Liquid chromatography column is made of column, Pressure cap, cutting sleeve(sealing ring), frit cap（filter disc), connector, thread and so on. There are many materials for column tubes, such as polymer, glass, stainless steel and so on. The highly recomment is stainless steel material. Because stainless steel have advantage of anti-pressure, anti-corrossion and high hardness. Compared with glass material and other materials, it is not easy to broken. But we can use thick wall glass or quartz tube when the pressure is not high than 70Kg/cm2. The inner wall of the liquid chromatography column is required to have a very high finish. The inner wall of the stainless steel column will be polished several times, which is to improve the column efficiency and reduce the wall effect. UHPLCS 0.1um inner surface roughness HPLC guard column tube allows rapid analysis while maintaining high column efficiency.It has advantage of long service time, reduced frequent column replacement brought about by the new method verification, condition exploration and other work and lower the use-cost with excellent selectivity and speration ability.
In addition to polishing, coating fluoroplastics in inner wall of stainless steel column also can improve the degree of finish of inner wall. The column ends are equipped with a sieve plate in the stigma, it usually made of stainless steel and peek. Column sieve plate matched with chromatographic column also available according requirment.
The inner diameter of the column is generally determined according to the length of the column, the particle size of the filler and the reduced flow rate, in order to avoid the wall effect.
What is the selection principle of colunmn lenght and inner diameter? The longer the column, more high total column efficiency(The N is more larger) and the analyze time is more long. 250-300mm is the general column lenght. More than half of the work in the laboratory is done with columns of this size column, generally used to separate medium to complex mixtures of 10 to 50 components. 500—600mm is apply in higher resolution and generally used to separate medium to complex mixtures of 10 to 50 components.
Inner diameter:Column efficiency is inversely proportional to the square of the column radius.The higher the inner diameter, the higher the column efficiency, but the larger the inner diameter, the higher the column capacity, the more allowed injection volume.When the inlet volume exceeds the column capacity, true equilibrium cannot be established in each theoretical plate in the column, which will cause chromatographic peak distortion, lower column resolution, and poor reproducibility. Therefore, for complex samples that require accurate separation, a small inner diameter column must be used.On the other hand, if there are compounds with very different concentrations in the sample, a column with a large inner diameter must be used in order to increase the sample capacity. The inner diameter of a common column currently used in laboratories is generally 4.6mm.
Analyze large-molecular-weight compounds choose large-pore chromatographic columns；For high pH or basic compounds, it is necessary to choose high-end-capped or special-end-capped chromatographic columns to improve peak shape and extend the service life of the chromatographic column. We have 2.1, 3.0,4.6 and 10mm inner diameter liquid chromatography column for your reference.
The selection principle for column length and inner diameter of Liquid chromatography columnare above for your reference. Shenzhen UHPLCS Scinentific instruments Co.,Ltd is a high-tech manufacturer focused on R&D and manufacturing od high quality chromatography cosumables. We have rich production experience and strong manufacturing technology capabilities in long service life, guard column with high purification capacity, 0.1um inner surface roughness HPLC guard column tube.
Our strategic partners are all over the chemical, pharmaceutical, biological, medical, food, materials, environmental protection, agriculture, inspection, scientific research and other industries. Our products have exported to Europe, American, Russia, Canada,Australia, Southeast Asia and other developed economies of pharmaceutical and chemical science that have high quality requirements for their products in this industry. We look forward to working with customers to establish closer strategic relations of cooperation, hand in hand to create a better future!
Post time: Jan-22-2021
