Combined with sample pretreatment techniques, the high resolution and sensitivity achieved by HPLC make it possible to separate and simultaneously determine substances with similar properties, enabling the separation of trace components in complex phases. With the development of stationary phases, it is possible to achieve their separation under conditions that fully maintain the activity of biochemical substances.

The system of a liquid chromatography manufacturer consists of several parts, including a reservoir, pump, injector, chromatography column, detector, recorder, etc. The mobile phase in the reservoir is pumped into the system by a high-pressure pump, and the sample solution enters the mobile phase through the injector and is loaded into the chromatographic column (stationary phase) by the mobile phase. Due to the different distribution coefficients of each component in the sample solution in the two phases, when they move relative to each other in the two phases, they undergo repeated adsorption desorption distribution processes, resulting in significant differences in their movement speed. They are separated into individual components and flow out of the column in sequence. When passing through the detector, the sample concentration is converted into an electrical signal and transmitted to the recorder, and the data is printed in the form of a spectrum.

Understanding of Liquid Chromatography Manufacturers

The distribution coefficient is related to the thermodynamic properties of the components, mobile phase, and stationary phase, as well as temperature and pressure. In different chromatographic separation mechanisms, K has different concepts: adsorption chromatography is the adsorption coefficient, ion exchange chromatography is the selectivity coefficient (or exchange coefficient), and gel chromatography is the permeation parameter. But in general, it can be represented by the allocation coefficient.

When the conditions (mobile phase, stationary phase, temperature, pressure, etc.) are constant and the sample concentration is very low (Cs, Cm are very small), K depends only on the properties of the components and is independent of the concentration. This is just the ideal chromatographic condition, under which the obtained chromatographic peak is a normal peak; In many cases, as the concentration increases, K decreases, and the chromatographic peak becomes a tailing peak; Sometimes, as the solute concentration increases, K also increases, and the chromatographic peak becomes a forward peak. Therefore, only by minimizing the injection volume as much as possible, reducing the concentration of components in the column, and keeping K constant, can normal peaks be obtained.