Introduction to Stainless Steel Tubes for Chromatography Columns

characteristic

Strong corrosion resistance: It can resist the corrosion of various chemical substances, such as in liquid chromatography, it can withstand the corrosion of various mobile phase solvents, buffer solutions, etc., ensuring the structural stability of the chromatographic column during long-term use, and is not easily damaged by chemical substances, thus extending its service life.

Good high-temperature stability: In the high-temperature environment of gas chromatography analysis, stainless steel capillary columns can maintain stable performance without deformation, damage or performance degradation due to high temperature, ensuring the accuracy and reproducibility of chromatographic analysis under high temperature conditions.

High mechanical strength: Stainless steel material has high hardness and strength, allowing the chromatography column to withstand certain pressure. In applications such as high-pressure liquid chromatography (HPLC), it can withstand the high pressure of the mobile phase and is not easily broken or deformed, ensuring the safe operation of the system.

High precision: With advanced manufacturing technology, high dimensional accuracy, and good uniformity of inner diameter, the flow state of the sample inside the tube can be ensured to be stable, providing reliable separation effect for chromatographic analysis and helping to improve the accuracy and repeatability of the analysis.

High inner wall smoothness: After precision polishing or electropolishing treatment, the inner surface smoothness can reach 0.1 μ m or even higher, which can greatly reduce the adsorption and retention of the sample by the pipe wall, reduce the "pipe wall effect", and enable the sample to be evenly distributed and flow rapidly in the column, improving column efficiency.

Common materials

316L stainless steel: It has excellent corrosion resistance, especially good resistance to media containing chloride ions, and can maintain stability in various chemical environments. At the same time, it has good processing performance and is easy to make various specifications of chromatographic columns, suitable for most conventional chromatographic analysis applications.

316L stainless steel: It belongs to the medical implant grade 316L stainless steel, with higher purity, lower inclusion content, and superior corrosion resistance and biocompatibility. Widely used in chromatographic analysis in fields such as biochemistry and pharmaceuticals, it can avoid interference from impurities in stainless steel tubes on biological samples.

manufacturing process

Cold rolling and cold drawing: By processing stainless steel pipes through cold rolling and cold drawing processes, the cross-sectional area can be reduced to achieve the required dimensional accuracy and surface quality, while improving the strength and hardness of the pipes.

Polishing treatment: including mechanical polishing, chemical polishing, and electropolishing, among which electropolishing is a commonly used process that can achieve extremely high smoothness on the inner surface of stainless steel pipes, remove micro defects and impurities on the surface, reduce surface roughness, and improve column efficiency.

Passivation treatment: Stainless steel pipes are usually passivated using solutions such as nitric acid, forming a dense passivation film on their surface to enhance their corrosion resistance and prevent rusting or corrosion during use.

Specification and size

Inner diameter: The inner diameter of conventional analytical columns is usually between 1.00mm and 4.6mm, such as 2.1mm, 3.0mm, 4.0mm, 4.6mm, etc., suitable for different types of chromatographic analysis instruments and analysis requirements. The inner diameter of a semi prepared column is generally 6mm-20mm, while the inner diameter of a prepared column can be larger for processing larger volumes of samples for material separation and preparation.

Length: The length range of chromatographic column tubes is wide, commonly including 30mm, 50mm, 75mm, 100mm, 150mm, 200mm, 250mm, and even longer. Shorter columns are suitable for rapid analysis or situations where separation requirements are not particularly high, while longer columns can provide higher separation for fine separation of complex samples.

application area 

Liquid chromatography: In high-performance liquid chromatography (HPLC) and ultra high performance liquid chromatography (UPLC), stainless steel tubes are commonly used as chromatographic column materials, which can be used to separate and analyze various organic compounds, biomolecules, drug components, etc., such as in the pharmaceutical industry for drug quality control and impurity analysis, and in the food industry for detecting additives, pollutants, etc. in food.

Gas chromatography: Stainless steel capillary chromatography columns are widely used in gas chromatography analysis, and can be used to separate and detect various volatile organic compounds, gas components, etc., such as detecting pollutants in the air in environmental monitoring and analyzing the composition of petroleum products in the petrochemical industry.