What’s SPE Method?

Solid phase extraction is a sample preparation method based on chromatographic analysis. Solid phase extraction consists of two different phases, one is a solid phase for adsorbent with a certain functional group and another is a liquid phase for sample and solvent. Its working process is like this: a solid phase extraction device (extraction column, extraction membrane, extraction nozzle, etc.), and this device is filled with a solid adsorbent under positive pressure, negative pressure, or gravity.

Solid Phase Extraction (SPE) is a sample preparation technique widely used in analytical chemistry to isolate, purify, and concentrate specific compounds from complex mixtures. The method involves the use of a solid sorbent material to selectively retain analytes while undesirable components are washed away. The retained analytes are then eluted from the sorbent for further analysis. Here is a general overview of the SPE method:

Basic Steps in SPE

  1. Conditioning:
    • The SPE cartridge or disk is initially conditioned by passing a solvent through it. This prepares the sorbent for the sample by removing any impurities and ensuring consistent interactions with the analytes.
  2. Sample Loading:
    • The sample, dissolved in a suitable solvent, is loaded onto the SPE cartridge. The sorbent selectively retains the target analytes based on their chemical properties, while other components pass through.
  3. Washing:
    • Unwanted impurities are washed away from the sorbent bed using one or more washing solvents. This step helps remove interfering substances and improves the purity of the retained analytes.
  4. Drying:
    • After washing, the sorbent is typically dried to remove any residual washing solvents. Drying ensures that the retained analytes are concentrated and ready for elution.
  5. Elution:
    • The analytes of interest are eluted from the sorbent using an elution solvent. This solvent disrupts the interactions between the analytes and the sorbent, allowing the analytes to be collected in a concentrated form.
  6. Evaporation (Optional):
    • In some cases, the eluate may undergo evaporation to further concentrate the analytes before analysis.

Key Considerations

  • Sorbent Selection:
    • The choice of sorbent depends on the chemical properties of the analytes and the sample matrix. Common sorbents include silica, bonded silica phases, polymer-based materials, and more.
  • Solvent Selection:
    • Different solvents are used for conditioning, sample loading, washing, and elution. Solvent selection is crucial for optimizing selectivity and efficiency in the extraction process.
  • Sample Compatibility:
    • Consider the compatibility of the sample matrix with the chosen sorbent and solvents. Some sample matrices may require additional sample preparation steps to ensure optimal SPE performance.
  • Flow Rate:
    • Controlling the flow rate during each step is essential for the efficiency of the SPE process. It influences the contact time between the sample and the sorbent, affecting the extraction efficiency.
  • Column Capacity:
    • Ensure that the SPE column has sufficient capacity to handle the sample size and concentration levels. Overloading the column may lead to poor recovery or decreased column lifetime.
  • Elution Volume:
    • Adjust the elution volume to achieve the desired analyte concentration. Concentrated eluates are often preferred for sensitive analytical techniques.
  • Reproducibility:
    • Maintaining consistent conditions and procedures is critical for achieving reproducible results. This includes using standardized volumes, flow rates, and solvents.

SPE is widely employed in various analytical applications, including environmental analysis, pharmaceutical analysis, food and beverage testing, and clinical research. The method offers advantages such as improved selectivity, reduced interference, and enhanced sensitivity in analytical assays.

Where we can use the SPE method?

Environmental protection analysis, food analysis, drug analysis, expert testimony, life science field, etc.

Why do people prefer to use the SPE method?

First sample pretreatment is a very very important step for every experiment. There are data shows that during a whole sample analysis test, sample pretreatment takes 61% of the importance of the whole process which occupies the first position. 27% of data processing follows behind, and sampling and analyzing both have the same percentage of importance as 6%.

Are there any advantages of the SPE method?

Sure, there are lots of advantages of using the SPE method, no emulsification phenomenon, automation, consistent results, perfect reproducibility, saving reagents, and better selectivity by changing paddings.

HAWACH SPE Cartridges offer various types such as Reversed Phase C8 SPE Cartridges, Normal Phase Diol SPE Cartridge which can suit all your laboratory requirements. You can ask us for more information at info@hawach.com.