对乙酰氨基酚在n-丁基吡啶六氟磷酸盐修饰碳糊电极上的灵敏测定

摘要

将离子液体(n-丁基吡啶六氟磷酸盐,[BuPy][PF6])与石墨粉混合,制备了离子液体修饰碳糊电极(CILE).在0.1mol/L醋酸盐缓冲溶液中(pH 4.7),采用循环伏安法(CV)、方波伏安法(SWV)及计时库仑分析法研究了对乙酰氨基酚的电化学行为.结果表明:CILE对对乙酰氨基酚的氧化还原具有明显的电催化作用；在0.1 V/s扫速下,对乙酰氨基酚的氧化还原峰峰电位差(△Ep)为88mV；扩散系数(D)为1.214×10-7 cm2/s.对乙酰氨基酚的氧化峰电流与其浓度在0.5～10.0μmol/L范围内呈线性关系(r＝0.998 8),检出限为0.01 μmol/L( S/N＝3).该修饰电极成功用于片剂与尿样中对乙酰氨基酚含量的检测,且具有制作成本低、稳定性好、易于重复和制备等特点.%A carbon ionic liquid electrode (CILE),which was fabricated by mixing hydrophobic room temperature ionic liquid,n-butyl pyridinium hexafluophosphate ( [ BuPy ] [ PF6 ] ),with graphite powder,was used to investigate the electrochemical behaviors of paracetamol in 0.1 mol/L acetate buffer solution ( pH 4.7 ) by cyclic voltammetry (CV),square wave voltammetry (SWV) and chronocoulometry.The peak-to-peak potential separation (△Ep,) of paracetamol was 0.088 V with scan rate of 0.1 V/s.The results showed that CILE exhibited better electrocatalysis for redox of paracetamol.Diffusion coefficient (D) was calculated as 1.214 × 10-7 cm2/s.The oxidation peak current versus concentration of paracetamol at CILE showed linearity in the range of 0.5-10.0 μmol/L (r =0.998 8) with a detection limit of 0.01 μmot/L ( S/N = 3).The proposed method was applied to determination of paracetamol in tablets and urine samples successfully.In addition,CILE was inexpensive,stable,repeatable and easy to be fabricated.