The separation of two peaks in terms of their average peak width at base (\(t_{\rm{R2}}>t_{\rm{R1}}\)): \[R_{\rm{s}}=\frac{t_{\rm{R2}}\,-\,t_{\rm{R1}}}{\frac{w_{\rm{b1}}\,+\,w_{\rm{b2}}}{2}}=\frac{2\ (t_{\rm{R2}}- t_{\rm{R1}})}{w_{\rm{b1}}\,+\,w_{\rm{b2}}}\] In the case of two adjacent peaks it may be assumed that \(w_{\rm{b1}}\approx w_{\rm{b2}}\), and thus, the width of the second peak may be substituted for the average value: \[R_{\rm{s}}\approx \frac{t_{\rm{R2}}\,-\,t_{\rm{R1}}}{w_{\rm{b2}}}\]