Waters PoraPak RXN Cartridges - Manual (Page 3)

[ Care and Use ManUal ]
PoraPak ™ RXN Cartridges and Bulk Care & Use 3
II. protoCols
Using PoraPak Rxn CX: Strong Cation-Ion Exchange Catch-and-Elute and Pass-Through Protocols
For PoraPak Rxn RP: Reversed-Phase Protocol
Catch and Elute Pass Through
Adsorption
Wash Step
100%-methanol
fraction contains
more impurities,
acids and neutrals
Elution Step
5% ammoniated
methanol – fraction
contains bases
Condition Step
100% methanol
Load Step
Fraction collected
contains acids,
neutrals and
reaction solvent
Wash Step
100%-methanol
fraction contains
acids and neutrals
Recombine Load
and Wash Steps
Condition with an organic solvent such as methanol.
This step is important to wet the sorbent.
Pour the reaction mixture into the cartridge.
Let the reaction mixture flow by gravity.
Catch-and-Elute Strategy –
elute bases using 5% ammoniated methanol.
Pass-Through Strategy – the retained compounds are unwanted
reaction components; no need for further elution step.
Catch-and-Elute Strategy – the wash step contains
unwanted reaction components.
Pass-Through Strategy – the analytes of interest are unretained
and are eluted in the wash. Combine the fraction collected
in the load step with this wash fraction.
Pass-Through Strategy – the analytes of interest are unretained
Catch-and-Elute Strategy –
analytes are retained by ion-exchange interaction.
Wash with 100% methanol.
Condition Step
100% methanol
Load Step
Fraction collected
contains acids,
neutrals and
reaction solvent
Condition the sorbent with polar organic solvent, preferably
the polar organic solvent used in the reaction. Follow with
an equilibration step using organic/water solvent,
containing no less than 75% water.
Designed to only remove the undesired reaction
components, not the analytes.
Pour the reaction mixture into the cartridge.
Let the reaction mixture flow by gravity.
Wash with a stronger solvent to elute the compound(s) of interest.
Generic protocol – Load water:organic solvent
(at least 3:1). Fraction collected contains polar compounds.
Generic protocol – Condition with methanol followed by water.
Generic protocol
Wash 1 – Water. Fraction contains polar compounds.
Wash 2 – Water:methanol (1:1). Fraction collected contains
less polar compounds.
Generic protocol – Methanol. Fraction collected
contains hydrophobic compounds.
Condition Step
Load Step
Wash Step
Elution Step
For a compound to be retained, a
reaction, carried out in a polar organic
solvent will have to be concentrated by
evaporation and/or diluted with water
(3-to-1 or greater). This dilution brings
the organic content down to 25% or
less so as to enable reversed-phase
retention. The generic protocol, shown
to the right, can be used as a starting
point to clean up reaction mixture.