HPLC Columns Packing
The components of the liquid chromatography column are composed of an empty column, joint, column tube, and other parts. The selection of columns is based on the type of packing. The separation of the liquid chromatography column is carried out between the filler and the mobile phase. The classification of the column depends on the type of HPLC column packing, and what type of packing is called the column.
HPLC column packing refers to the stationary phase material packed inside high-performance liquid chromatography columns and is a critical factor determining separation efficiency, resolution, reproducibility, and column lifetime. Our HPLC column packing materials are manufactured under strict quality control to deliver consistent particle morphology, uniform surface chemistry, and reliable batch-to-batch performance.
Normal-phase column
Mostly silica gel HPLC column packing. According to its appearance, it can be divided into two types: amorphous and spherical, and its particle diameter is in the range of 3-10 μm. Another type of normal phase filler is silica gel surface bonding – a functional group such as CN, -NH2, so-called bonded phase silica gel. HPLC normal phase chromatography column has CN HPLC column, NH2 HPLC Columns, etc.
Reversed-phase column
A non-polar filler mainly based on silica gel has an octadecyl functional group (ODS) bonded to its surface. There are also amorphous and spherical types. Other commonly used reversed-phase fillers are bonded to C8, C4, C2, phenyl, etc., and the particle size is between 3 and 10 μm. HPLC reversed-phase chromatography columns include Reversed Phase C4 HPLC Columns, Phenyl HPLC Columns, C8 Low pH HPLC Columns, etc.
Development Trend of HPLC Packing Technology
High-performance liquid chromatography (HPLC) is a modern separation and analysis method. Since the 1960s, as an analytical technique, HPLC has been widely used in life science, environmental science, pharmaceutical analysis, and other fields. Among them, chromatographic packing is the core of chromatographic technology. It is not only the foundation of the chromatographic method but also an important consumable. As the carrier of chromatographic packing, the chromatographic column is well known as the “heart” of chromatography. High-performance liquid chromatography packing has always been a rich, dynamic, and creative research direction in chromatographic research.
Because of their excellent chromatographic performance, silica gel-based chromatographic fillers are widely used as liquid chromatography fillers, especially for the separation and analysis of small organic molecules. Silica gel-based chromatographic fillers occupy the majority of the market share. In recent years, exciting developments in this field have been based on the development of rapid liquid-phase technology in two directions.
Super HPLC packing technology
Since Waters launched the UPLC instrument in 2004, ultra-high performance liquid chromatography (UHPC) technology has been widely used for its advantages of high speed, high separation, and high sensitivity.
The core of this technology is based on the chromatographic packing of 2μm small particle-size silica gel. When the packing particle is less than 2μm, not only is the column efficiency obviously improved, but also the separation efficiency does not decrease with the increase of flow rate. The separation velocity and peak capacity can be extended to a new limit by using a high flow rate, but the column pressure also increases significantly. An ultra-high performance liquid chromatography (UHPC) system with higher pressure is needed for small-sized fillers, and the production process of chromatographic columns is also required to meet higher requirements.
Currently, in addition to the well-known international chromatographic instrument and column companies (such as Waters, Agilent, and Phenomenex), which also produce UHPLC columns, Chinese chromatographic column manufacturers have introduced similar products. Although UHPLC instruments are still the monopoly of internationally famous brands, Chinese UHPLC columns can replace most brands.
Core-shell chromatography packing
Core-shell packing is a new type of chromatographic packing developed by Jack Kirkland in 2006. It is prepared by melting the porous silicon shell onto the solid silicon core surface. These porous “halo” particles have a very narrow particle size distribution and a diffusion path, which can reduce both axial and vertical diffusion. This allows the use of shorter chromatographic columns and higher flow rates to achieve rapid and high-resolution separations.
Moreover, the back pressure produced by the core-shell column is lower than that of the UHPLC column. Low back pressure can reduce the pressure of the instrument, which makes it possible to achieve the separation effect of ultra-high performance liquid chromatography on conventional liquid chromatography. However, the core-shell chromatographic column is not suitable for large-scale preparation of liquid chromatography because of its high requirement for the dead volume outside the column, and its capacity is smaller than that of the full-porous packing.
