SPE and the SPE Cartridges

As one of the useful sample preparation techniques, solid phase extraction can prevent many problems, such as incomplete phase separations, recoveries with poor quantity, waste of expensive fragile glassware, and extra disposal of organic solvents, which you may occur if you use the liquid/liquid extraction.

On the other hand, SPE takes quantitative extractions that are easy to perform with high speed and automation. So it is a more efficient way of extraction than liquid/liquid. To reduce solvent use and lab time, it is often used when we prepare liquid samples, extract semivolatile or nonvolatile analytes, and solids pre-extracted from solvents.

With the purity of the advanced extract, SPE is perfect for super-complex analyzes. The right choice of SPE cartridges and sorbents will help you achieve a better result. Suitable with many different sorbents, SPE cartridges coincide with the filling materials of HPLC columns, such as reversed phase, normal phase, ion exchange, and the “mixed mode” materials.

Solid Phase Extraction (SPE) is a physical extraction process including a liquid phase and a solid phase, which can be regarded as a simple chromatographic process. This technology develops rapidly and is widely used in the environment, pharmacy, clinical medicine, food, and other fields.

The basic principle of SPE cartridges

1. Distribution of samples between the solid phase (adsorbent) and the liquid phase (solvent).
2. The mechanism of retention or elution depends on the active groups on the surface of the analyte and the adsorbent, as well as the molecular forces between the analyte and the liquid phase.

Features of SPE cartridges

1. Rapid separation, purification, and concentration;
2. Can selectively adsorb interfering impurities;
3. High purity and concentrated separation can be obtained;
4. Improved detection sensitivity.

Advantages of SPE cartridges

1. High recovery rate and enrichment multiple;
2. Reduce environmental pollution;
3. No phase separation operation process, easy to collect analytes;
4. Simple operation, fast, low cost.

The specifications of SPE cartridges

Volume: 0.01 ml – 200 ml
Particle Size: 5 µm – 250 µm
Pore Size: 40 Å – 450 Å

Organic solvents of SPE cartridges

N-ethane, cyclopentane, carbon tetrachloride, toluene, benzene, anhydrous ether, chloroform, dichloromethane, tetrahydrofuran, ethyl acetate, acetone, acetonitrile, isopropanol, methanol, water, acetic acid

The basic device of SPE cartridges

Solid phase extraction column and solid phase extraction filtration device. The column is the core of the solid phase extraction unit. It resembles a syringe.
SPE can be used for all types of samples, but liquid samples are the easiest to handle.

Separation modes of SPE cartridges

1. Reversed-phase, such as Reversed Phase C18 SPE Cartridge, Reversed Phase C8 SPE Cartridge, C4, C2, phenyl and so on;
2. Normal phase, such as silica gel bonding -NH2, -CN, Normal Phase Diol SPE Cartridge, and so on;
3. Ion exchange for extraction and separation of charged analytes, such as Ion-Exchange PRS SPE Cartridges, Ion-Exchange PSA SPE Cartridge, and Ion-Exchange SCX SPE Cartridge;
4. Mixed Mode, such as Mixed Mode Octyl(C8)/SCX SPE Cartridges.

Application of SPE cartridges

1. Detection and analysis of serum, body fluids, and liquid drug components in medicine;
2. Detection of pesticide residues in vegetables and fruits in food;
3. Detection and analysis of organic matter in atmospheric surface water and soil in the environment.

Solid phase extraction (SPE) is to use adsorbent to absorb the target compound in the liquid sample, separates it from the matrix and interfering compound of the sample, and then elution with eluent to achieve the purpose of separation or enrichment of the target compound.

SPE generally includes four procedures (adsorbent activation, sampling, leaching, and elution). A suitable adsorbent can adsorb first target compounds and clear of other interfering compounds.