)and p-coumaric acid(p-CA)are natural antioxidants found in plants,which have good antibacterial and anti-inflammatory properties.Two dissociation equilibria are involved in aqueous solution for both of them.The UV-vis spectra as a function of pH have been studied and acid dissociation constants pK_(a1) and pK_(a2) have been determined by a spectrophotometric titration method at 25.0℃ and 1.0 mol/L ionic strength.With the acquired pK_(a1) and pK_(a2) values,the distributions of the protolytic species can be derived readily,conferring a solid base for studying their anti-oxidative mechanisms.

关 键 词：丁香酸 对香豆酸 光度滴定法 解离常数 

分 类 号：O657.3[理学—分析化学]