Creative BioMart Chromatography provides custom surface coating services on chromatographic columns, capillary columns, micro-channels, nanoparticles, or other substances. We have decades of expertise in surface coating technology, with excellent thickness control. The polarity and functionality of the coating can be easily designed to meet various applications and reduce potential chemisorption.
Why Surface Coating Is Needed?
The normal alkane mixture (C5-C12) prepared in equal proportions was used as the analytical component. And the effect of coating on component separation was identified by the GC system. Under the same conditions, the chromatogram of the uncoated column has only a single peak (Figure 1a), while the chromatogram of the coated column shows that many alkanes have been substantially separated (Figure 1b).
Fig. 1 Column separation performance verification. (a) Uncoated column, (b) column coated with the stationary phase. (Han B.Q., et al, 2019)
Coating the silicon surface with suitable materials before the deposition of the ionic liquid can effectively improve the separation efficiency of microcolumn. For example, a thin layer of aluminum oxide is deposited on the surface of the channel through the atomic deposition. After alumina deposition, the channels were coated with an RTIL. At the optimal flow rate, the separation efficiency of the aluminum pretreatment column was 2.1 times higher than that of the column without the alumina layer. (Regmi B.P., et al, 2018) In addition, tiny scratches or even 1 μm pit on the surface of fused-silica can cause column failure almost immediately. The use of polyimide coatings can protect the outer fused-silica surface from abrasive damage and subsequent breakage, producing much more rugged capillary columns. A lack of basic understanding of the appropriate polyimide application and curing process can lead to clumping, particulate inclusions, and blisters in the finished coating, which can reduce the strength of silica capillary. Therefore, you need professional coating services to ensure the quality of your products.
Coating Methods
Dynamic coating
By the flow of a nonreactive gas, the plug of the stationary phase in the appropriate solvent is pushed through the column. The thickness of the stationary phase film can be controlled by the plug velocity and the concentration of the stationary phase in the solvent. When the plug is removed from the end of the column, the excess solvent evaporates in a continuous airflow, leaving a stationary phase film on the wall of the fused-silica tube. There are many variants derived from this method.
Static coating
The entire column is filled with a stationary phase solution, one end is sealed, and a vacuum is applied to the open end. The front of the liquid-vapor transition point is propagated away from the low-pressure end of the column. Once the solvent is completely pumped out, the coating is complete. And the stationary phase coating is more uniform than the dynamic coating.
The Benefits
- Better peak resolution, improve test consistency.
- Less sample carryover and contamination.
- Faster response, Higher efficiency.
- Assuring consistent column performance.
Creative BioMart Chromatography is committed to solving all your problems with the surface coating. We provide the best surface coating services in the world in an efficient and high-quality manner. Our customers have direct access to our experts and give timely feedback to any online inquiries. If you are interested in our services, please contact us.
How to Place an Order
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References:
- Han B.Q., et al. (2019). A semi-packed micro GC column for separation of the NAFLD exhaled breath VOCs. Surface & Coatings Technology. 363, 322–329.
- Regmi B.P., et al. (2018). Ionic liquid-coated alumina-pretreated micro gas chromatography columns for high-efficient separations. Journal of Chromatography A. 1566, 124–134.
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