Common Trouble-Shooting About SPE Cartridge
SPE (Solid Phase Extraction) cartridges are widely used in analytical chemistry to extract, purify, and concentrate analytes from liquid samples. However, as with any analytical technique, there are some common troubleshooting issues that may be encountered when using other SPE products such as Reversed Phase C18A SPE Cartridges, Normal Phase PR Grade Florisil SPE Cartridges, and others. Here are some common problems associated with SPE cartridges and their potential solutions:
1. Low recovery rate
Possible reasons and solutions
1) Cartridge activation conditions are not appropriate
– Correct activation of SPE cartridges depends on the stationary phase.
2) The sample solvent has a stronger force on the target component than the stationary phase:
– Choose an SPE cartridge with stronger selectivity for the target component
– Adjust the pH value of the sample solvent to increase the force of the target component on the stationary phase
– Change the polarity of the sample solvent to reduce the force of the target component in the solvent
3) Improper cleaning solvent selection, too strong elution ability
– Use the correct cleaning solvent, choose the solvent with weaker elution ability.
4) The flow rate is too fast when loading
– Gravity natural load or control sample flow rate ≤ 1 ml/min.
5) SPE cartridge is too small
– Use larger format SPE cartridges
– Use a more selective SPE cartridge
– Use SPE cartridges with a larger loading capacity
6) SPE cartridge cleaning solvent is not sufficiently dried before elution
– Fully drain the rinse solvent.
7) The flow rate is too fast or too slow when eluting
– Control flow rate 1-2ml / min.
8) Improper column activation conditions
– Depending on the stationary phase, activate the SPE cartridge correctly:
– Reversed-phase packing
– Normal phase packing
– Ion exchange packing
9) Improper selection of cleaning solvent
– Too strong elution ability
– Use the correct cleaning solvent;
– Choose a solvent with a weaker eluting power.
10) The flow rate is too fast when loading the sample
– Natural sample loading by gravity or control sample loading flow rate ≤ 1mL/min
11) Insufficient drying of SPE column cleaning solvent before elution
– Thoroughly drain the rinse solvent
12) Insufficient elution
– Increase the volume of the eluent, increase the strength of the eluent;
– Use smaller format SPE cartridges
2. The target component cannot be eluted from the SPE cartridge
Possible reasons and solutions
1) The selectivity relative to the target component is too strong
– Select the cartridge that retains the weaker analyte;
– Select the elution solvent with a stronger elution ability.
2) SPE cartridge size is too large
– Increase the amount of eluent used
– Use smaller format SPE cartridges
3) Insufficient amount of eluent
– Increase eluent.
4) The flow rate is too fast or too slow when eluting
– Control flow rate 1-2ml / min.
5) The elution ability of the eluent is too weak
– Adjust the pH value of the eluent to improve the solvent’s ability to elute the target components (for acid and base target components)
– Change the polarity of the eluent to improve the eluting ability of the solvent for the target components
6) Fixed relative target component selectivity is too strong
– Choose the cartridge with weaker retention of the analyte
– Select an elution solvent with stronger elution ability for acid and alkali target components, adjust the pH value of the eluent, and weaken the selectivity of the fixed relative target components
3. Poor reproducibility
Possible reasons and solutions
1) The bed dried before loading
– Reactivate the cartridge
2) Exceeding the load capacity of the cartridge
– Reducing the amount of load, or using a larger SPE cartridge
3) The flow rate during the loading process is too high
– The flow rate is reduced, the gravity is naturally loaded or the flow rate of the controlled sample is ≤ 1 ml/min.
4) The elution flow rate is too fast
– The eluent is added twice
5) Insufficient amount of eluent
– Increase the amount of eluent, or use a smaller size SPE cartridge
6) The elution ability of the cleaning solvent is too strong
– Let the eluent penetrate into the small column first, then vacuumize or pressurize the small column, and control the flow rate at 1 ~ 2ml/min
4. Interfering substances are not cleaned
Possible reasons and solutions
1) The selectivity of the fixed relative interferer is too strong
– Select the appropriate cleaning solution to selectively wash away the interference
– Select the SPE cartridge that is more specific to the target component.
2) Interstitial residual interference
– Select a more specific SPE cartridge for the target component
3) The sample contains too much particulate matter
– Filter or centrifuge the sample solution before loading, or use a sample solvent with stronger dissolving power
4) The viscosity of the sample solution is too high
– Check the tightness of the extraction device, check whether the pump is working normally, and increase the vacuum
5) Insufficient vacuum
– Check the tightness of the extraction device, check whether the pump is working properly, and increase the vacuum
6. The sample size is too large
Possible reasons and solutions
The sample volume is larger than the loading amount of the extraction cartridge
– Using a larger SPE cartridge
7. Poor extraction efficiency
Possible reasons and solutions
The wrong method
– Select stationary phases with different extraction modes, or use other analytical methods
