Pulse Methods:

The sensitivity of linear scan voltammetry or polarography is limited by charging current which is large initially in the drop life. The slowness, inconvenient apparatus and poor detection limits of linear scan voltammetry or polarography were the reasons for its decline. The sensitivity of these two methods is improved by pulse methods by about 6.5 times by eliminating charging current. The current in these methods is measured at a time when the difference between the Faradaic current and the interfering charging current is large. Those are four significant pulse methods namely

i)  Normal pulse voltammetry/polarography

ii) Differential pulse voltammetry/polarography

iii) Square wave voltammetry

iv) Cyclic voltammetry

A potential excitation signals used within variant voltammetric methods are given in Figure and the individual methods are discussed in the following sections.