Peak resolution also considering the molar masses (
\(M_{1}\),
\(M_{2}\)) of the two test compounds:
\[R_{\rm{sp}} = \left[\frac{V_{\rm{R1}} - V_{\rm{R2}}}{(w_{\rm{b1}} + w_{\rm{b2}})/2} \right] \cdot \left[ \frac{1}{\log (M_{2}/M_{1})} \right]\]Notes: - The test compounds used for the determination of the specific resolution should have a narrow molecular-mass distribution (the ratio of the mass-average and number-average molecular masses should be equal to or less than about \(\pu{1.1}\)) and differ by a factor of about \(\pu{10}\) in their molar masses.
- In some areas, the symbol \(R_{\rm{s}}\) is used for the specific resolution. Due to the possibility of confusing it with the general resolution term (see peak resolution), the symbol \(R_{\rm{sp}}\) is suggested here.
Source:
PAC, 2017, 90, 181. 'Terminology of separation methods (IUPAC Recommendations 2017)' on page 212 (https://doi.org/10.1515/pac-2017-0111)