2 Main Aspects to Be Considered for the Choice of SPE Cartridge

SPE and SPE cartridge

Developed on the basis of traditional liquid-liquid extraction, the solid phase extraction(SPE)’s working principle is based on similar mutual solubility and similar interaction between substances, and in combination with the widely used basic knowledge of liquid chromatography and gas chromatography stationary phase. The solid phase extraction device is a widely used and popular sample pretreatment technology that uses solid adsorbents to adsorb target compounds in liquid samples, separate them from the matrix and interfering compounds of the sample, and then reuse them. The eluent is eluted or heated to desorb to achieve the purpose of separating and enriching the target compound.

Any part of the SPE cartridge that can be in contact with the sample will contaminate the end sample if impurities dissolve. Therefore, the material of each part has an explanation for the HAWACH SPE cartridge, namely: SPE is composed of a medical PP empty tube, medical PE sieve, and fixed adsorbent (also called stationary phase). HAWACH SPE cartridges have the characteristics of strong corrosion resistance and low impurity content, so the impurity dissolution probability is low and has an excellent purification function. The solid phase extraction cartridge is a widely used and increasingly popular sample pretreatment tool. It has been widely used in food, environment, pharmaceutical, and other industries and has become one of the effective means of sample pretreatment and purification. SPE cartridge mostly uses gravity to flow down by itself or it is combined with an SPE device to accelerate the separation speed by vacuuming. Today, we will discuss how to choose the cartridge and how to use it.

Mixed Mode SPE Cartridge C8 SPE Columns C8 SAX SPE Cartridges

2 main aspects to be considered for the choice of SPE cartridge

Different kinds of SPE cartridges are available. We need to consider the detection methods, analytical objects, and laboratory conditions to choose suitable packing and reasonable specifications in actual experiments. In general, two aspects need to be considered when choosing the solid phase extraction cartridge: the choice of adsorbent and cartridge specifications.

The adsorbent of SPE cartridges

1. The adsorbent can be selected mainly according to the properties of the target compound and the properties of the matrix.
Appropriate adsorption packing can make the interfering substance and the target component get good separation and meet the recovery requirements. But, the compound quality which can absorb the adsorbent is limited. Overload will occur if there is too large a sample volume and makes the target without being retained penetrating the extraction cartridge. The choice of adsorbent can be roughly selected by the above two methods.

2. Choice of SPE Adsorbent:

  • Type of Analyte: Consider the chemical nature of the target analyte. Different adsorbents have varying affinities for different types of compounds (e.g., polar, non-polar, acidic, basic).
  • Compatibility with Sample Matrix: Ensure that the adsorbent is compatible with the nature of your sample matrix. Some samples may require specific types of adsorbents to achieve optimal extraction.
  • Selectivity: Certain adsorbents may exhibit selectivity towards specific compounds. Consider whether selectivity is a critical factor in your extraction process.
  • Capacity and Retention: Evaluate the adsorbent’s capacity to retain the analyte of interest. This helps determine how efficiently the compound will be extracted from the sample.
  • Chemical Stability: The adsorbent should be stable and not react with the sample or solvent used in the extraction process.

3. In addition to the appropriate adsorbent, selecting the appropriate cartridge specifications is also important based on the sample volume required for the verification.
Because the adsorbent of the extraction cartridge can adsorb the quality of the compound is limited, once this value is exceeded, the target substance cannot be effectively retained, which greatly reduces the elution effect. Therefore, it is necessary to select the appropriate cartridge specifications according to the number of components in the sample.

The adsorption capacity of the SPE cartridge packing is what we called the capacity. Generally, the silica-based SPE cartridge’s capacity is 1~5 mg/100 mg, equal to mass packing’s 1%~5%. The capacity of the bonded silica gel ion exchange adsorbent filler is expressed in meq/g, that is, the capacity of each gram of filler is X milliequivalents. Generally, this kind of filler’s capacity is 0.5 to 1.5 meq/g.

4. SPE Cartridge Specifications:

  • Cartridge Material: Choose a cartridge made from a material compatible with the sample and solvent. Common materials include polypropylene, polyethylene, glass, and stainless steel.
  • Bed Mass: The bed mass of the cartridge determines the amount of sample that can be processed in a single extraction. Choose an appropriate bed mass based on your sample size.
  • Cartridge Size and Format: Consider the physical dimensions and format of the cartridge, ensuring it fits well in your SPE instrument or manifold.
  • Particle Size of Packing Material: Smaller particles provide higher surface area, potentially leading to better extraction efficiency. However, very fine particles may increase backpressure.
  • Pore Size: Pore size affects the flow rate and retention of analytes. Smaller pores may provide better retention, but may also lead to slower flow rates.
  • Compatibility with Solvent: Ensure that the cartridge is compatible with the solvents you plan to use in the extraction process.
  • Specialty Features: Some cartridges come with additional features, such as frits or guard columns, which can enhance performance in specific applications.
  • Certifications and Compliance: Consider whether the cartridge meets any regulatory or quality standards required for your specific application.

Hawach provided Reversed Phase C18 SPE Cartridges, Ion-Exchange SCX SPE Cartridges, and Ion-Exchange SAX SPE Cartridges for your choose from.