碳纳米管修饰玻碳电极循环伏安法测定醋酸地塞米松

摘要

建立了碳纳米管修饰玻碳电极循环伏安法测定醋酸地塞米松的方法.在pH值为2.2的邻苯二甲酸氢钾 –盐酸(KHP–HCl)缓冲溶液中,以经过1 mg/mL碳纳米管(CNTs)修饰的玻碳电极(GCE)为工作电极,采用循环伏安法扫描试样溶液,记录扫描图谱的峰电位和峰电流.醋酸地塞米松在0.85 V附近呈现较明显的氧化峰且浓度在8×10–6～7×10–4 mol/L范围内与峰电流呈良好的线性关系,相关系数为0.9990,检出限为3.3×10–7 mol/L.用该方法测定护肤品中醋酸地塞米松的含量,在干扰物质共存的情况下的回收率为87.5％～116.3％,测定结果的相对标准偏差为1.8％～3.9％(n=5).CNTs–GCE对醋酸地塞米松有较好的电化学响应,灵敏度较高,可应用于化妆品、药品中醋酸地塞米松的测定.%The method for determination of dexamethasone acetate by carbon nanotubes modified glassy carbon electrode–cyclic voltammetry was established. In potassium acid phthalate–hydrochloric acid buffer solution (pH 2.2), a glassy carbon electrode which was modified by 1 mg/mL carbon nanotubes was used as working electrode, the solution was scanned by using cyclic voltammetry and the peak potential and current were recorded. Dexamethasone acetate showed a oxidation peak at 0.85 V,the peak current and concentration of dexamethasone acetate in the range of 8×10–6–7×10–4 mol/L showed a good linear relationship with correlation coefficient of 0.9990 and the detection limit was 3.3×10–7 mol/L. This method was applied to determine dexamethasone acetate in face toner with the recoveries of 87.5％–116.3％, the relative standard deviation of determination results was 1.8％–3.9％(n=5) under the presence of interfering substances. The carbon nanotubes modified glassy carbon electrode show good response and high sensitivity for dexamethasone acetate, which could be applied to determination of dexamethasone acetate in cosmetics and pharmaceuticals.