IC: Make it clear the anions are covalently bonded eg sulphonate
but the cations are attached ionically.
ECD: standing current (produced from beta radiation hitting CH4 in
the carrier gas) is disrupted when electrophilic Cl
atoms capture electrons – size of disruption indicates the amount
of OC present.
Hybrid columns: Xterra (Waters) takes methylated silica which
behaves in-between a polymer and a silica support.