摘要
在乙酸 -乙酸钠 ( p H 4.2 0 )底液中 ,阿西美辛 ( ACE)在汞电极上有一线性扫描还原峰 ,峰电位 Epc=- 1 .1 8V( vs.Ag/Ag Cl) ,该峰具有明显的吸附性。吸附粒子为 ACE中性分子 ,测得 ACE在汞电极上的饱和吸附量为 1 .1 9× 1 0 - 10 mol/cm2 ,每个 ACE分子所占电极面积为 1 .43nm2 ,ACE在悬汞电极上的吸附符合 Frumkin等温式。测得吸附系数β =1 .2 9× 1 0 6 ,吸引因素γ =1 .0 4 ,电子转移数 n为 2 ,不可逆吸附的电子转移系数α为 0 .86,表面电极反应速率常数 ks=0 .32 /s。建立了吸附伏安法测定 ACE的最佳条件 ,检出限为 1 .0× 1 0 -
In a supporting electrolyte containing HAc NaAc(pH 4.20) buffer, a reduction peak of acemetacin(ACE) was observed by linear sweep voltammetry at Hg electrode. The peak showed a potential of -1.18 V(vs. Ag/AgCl) and adsorptive characteristics. The adsorbed species were the neutral molecule of ACE. The saturated adsorption amount of ACE at Hg electrode was 1.19×10 -10 mol/cm 2, and each ACE molecule occupied 1.43 nm 2. On the surface of HMDE, the adsorption of ACE obeyed Frumkin adsorption isotherm. The adsorption coefficient(β) was 1.29×10 6. The attractive factor(γ) was 1.04. The number of electrons transferred per ACE molecule(n) was 2. The transfer coefficient(α) of the irreversible adsorptive system of ACE was 0.86. The rate constant of surface electrode reaction k s was 0.32 s -1 . The mechanism of electrochemical reduction of ACE at Hg electrode was explored. The detection limit of the adsorptive stripping voltammetry of ACE was 1.0×10 -9 mol/L under optimized condition.
出处
《分析科学学报》
CAS
CSCD
北大核心
2001年第3期217-220,共4页
Journal of Analytical Science
