How to Operate When the SPE Cartridge Activates the Adsorbent?
As we know, five steps required for solid phase extraction cartridge: sample preparation, activation or equilibration of the column, loading, rinsing and eluting the compound of interest. There is no uniform regulation for that the solid phase extraction cartridge should be activated, rinsed and eluted with what kind of solvent. Please refer to the national standard, pharmacopeia or proven method based on your analysis.
There are two purposes for the activation of the solid phase extraction cartridge. The first purpose is to infiltrate the packing so that the sample solution can flow through the solid phase extraction cartridge; the second aim is to clean the interference impurities and solvent residue on the SPE cartridge.
Solid-phase extraction (SPE) is usually used for the pretreatment of liquid samples, extraction of semi-volatile or non-volatile compounds, or removal of impurities in the sample that interfere with the separation analysis, and can also be used for pre-dissolution of the treatment. Solid-phase samples into solvents. SPE techniques are excellent for the extraction, concentration, and purification of analytes.
The solid-phase extraction cartridge is rinsed with a suitable solvent prior to sample extraction to keep the adsorbent moist and to adsorb the target compound or interfere with the compound. Different modes of SPE cartridge activation are different from solvents.
1. Reverse phase SPE
A weakly polar or non-polar adsorbent for reversed-phase solid-phase extraction is usually rinsed with a water-soluble organic solvent such as methanol and then rinsed with water or a buffer solution. It can also be rinsed with a strong solvent (such as hexane) prior to rinsing with methanol to eliminate impurities adsorbed on the adsorbent and its interference with the target compound.
2. Normal phase SPE
The polar adsorbent used in the normal phase SPE is usually rinsed with the organic solvent (sample matrix) in which the target compound is located.
3. Ion exchange SPE
The adsorbent used in ion exchange SPE can be rinsed with a sample solvent when used in a sample in a non-polar organic solvent; when it is used in a sample in a polar solvent, it can be rinsed with a water-soluble organic solvent. Thereafter, it is rinsed with an aqueous solution of an appropriate pH and an organic solvent and a salt.
The choice of SPE cartridges
The cartridges play an important role and there are many types of SPE cartridges. Choosing a suitable one will be the first task. In the specific experimental work, it is necessary to select a suitable packing according to the analysis object, detection means and laboratory conditions, and an SPE cartridge of suitable specifications. More importantly, we should consider the extraction capacity of the SPE cartridge for the analyte, the volume of the sample solution, the final volume of the solution after elution, and the total amount of analyte and interference in the sample solution. Generally, the total mass of the analyte and the interferent adsorbed by the adsorbent in the cartridge should not exceed 5% of the total mass of the adsorbate. The volume of the eluent is typically 2.5 times the volume of the bed of the extraction cartridge.
In order to keep the adsorbent in the SPE cartridge moist until it is added to the sample after activation, approximately 1ml of the solvent for the activation treatment should be maintained on the adsorbent after the activation treatment. If the above description cannot solve your problem, please feel free to call HAWACH +86-29-89284429 or send emails to firstname.lastname@example.org. We are here to help.