单壁碳纳米管修饰电极循环伏安法测定盐酸利多卡因
Voltammetric Determination of Lidocaine Hydrochloride with Single-Wall Carbon Nanotubes Modified Electrode
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摘要: 将单壁碳纳米管(SWCNT′s)分散在10 g·L-1十二烷基磺酸钠溶液中并滴涂在玻碳电极表面,红外灯烘干后,制备了单壁碳纳米管修饰电极。采用循环伏安法研究了盐酸利多卡因在修饰电极上的电化学行为。结果表明:盐酸利多卡因在该修饰电极上出现了一个灵敏的氧化峰,其峰电流比在裸玻碳电极上增大了5倍。据此提出了用循环伏安法测定盐酸利多卡因的方法。盐酸利多卡因的浓度在0.9~50.0 μmol·L-1范围内,氧化峰电流与其浓度呈线性关系,检出限(3S/N)为0.3 μmol·L-1。修饰电极用于盐酸利多卡因注射液中盐酸利多卡因的测定,测定值与标示值相符,加标回收率在98.0%~105%之间。Abstract: To prepare single-wall carbon nanotubes modified glassy carbon electrode (designated abbreviately as SWCNT′s/GCE), a dispersion of SWCNT′s in 10 g·L-1 SDBS solution was added dropwise onto the surface of GCE, and dried by infrared radiation. Electrochemical property of the modified electrode was studied by cyclic voltammetry. It was found that a sensitive oxidation peak given by lidocaine hydrochloride was observed at SWCNT′s/GCE and that the magnitude of peak current was enhanced by 5 times as compared with the bare GCE. Based on these findings, a selective method for determination of lidocaine hydrochloride by cyclic voltammetry was proposed. Linear relationship between values of oxidation peak current and concentration of lidocaine hydrochloride was ranged from 0.9 to 50.0 μmol·L-1, with detection limit (3S/N) of 0.3 μmol·L-1. The proposed method was used in the determination of lidocaine hydrochloride in injection samples, giving results in consistency with the labeled values. Recovery of the method was tested by standard addition method, and values of recovery found were in the range of 98.0%-105%.