Size Exclusion Chromatography Technology

Size Exclusion Chromatography (SEC) is a chromatography technology method in which molecules are separated in order of Size. Molecules with large volumes cannot penetrate gel pores and therefore are excluded. Small molecules can be completely permeable and finally eluted out. In this way, the sample molecules are obstructed according to their molecular size and flow out of the column. It is widely used to analyze the distribution of relative molecular mass of macromolecular substances.

Fig.1 Schematic diagram of size exclusion chromatography principle.

• Stationary phase pre-treatment
  The stationary phase material is first soaked overnight in a solvent to be used as the mobile phase. This allows the stationary phase material to absorb the solvent and become soft, flexible gel beads. The inner diameter of the beads is different, and pores of different sizes are formed inside these beads.
• Column packing
  The porous beads are placed in a glass column, and under the action of gravity, they have time to settle and then form a close packing.
• Sample loading
  The sample slurry is prepared by adding the mobile phase to the analyte mixture. Therefore, this mixture is loaded onto the stationary phase-packed column. Another layer of the mobile phase is then introduced on top of it and allowed to move down the column, carrying analyte components.
• Analyte separation
  Molecules larger than the pore size are easily eluted out of the column, the smallest will stay for a long time and eventually be eluted out of the column. The signal is sent to the detector, which produces a chromatographic response.

• Predicted separation: based on molecular size.
• High efficiency: no sample loss and reaction occur in the separation process.
• Long column life: the activity of the column rarely disappears.
• Obtain molecular structure information: the retention time depends on the molecular size.
• Easy detection: short and well-defined separation times and narrow bands.

• Separation of macromolecular substances: tissue extracts, peptides, proteins, and nucleic acids.
• Measurement of relative molecular mass distribution: identification of polymers and research of polymer polymerization mechanism, polymerization process, conditions, etc.

Chromatography Columns

Chromatography is an analytical technique that separates components in a mixture. Chromatographic columns are part of the instrumentation that is used in chromatography. Columns play a central role in the performance of chromatographic process. Well-packed columns with consistent performance in the whole design space of a process will deliver consistent product recovery and separation from contaminants.

Chromatography Fraction Collector

The fraction collector is typically a rotating rack that can be filled with test tubes or similar containers. If the chromatographic separation is not for pure chromatographic analysis, but for other spectral identification, or to obtain small-scale preparation of a small number of test samples, fraction collection is necessary, and fraction collector collection is ideal and accurate in operation.

Chromatography Syringes

Syringes and syringe accessories for use with autosamplers, injectors, mass spectrometers, and other chromatography systems. We understand that choosing the right chromatography syringes can be critical to getting accurate results. That’s why you’ll find a large selection of chromatography syringes, including reusable glass, all-polypropylene, 3-part disposable syringes and more.

Pipettes and Pipette Tips

Pipette is a measuring tool that moves liquid from the original container to another container within a certain range. It is widely used in clinical diagnostic laboratories, biotechnology laboratories, pharmaceutical and chemical laboratories, environmental laboratories, and food laboratories. We provide a variety of pipettes for you to choose to use in a variety of experimental research.

Chromatography Detector

A chromatography detector is a device used in gas chromatography (GC) or liquid chromatography (LC) to detect components of the mixture being eluted off the chromatography column. The function of the detector is to convert the change of the sample composition and content in the chromatographic column effluent into a signal that can be detected.

STEMart provides you with a variety of size exclusion chromatography technology equipment to help you quickly and efficiently separate and analyze to meet your various R&D and application needs. If you have any questions or requirements for chromatography equipment, please feel free to contact us.