interstitial fraction

in chromatography
https://doi.org/10.1351/goldbook.I03120
The @I03122@ per unit volume of a packed column. Defined by: \(\varepsilon_{\text{I}}=\frac{V_{\text{I}}}{X}\) where \(V_{\text{I}}\) is the interstitial volume and \(X\) the @C01183@.
Source:
Orange Book, 2nd ed., p. 100 [Terms]