The Ilkovic equation is used in polarography to relate the diffusion current ($i_d$) to the concentration of electroactive species in solution. The equation is given as:
\[ i_d = 607 \, n D^{1/2} m^{2/3} t^{1/6} C \]
Where:
- \( i_d \) = diffusion current (in microamperes)
- \( n \) = number of electrons transferred
- \( D \) = diffusion coefficient of the analyte
- \( m \) = rate of mercury flow (mass flow rate)
- \( t \) = drop time of mercury from DME (dropping mercury electrode)
- \( C \) = concentration of the analyte
Here, \( m \) (sometimes represented as \( m' \)) specifically denotes the mass flow rate of mercury, which determines how much mercury is flowing out of the capillary per unit time during the polarographic analysis. This parameter affects the size and frequency of mercury drops and influences the current measured.