Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Iran.
Drug Test Anal. 2011 May;3(5):325-30. doi: 10.1002/dta.232. Epub 2011 Feb 9.
A sensitive and selective electrochemical method for the determination of isoproterenol (ISPT) was developed using multiwall carbon nanotubes and a room temperature ionic liquid (i.e. 1-butyl-3-methylimidazolium hexafluoro phosphate, ([C4mim]-[PF6])). This multiwall carbon nanotubes ionic liquid electrode (MWCNTILEE) is a very good alternative to previously described electrodes because the electrocatalytic effect is achieved without any electrode modification. The oxidation peak potentials in cyclic voltammogram of ISPT on MWCNTILEE was occurred around 470 mV vs Ag/AgCl (at pH 6.0) while this peak potential at carbon paste electrode was appeared around 605 mV at the same scan rate of 100 mV s⁻¹. The electrochemical parameters such as diffusion coefficient and charge transfer resistance were determined using cyclic voltammetry and electrochemical impedance spectroscopy. Under the optimized conditions, the peak current was linear to ISPT concentration over the concentration range of 1.0 to 520 µmol L⁻¹ using differential pulse voltammetry. The detection limit was 0.85 µmol L⁻¹. The proposed method was successfully applied to the determination of ISPT in both ampoules and urine samples.
一种基于多壁碳纳米管和室温离子液体（即 1-丁基-3-甲基咪唑六氟磷酸盐，([C4mim]-[PF6])）的灵敏、选择性电化学方法被开发出来，用于测定异丙肾上腺素（ISPT）。与之前描述的电极相比，这种多壁碳纳米管离子液体电极（MWCNTILEE）是一个非常好的选择，因为无需进行电极修饰即可实现电催化作用。在 pH 值为 6.0 时，ISPT 在 MWCNTILEE 上的循环伏安图中的氧化峰电位约为 470 mV 相对于 Ag/AgCl（在 pH 6.0 时），而在相同的扫描速率为 100 mV s⁻¹ 时，在碳糊电极上的这个峰电位出现在约 605 mV。使用循环伏安法和电化学阻抗谱确定了电化学参数，如扩散系数和电荷转移电阻。在优化条件下，使用差分脉冲伏安法，峰电流在 1.0 至 520 µmol L⁻¹ 的浓度范围内与 ISPT 浓度呈线性关系。检测限为 0.85 µmol L⁻¹。该方法成功地应用于安瓿和尿液样品中 ISPT 的测定。
