What are the HPLC Column Classifications?
The HPLC column generally consists of a column tube, a pressure cap, a ferrule (seal ring), a sieve plate (filter), a joint, a screw, and the like. The column is a column tube with a stationary phase for separating the mixture. It is mostly made of metal or glass. It has the shape of a straight tube, a coil, a U-tube, etc., and is widely used in many fields.
HPLC column classification
In general, depending on the nature of the sample, which LC method is used, and then select different types of columns. That is, different types of columns represent different chromatographic methods.
The difference between different types of HPLC columns is the difference in column structure, column packing, and column size.
HPLC columns are available in different sizes (length and inner diameter), sub-preparative, routine analytical and micro. The hardware of different types of columns is also different (including joints, columns, etc.), as well as radial pressurized columns and jacketed heating columns.
The size of different liquid chromatography methods can be selected according to requirements, and the common analysis is 3 to 30 cm long and the inner diameter is 4 to 8 mm. A column of 20 cm long and 4.6 mm inner diameter is commonly used. The preparation column has an inner diameter of generally 8 mm and a length of 25 cm. The microcolumn has an inner diameter of l to 3 mm and a length of 10 to 20 cm. The effect of different filler analyses may vary, due to differences in the production process. The same type of filler produced by the same manufacturer may vary from batch to batch, and this difference may start from the substrate (surface area, impurities, special treatment), as well as bonded chemicals (monochloro or trichlorosilane reactants). Fillers produced by different manufacturers will also vary greatly depending on the patented technology (pretreatment, bonding process, filling technology). Due to various differences, it can only be assumed that the columns of the same batch number have substantially the same properties.
Most column packing matrices use porous silica particles, usually spherical and amorphous, with different particle sizes, pore sizes and surface areas. Porous polymer microparticles are also suitable for reversed phase chromatography. The polymer column has a wide mobile phase range and the mobile phase pH can range from 1 to 13. The silica matrix pH can only be between 2.5 and 7. Obviously, the polymer column is better, but it is still dominated by silica-based columns. In principle, polymer columns can overcome some of the deficiencies of silica matrix columns, but a large number of experiments are needed to confirm the overall superiority of polymer matrix fillers.