机构地区: 广西科技大学生物与化学工程学院
出 处: 《理化检验(化学分册)》 2010年第6期680-683,691,共5页
摘 要: 制备了壳聚糖/多壁碳纳米管修饰石墨电极(记为CS-MCNT′s/GE),并采用循环伏安法研究了双氯芬酸钠在该修饰电极上的电化学行为。基于双氯芬酸钠在CS-MCNT′s/GE上的催化氧化和不可逆电对的双安培检测原理,通过偶合双氯芬酸钠的氧化和MnO4-在铂电极上的还原两个不可逆电极过程,提出了流动注射双安培法直接测定双氯芬酸钠浓度的方法。在pH 6.8的磷酸盐缓冲溶液中,外加电位差为0 V时,双氯芬酸钠的峰电流与其浓度在8.0×10-7~2.0×10-4mol.L-1范围内呈线性关系,检出限(3S/N)为2.0×10-7mol.L-1。连续测定1.0×10-5mol.L-1双氯芬酸钠标准溶液20次,相对标准偏差为4.75%,以双氯芬酸钠片为基底,加标回收率在98.0%~105.5%之间。 The chitosan-multi-walled carbon nanotubes composite film modified paraffin soaked graphite electrode(abbreviated CS-MCNT′s/GE) was prepared,and the electrochemical behavior of diclofenac sodium(DS) at this modified electrode was studied by cyclic voltammetry.Based on the catalytic oxidation of DS at CS-MCNT′s/GE,and on the principle of bi-amperometric detection of irreversible electrode reaction,a method of direct FI-biamperometric determination of DS was proposed.In the bi-amperometric detection system,when a potential of 0 V was applied,irreversible catalytic oxidation of DS was carried out at CS-MCNT′s/GE,and irreversible reduction of MnO-4 carried out at the other Pt-electrode in a phosphate buffer solution of pH 6.8.Linear relationship between the oxidation peak currents and concentrations of DS was obtained in the range of 8.0×10-7-2.0×10-4mol·L-1,with detection limit(3S/N) of 2.0×10-7mol·L-1.Test for precision was performed at 1.0×10-5mol·L-1 DS,the values of RSD(n=20) found was 4.75%.Using DS tablet sample as matrix,recovery test was made by standard addition method,the values of recovery were found in the range of 98.0%-105.5%.