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When a substance is expected to be separated by charged size exclusion chromatography it's separated by Dual mechanism ( Size exclusion + ion exchange )0
Supercritical fluid may be liquified O2 OR Liquified N2 which are used as Mobile phases when liquified under pressure
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Mechanism of bonded phase chromatography is mixed mechanism ( adsorption + partition ) ,while that of affinity chromatography is Key & lock mechanism 0
When silica heated over 400 c it's Dehydrated ( loss of OH groups & NOT DEACTIVATED) as the active silanol groups are removed & it's converted into siloxane 0
Deactivation is done by addition of calculated amount of water, so heating over 400 c NOT make deactivation, but we say DEHYDRATION
Also Activation of silica means it's the st.phase i.e adsorption occurs, while it's deactivation means silica is used only as a solid support i.e the st.phase is adsorbed on silica surface & act by partition
Alumina may be used for separation of polar comounds , cationic compounds & anionic compounds as it can be used as cationic exchanger or anionic exchanger in ion exchange chromatography according to pH 0