摘要
考察了在NH_3-NH_4Cl底液中,那碎因的示波极谱行为。在pH 9.5的NH_3-NH_4Cl底液中该体系有一灵敏的导数极谱波,峰电位E=-1.51V(vs.SCE),峰电流i_p与那碎因浓度在0.10～7.0 μmol·L^(-1)范围内成正比,检测限为0.02 μmol·L^(-1)。用多种电化学方法确定那碎因在汞电极上的还原是属于反应物弱吸附的不可逆过程,吸附型体为中性分子,测得其在汞电极上的饱和吸附量Γ=0.781×10^(-10)mol·cm^(-2),电子转移数n=2,不可逆过程电子转移系数=0.56,扩散系数D=7.59×10^(-6)cm^2·s^(-1),电极反应速率常数k=8.32μm·s^(-1),并提出了电极反应机理。
AA sensitive irreversible reduction wave of narceinum is found in NH_3-NH_4Cl buffer(pH=9.5). This reduction wave can be used to determine trace narceinum by single-sweep oscillopolarography. The peak potential is -1.46V(vs. SCE). The derivative peak height is linearly proportional to the concentration of narceinum in the range of 0.1～7.0μmol·L^(-1). The detection limit is 0.02μmol·L^(-1). The electrocapillary, cyclicvoltammetry and normal pulse polarography etc. showed that its adsorptive characteristics is of neutral molecule and it belongs to irreversible reactant weak adsorptive system, the number of transfer elecron n is 2. The transfer coefficient α is 0.56. The diffusion coefficient D is 7.59μm·s^(-1) and the electrode reaction rate constant k is 832μm·s^(-1).The electrode mechanism is proposed.
出处
《北京师范大学学报（自然科学版）》
CAS
CSCD
1992年第4期521-526,共6页
Journal of Beijing Normal University(Natural Science)
基金
国家自然科学基金
关键词
那碎因
极谱
吸附
电化学
narceinum
polarography
adsorption
Electrochemical behaviour
