硫唑嘌呤在聚合L-丝氨酸修饰玻碳电极上的电化学行为及其测定

Eelectrochemical Behavior of Azathioprine on Poly(L-serine) Modified Glassy Carbon Electrode and Its Determination

本文研究了硫唑嘌呤在聚L-丝氨酸修饰电极上的电化学行为。在pH6．0的磷酸盐缓冲溶液中，硫唑嘌呤在该修饰电极上呈现2个还原峰和1个氧化峰，其峰电位都随着PH值的增加而负移。采用线性扫描伏安法测定硫唑嘌呤，对于Ep=-0．65V处还原峰，峰电流与其浓度在1．0×10^-7～5．0×10^-5mol／L范围呈良好的线性关系，其线性回归方程为ip（μA）=0．9632＋0．8371c（μmol／L），检出限为1．0×10^-8mol／L。该方法用于尿样中硫唑嘌呤的测定，结果满意。

The glassy carbon electrodes modified with electropolymerized film of L- serine in pH 7. 0 phosphate buffer solution （PBS） were investigated by cyclic vohammetry. The modified electrode showed an excellent electrocatalytical effect on the reduction of azathioprine （AZA）. Under the experimental conditions,a pair of redox peaks of AZA at about -0.15 V and a well-defined reduction peck at- 0. 65 V （vs, SCE） were observed at the modified electrode. The peak potential shifted negatively with increase of pH value. In the PBS of pH 6. 0,the cathodic peak current （at -0.65 V） was increased linearly with the concentration of AZA in the range of 1.0× 10^- 7-5.0× 10^-5mol/L. The detection limit was 1.0 × 10^-8 mol/L. The results showed that the modified electrode could be applied to the determination of AZA in the urine sample with good results.