司帕沙星在单壁碳纳米管修饰电极上的电化学行为及其测定
Electrochemical Behavior of Sparfloxacin at SWCNT-film Modified Glassy Carbon Electrode and Its Application to the Determination of Sparfloxacin
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摘要: 运用循环伏安法和线性扫描伏安法研究了司帕沙星在单壁碳纳米管修饰电极上的电化学行为,提出了一种简便、准确、灵敏的检测药物司帕沙星的电化学分析方法.在pH 6.0的0.1 mol·L-1 Na2HPO4-NaH2PO4缓冲溶液中,司帕沙星在单壁碳纳米管修饰电极上于1.06 V电位处有一峰形很好的氧化峰.在最佳的试验条件下,该氧化峰电流与司帕沙星的浓度分别在1.1×10-6~2.2×10-5mol·L-1和2.7×10-5~1.6×10-4mol·L-1范围内呈线性关系.在开路富集30 s的条件下测得方法的检出限(3S/N)为5.0×10-7mol·L-1.电极上的吸着物质经循环伏安扫描即可除去,从而使电极活性恢复,在SPFX浓度为4.0×10-5mol·L-1的浓度水平下用同一电极连续测定10次,求得相对标准偏差为5.1%,取片剂样品按提出方法分析,测定值与标示值相符.在此基础上用标准加入法作回收试验,测得回收率在97.6%~105.7%之间.Abstract: Electrochemical behavior of sparfloxacin (SPFX) at the single wall carbon nanotube (SWCNT) film modified glassy carbon electrode (GCE) was studied thoroughly by cyclic voltammetry and linear sweeping voltammetry.In a 0.1 mol·L-1 Na2HPO4-NaH2PO4 buffer solution of pH 6.0,a well-defined oxidation peak was observed at 1.06 V,and linear relationships between values of oxidation peak current and concentration of SPFX were obtained in 2 range sections,i.e.,from 1.1×10-6 to 2.2×10-5mol·L-1 and from 2.7×10-5 to 1.6×10-4mol·L-1.Detection limit (3S/N) of the method found under the condition of open-circuit accumulation for 30 s was 5.0×10-7mol·L-1.Adsorbed substances on the surface of the modified electrode were removed by cyclic voltammetric sweeping and thus making the electrode activity recovered.Ten determinations of SPFX with a same electrode at the concentration level of 4.0×10-5mol·L-1 were made to test for its precision,giving value of relative standard deviation of 5.1%.In analyzing a sample of SPFX tablet by the proposed method,the results obtained were in consistency with the labelled value.Test for recovery was made by the standard addition method based on the matrix of tablet sample,values of recovery found were in the range of 97.6%-105.7%.