摘要
用亲水性离子液体氯化1-戊基-3-甲基咪唑([AMIM]Cl)作修饰剂构置了离子液体修饰碳糊电极(IL/CPE)。在pH=3.53Britton-Robinson(B.R)缓冲溶液中,用循环伏安法(CV)和方波伏安法(SWV)研究了黄芩苷在IL/CPE和裸碳糊电极(CPE)上的电化学行为,建立了测定尿样和血清样品中黄芩苷含量的新方法。在CPE上黄芩苷氧化、还原峰之间峰电位差(△Ep)为0.204V,在IL/CPE上其峰峰电位差减小为0.103V;黄芩苷在IL/CPE上的电流响应是其在CPE上的7.1倍。表明IL/CPE对黄芩苷的氧化还原反应有很好的电催化作用。计算了黄芩苷在此修饰电极上的电子转移系数和电子转移速率常数。在方波伏安曲线上,黄芩苷的氧化电流与其浓度在1.0×10^-8~2.0×10^-6mol/L范围内呈线性关系。检出限为3.0×10^-9mol/L(S/N=3)。连续6次测定浓度为4.0×10^-7mol/L黄芩苷溶液的RSD为1.3%。
An ionic liquid modified carbon paste electrode (IL/CPE) was fabricated with hydrophilic ionic liquid 1-amyl-3-methylimidazolium chloride ([ AMIM ] Cl ) as a modifier, The electrochemical behavior of baicalin at the modified electrode and bare carbon paste electrode (CPE) was investigated in a Britton- Robinson ( B-R ) buffer solution ( pH = 3.53 ) by cyclic voltamme.try ( CV ) and square wave voltammetry (SWV), and a novel method 'for the determination of baicalin in urine and serum samples was thus established. At CPE, the peak-to-peak potential separation( △Ep ) of baicalin was 0. 204V, while at IL/CPE, the △Ep decreased to 0. 103 V. Furthermore, the current response of baicalin at IL/CPE was 7.1 times of that at CPE. These indicated the IL/CPE possessed an excellent electrocatalytic activity for the redox of baicalin. The electron transfer coefficient and standard rate constant of baicalin at IL/CPE were calculated. In the SWV curves, a linear dependence of oxidation current on baicalin concentration was obtained in the range of 1.0 × 10^-8 -2. 0 × 10^-6 mol/L(r =0. 999 8), with a detection limit of 3.0 × 10^-9 mol/L(S/N =3 ). The relative standard deviation of 4. 0 × 10^-7 mol/L baicalin was 1.3% for 6 consective measurements.
出处
《应用化学》
CAS
CSCD
北大核心
2008年第8期899-903,共5页
Chinese Journal of Applied Chemistry
基金
国家自然科学基金(20675062)资助项目
关键词
伏安法
电催化
离子液体
碳糊电极
黄芩苷
voltammetry, electrocatalysis, ionic liquid, carbon paste electrode, baicalin