Polarography First voltammetric technique Differs from hydrodynamic unstirred (diffusion dominates) dropping Hg electrode (DME)is used as working electrode current varies as drop grows then falls off DME current,i lifetime of drop stime
20 A -0.6 -12
How it works The average response is then used for subsequent data analysis
Polarographic data Two types of information are obtained. diffusion arrent 62 halfwave potential E12
极谱波可以用I ~ Ｖ外曲线表示，也可以用i ~ Ede曲线来表示，从下面的讨论可以看出，二者 是基本重合的。 V = ( ESCE -Ede ) + i R ∵ R are very little in polarographic electrolysis V = ESCE － Ede = －Ede( vs. SCE) 极限扩散电流Id与浓度成正比——定量分析的 基础； 半波电位E1/2与浓度无关——定性分析的基础
极谱波可以用I ~ Ｖ外曲线表示，也可以用i ~ Ede曲线来表示，从下面的讨论可以看出，二者 是基本重合的。 V = ( ESCE -Ede ) + i R ∵ R are very little in polarographic electrolysis V = ESCE － Ede = －Ede( vs. SCE) 极限扩散电流Id与浓度成正比——定量分析的 基础； 半波电位E1/2与浓度无关——定性分析的基础