Solid Phase Extraction (SPE) technology uses the poor ability of analytes to be adsorbed in different packing to purify the target, effectively separating the target from interferences, and greatly enhancing the analysis of analytes, especially trace analysis. The detection ability of the substance improves the recovery rate of the tested sample.
When using SPE pre-treatment, every analysis and testing engineer encounters an annoying and unpleasant problem: slow flow rate, uneven flow rate, blockage, and inability to get down; too small column would cause a collapse. With years of deep accumulation in the field of sample preparation, HAWACH shows you a few tricks to treat the problem of the slow flow of small columns.
Five steps
The basic operation of SPE includes five steps: activation, equilibration, loading, rinsing, and elution. The problem is nothing more than these steps and we’ll look at it one by one.
The basic operation of SPE includes five steps: activation, equilibration, loading, rinsing, and elution. The problem is nothing more than these steps and we’ll look at it one by one.
Activation and equilibrium
Generally, reversed-phase or ion-exchange cartridges use methanol and water to activate and equilibrate. Normal-phase cartridges use petroleum ether or n-hexane to activate equilibrium.
Generally, reversed-phase or ion-exchange cartridges use methanol and water to activate and equilibrate. Normal-phase cartridges use petroleum ether or n-hexane to activate equilibrium.
1) The packing is too tight resulting in too slow flow rate. You can speed up the flow rate by pressurizing, or purchase products from manufacturers that have strict quality control on the flow rate. HAWACH has strict quality control ranges for the flow rate of each batch of cartridges and unqualified ones will be eliminated.
2) The particle size of the packing is too small and the flow rate becomes slow. For example, florisil at 100-200 meshes will be slower than 60-100 meshes at the same activating solvent. You can select the appropriate size of the cartridge according to the type of sample matrix and usage habits.
3) The difference in column volume. These two specifications (500mg 3ml; 500mg 6ml) have different packing heights. Obviously, 500mg 6ml has a large diameter and a low filler height, and the flow rate is relatively fast. It is naturally congested and the passing rate is slow. You can choose the appropriate column according to the type of sample matrix and usage habits.
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