Hawach solid phase extraction (SPE) cartridges contain polymers, absorbents or silica gel based bonded phase packings. Solutions are passed through by using either gravity or vacuum pressure. It can be mounted on the reservoir and filter tube or configured with vacuum manifold for preparing samples. There are several steps to follow to make sure that the SPE cartridges can be used properly.
1. cartridge conditioning
Condition the SPE cartridge to activate the packing before the sample is prepared. Conditioning solvents and procedure depend on the packing and application. Identify the item number on the packaging accurately prior to the cartridge conditioning. Keep the last used conditioning solvent 1mm higher than the packing level of the cartridge, ensuring the packing stay moist. Repeat the conditioning procedure if the packing dries before the sample is added. But washed the remaining buffer salts away by water from packing first before reintroducing solvents.
Condition the SPE cartridge to activate the packing before the sample is prepared. Conditioning solvents and procedure depend on the packing and application. Identify the item number on the packaging accurately prior to the cartridge conditioning. Keep the last used conditioning solvent 1mm higher than the packing level of the cartridge, ensuring the packing stay moist. Repeat the conditioning procedure if the packing dries before the sample is added. But washed the remaining buffer salts away by water from packing first before reintroducing solvents.
2. adding the sample
The samples are then filtered and centrifuged before passing through the SPE cartridge to avoid clogging. If necessary, the pH, salt concentration and organic solvent content of the sample solution can be adjusted. Using a pipette or micropipette to transfer the sample solution accurately at the SPE cartridges can be used properly. Adjusting the flow rates of the solution to an appropriate speed. The flow rate should not exceed 5mL/min in general.
The samples are then filtered and centrifuged before passing through the SPE cartridge to avoid clogging. If necessary, the pH, salt concentration and organic solvent content of the sample solution can be adjusted. Using a pipette or micropipette to transfer the sample solution accurately at the SPE cartridges can be used properly. Adjusting the flow rates of the solution to an appropriate speed. The flow rate should not exceed 5mL/min in general.
3. washing the packing
If the desired compounds are retained in the packing, wash off unwanted residues with solutions that will not remove the target compounds. Then use the sample solvent to wash un-retained materials from the SPE cartridge. It is generally considered to be aiming to keep the volume of wash solution less than a cartridge volume.
If the desired compounds are retained in the packing, wash off unwanted residues with solutions that will not remove the target compounds. Then use the sample solvent to wash un-retained materials from the SPE cartridge. It is generally considered to be aiming to keep the volume of wash solution less than a cartridge volume.
If the desired compounds are un-retained in the packing, use sample solvent to remove any residual desired material from the cartridge. Then complete the elution step as wash step again to finish the extraction procedure.
4.eluting the desired compounds
Using a small volume of a solution elute desired compounds, but leaves behind any impurities not removed in the last step. Collection of eluate as the further prepared sample solution. Keep each aliquot is in contact with the packing for 30 sec. to 1 min is necessary for the best recovery.
Using a small volume of a solution elute desired compounds, but leaves behind any impurities not removed in the last step. Collection of eluate as the further prepared sample solution. Keep each aliquot is in contact with the packing for 30 sec. to 1 min is necessary for the best recovery.
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