聚对氨基苯磺酸修饰电极差分脉冲伏安法测定对乙酰氨基酚

Differential Pulse Voltammetric Determination of Acetaminophen with Poly-p-Aminobenzene Sulfonic Acid Modified Electrode

在由pH 7.0的磷酸盐缓冲溶液和2.0×10^(-3)mol·L^(-1)对氨基苯磺酸组成的支持电解质中,以100mV·s^(-1)扫描速率在玻碳电极上先后在电位-1.5～2.5V范围内循环扫描10周、在电位-1.5～1.5V范围内循环扫描15min,制得聚对氨基苯磺酸修饰的玻碳电极。循环伏安法研究发现:对乙酰氨基酚在该修饰电极上出现了一对氧化还原峰,两峰的电位差为30mV;差分脉冲伏安法研究发现:在pH5.9的磷酸盐缓冲溶液中,对乙酰氨基酚在0.295V处出现一良好的氧化峰。且乙酰氨基酚的浓度在2.0×10^(-7)～1.0×10^(-5)mol·L^(-1)范围内与峰电流呈线性关系,检出限(3S/N)为9.0×10^(-8)mol·L^(-1)。据此提出了差分脉冲伏安法测定药片中对乙酰氨基酚的含量,3个样品的测定结果与标示值相符,测得平均回收率为98.6%,相对标准偏差(n=6)均小于3.5%。

Poly-p-aminobenzene sulfonic acid modified glassy carbon electrode（GCE）was prepared by cyclic voltammetry（CV）with scanning rate of 100 mV·s^-1 in an electrolyte containing PBS of pH 7.0 and 2.0×10^-3mol·L^-1 p-aminobenzene sulfonic acid solution for 10 cycles first in the potential range of-1.5-2.5 V and then in the potential range of-1.5-1.5 V for 15 min.As shown by the result of CV study on the electrochemical behavior ACOP at the modified electrode,a pair of oxidation and reduction peaks was found giving a potential difference of 30 mV.It was shown by DPV study in PBS of pH 5.9 that a sensitive oxidation peak of ACOP was observed at the potential of 0.295 V（vs.SCE）,and linear relationship between values of peak current at this potential and concentration of ACOP was obtained in the range of 2.0×10^-7-1.0×10^-1mol·L^-1,with value of detection limit（3S/N）of 9.0×10^-8mol·L^-1,Based on these facts,the DPV method was used in the determination of ACOP in its tablets.In analyzing 3 tablet samples of the drug,results in consistency with the labelled value were obtained. Average value of recovery test obtained was 98.6%.with RSD＇s（n=6）less than 3.5%.