Several Problems Affecting the Flow Rate of SPE Cartridges

The basic operation of SPE cartridges includes five steps: activation, balance, sampling, washing, and elution. Generally speaking, those matters affecting the velocity of the SPE cartridges arise in these steps. Here we especially talk about the process of activation and balance. In that process, people fill out the fillers first. In general, reversed-phase or ion-exchange columns are activated and balanced by methanol and water respectively, while normal-phase columns are activated by petroleum ether or n-hexane.

First, filling too tight results in a slow flow rate. People can solve these matters by increasing the flow rate under pressure or purchasing products from manufacturers with strict quality control of the convection rate.

Second, when the size of the fillers is smaller, the flow rate will be slower. People need to select the proper size of columns according to the type of sample matrix and the usage habit.

The third is the difference in the pipe volume. Obviously, the large diameter and the low height of the fillers mean a fast flow rate. The selection of the columns with suitable pipe volume is also based on the type of sample matrix and the usage habit.

There are many types of SPE cartridges. In the specific experimental work, it is necessary to select suitable packing and reasonable specifications of solid-phase extraction cartridges according to the analysis object, detection methods, and laboratory conditions. We should consider the extraction ability of the solid-phase extraction cartridge for the analysis object, the volume of the sample solution, the final volume of the solution after elution, and the total amount of the analyte and the interferent in the sample solution.

Matters need attention

SPE Cartridge provided by Hawach Scientific is of high retention rate, uniform flow rate, and excellent stability. For better operation and application, there are some tips for attention. The recovery rate of the samples would be affected by inappropriate column activation conditions, too fast or too slow flow rate, improper action force of the sample solvent on the target compound, improper selection of cleaning solvent, and improper sample loaded rate. Besides, the target compounds cannot be eluted from the SPE Cartridge will be caused by too strong selectivity of fixed relative target components.

HAWACH SPE cartridges

Over the years, through the efforts of scientific and technological workers, Hawach has a wide range of products including organic element analysis, sample preparation, electrochemistry, physical optics, gas phase ion mobility spectrometry, spectroscopy, and chromatography. There are different specifications of SPE cartridges to meet various demanding experimental requirements. Moreover, they can be customized based on your specific requirements.

C8 SPE cartridges Suppliers
SPE Cartridges C18
SPE Columns Chromatography

Several Problems Affecting the Flow Rate of the Hawach SPE Cartridges

The flow rate of Solid Phase Extraction (SPE) cartridges can be affected by several factors. Here are some common problems that may impact the flow rate, along with possible solutions:

  1. Clogging of Sorbent:
    • Problem: The sorbent material in the SPE cartridge may become clogged with particulate matter from the sample, leading to reduced flow rates.
    • Solution: Use a proper pre-filtration step to remove large particles from the sample before loading it onto the cartridge. Additionally, ensure that the sample is properly conditioned and loaded onto the cartridge according to the manufacturer’s recommendations.
  2. Air Bubbles in Cartridge:
    • Problem: Air bubbles trapped within the sorbent bed can hinder flow.
    • Solution: Carefully load the sample onto the cartridge to minimize the introduction of air bubbles. Slowly apply the vacuum or positive pressure to prevent air entrapment.
  3. Improper Conditioning:
    • Problem: Inadequate or incorrect conditioning of the SPE cartridge can lead to flow rate issues.
    • Solution: Follow the recommended conditioning steps provided by the manufacturer. This typically involves passing specific solvents through the cartridge to activate and equilibrate the sorbent.
  4. Incorrect Flow Rate Setting:
    • Problem: Incorrect settings on the vacuum or positive pressure system can affect the flow rate.
    • Solution: Adjust the vacuum or pressure settings within the recommended range for the specific cartridge and application.
  5. Sorbent Saturation:
    • Problem: The sorbent bed may become saturated with analytes, leading to reduced flow rates.
    • Solution: Use the appropriate cartridge size and sorbent bed mass for the sample volume and analyte concentration. If needed, perform a solvent rinse or elution step to help recover analytes.
  6. Improper Solvent Choice:
    • Problem: Using solvents that are too viscous or have high surface tension can impede flow.
    • Solution: Choose solvents that are compatible with the SPE sorbent material and have properties conducive to efficient flow.
  7. Column Damage or Irregularities:
    • Problem: Physical damage to the SPE cartridge or irregularities in the sorbent bed can disrupt flow.
    • Solution: Inspect cartridges for visible damage before use. If irregularities are suspected, contact the manufacturer for guidance.
  8. Column Over-Packing:
    • Problem: Packing the sorbent bed too tightly can impede flow.
    • Solution: Follow the recommended packing procedures provided by the manufacturer. Avoid excessive force when packing the cartridge.
  9. Sample Volume and Viscosity:
    • Problem: High sample viscosity or volume may lead to slower flow rates.
    • Solution: Use the appropriate cartridge size and sorbent bed mass for the sample volume and characteristics. Consider dilution if necessary.
  10. Improper Storage:
    • Problem: Improper storage conditions can lead to sorbent degradation or clumping, affecting flow.
    • Solution: Store SPE cartridges in a cool, dry place according to the manufacturer’s recommendations.

Regularly inspecting and maintaining SPE cartridges, following manufacturer instructions, and optimizing the method for specific sample characteristics can help address and prevent flow rate issues. If problems persist, consider consulting with technical support from the cartridge manufacturer for further assistance.

When you use Reversed Phase C18 SPE Cartridge, Normal Phase PR Grade Florisil SPE Cartridges, and other SPE cartridges, there are several problems affecting the flow rate.

The first is the incorrect order of putting solvents. For example, if we take the water as an activating solvent for the reversed-phase column, the flow rate will be very slow. The reason for the phenomenon is that water has poor wettability to hydrophobic reversed-phase filler. Water is not as activated as methanol. Be careful when adding the solvents.

The second is insoluble activation and equilibrium solvents. When you try to use dichloromethane to activate and water to balance, you will see that the flow rate will slow down after adding water. This is due to the poor mutual solubility between water and dichloromethane, which can be solved by adding the transition solvent methanol. Methanol can be soluble in dichloromethane or water.

The third is the air in the fillers. The SPE cartridge is composed of a sieve plate, filler, and column tube. It is not organic. Therefore, there will be a slight loosening in the process of transportation, especially long-distance transportation, which leads to air entering the filler. And it is generally not easy to be found by the naked eye. It is easy to understand why there will be a slightly uneven flow rate of the same batch of columns. Dealing with this, you can use the SPE device to extract air by adding plus positive pressure, and then add the solvent together.