PCA/GC电极同时测定尿酸(UA)和抗坏血酸(AA)

制备聚肉桂酸(PCA)修饰电极(PCA/GC),研究尿酸(UA)和抗坏血酸(AA)在该电极上的电化学行为.结果表明,在UA和AA共存体系中,UA、AA在PCA/GC电极上氧化峰电流增大且峰电位分别负移至50mV、330mV,二者相差280mV,据此可同时检测UA和AA.在pH6.0磷酸盐缓冲液中,UA、AA的氧化峰电流与其浓度分别在2.0×10-6～1.0×10-4mol·L-1、2.0×10-5～6.0×10-4mol·L-1范围内呈线性关系.该电极重现性好,适用于尿样中UA的检测.

Simultaneous Determination of Uric Acid(UA) and Ascorbic Acid(AA) at PCA/GC Electrode

Poly(cinnamic acid)-modified electrode (PCA /GC) was prepared by potentiostatic technique and was used for determination of uric acid (UA),ascorbic acid (AA),and their mixture by cyclic voltammetry. This modified electrode exhibited a potent and persistent electron-mediating behavior followed by well-separated oxidation peaks toward UA and AA at a scan rate of 50 mV·s-1 with a potential difference of 280 mV,which is large enough to determine UA and AA individually and simultaneously. The catalytic peak current obtained was linearly dependent on the UA and AA concentrations in the range of 2.0×10-6~1.0×10-4 mol·L-1,2.0×10-5~6.0×10-4 mol·L-1 in 0.03 mol·L-1 phosphate buffer (pH 6.0),respectively. The PCA /GC electrode showed good repeatability and could be used for determination of UA in urine samples.