聚L-苯丙氨酸修饰电极测定对乙酰氨基酚

采用循环伏安法制备了聚L-苯丙氨酸薄膜修饰玻碳电极,研究了对乙酰氨基酚在该修饰电极上的电化学行为,建立了循环伏安法测定对乙酰氨基酚的新方法.研究发现:在pH 7.0的磷酸盐缓冲溶液中,聚L-苯丙氨修饰电极对对乙酰氨基酚存在灵敏的氧化作用,氧化峰电位负移50 mV.对乙酰氨基酚的浓度在2.0×10-5~2.0×10-4mol.L-1和8.0×10-7~2.0×10-5mol.L-1范围内与其峰电流呈良好的线性关系,检出限为5.0×10-7mol.L-1.对1.0×10-5mol.L-1对乙酰氨基酚平行测定5次,相对标准偏差为1.6%.该法可用于药品中对乙酰氨基酚的测定,结果满意.

Voltammetric Determination of Acetaminophen at a Poly (L-phenylalanine)Modified Electrode

A poly (L-phenylalanine) modified electrode is prepared by cyclic voltammetry.The electrochemical behavior of acetaminophen on the modified electrode is studied in detail.In phosphate buffer solution (pH 7.0),the modified electrode reveals an excellent electrocatalytic activity for acetaminophen.The oxidation peak potential is reduced by 50 mV compared with that on the bare glass carbon electrode.The oxidation peak current is well proportional to the concentration of ACOP in the range of 2.0×10~(-s)~2.0× 10~(-4) mol/L and 8.0×10~(-7) ~2.0× 10~(-5) mol/L with a detection limit 5.0×10~(-7) mol/L.The relative standard deviation is estimated to be 1.6 % from the parallel determinations of 1.0 × 10~(-6) mol/L acetaminophen for five times.The modified electrode is easy to be prepared with good reproducibility and is applied to the determination of acetaminophen in drug tablets with satisfactory results.