Chromatography Column Size
2.Chromatographic Column (Rotation Type)
3.Chromatographic Column (Manual)
***Price List for whole above, inquire us to get
Description
Technical Parameters
Chromatography column size is a very important parameter in chromatographic analysis, which directly affects the effect and efficiency of chromatographic separation. The size of the column mainly includes the column length, inner diameter and the particle size and aperture of the packing (stationary phase).To judge whether its size is suitable, it is necessary to consider the sample characteristics, separation requirements, column performance and experimental verification results. Through scientific and reasonable selection and adjustment, you can find the most suitable size for your own experimental needs.
Column length refers to the length of the column, usually in millimeters (mm) as a unit, the common column length specifications are 250mm, 150mm, 100mm and 50mm. Long columns are usually used for sample analysis that is difficult to separate or requires high separation degree, such as the development of relevant substance analysis methods in the early stage of raw materials; The short column can realize fast and efficient detection, and is suitable for the dissolution degree/dissolution curve analysis method of preparations, biological sample analysis, etc.
The inner diameter refers to the inner diameter of the column, usually in millimeters (mm) as a unit, the laboratory commonly used column diameter specifications are 4.6mm, 2.1mm and so on. For complex samples requiring precise separation, small bore columns must be used; If there is a large concentration difference in the composition of the sample, in order to increase the sample capacity, it is recommended to use a larger diameter column.
In addition to column length and inner diameter, the particle size and aperture of the packing (stationary phase) are also important factors affecting the chromatographic separation effect.
 |
 |
 |
 |
Parameter
The influence of column length on bearing capacity
Relationship between column length and bearing capacity
The bearing capacity of the column refers to the amount of sample or sample concentration that it can handle and analyze. Column length is one of the important factors affecting the bearing capacity.
Increase of fixed phase area
As the column length increases, the number of fixed phase particles filled in the column increases, thereby increasing the contact area between the fixed phase and the mobile phase. This facilitates the adsorption and separation of the sample components on the stationary phase, thus improving the bearing capacity of the column.
Improved separation efficiency
The long column provides a longer path for the sample components to diffuse and adsorb between the stationary and mobile phases, thereby increasing the degree of separation between the components. The improved separation efficiency means that the column can more effectively separate samples of different components, thus increasing the load carrying capacity.
The impact of increasing column length on bearing capacity
While the increase in column length helps to improve the carrying capacity, it also has some negative effects:
Longer analysis time
As the column length increases, the residence time of the sample in the column will be correspondingly longer, resulting in an increase in the analysis time. This is a disadvantage for experiments that require fast analytical results.
Increased column pressure
Longer columns may increase column pressure because longer paths require more carrier gas to push the sample through. An increase in column pressure can negatively affect the stability and longevity of the chromatographic system.
Cost escalation
Long columns are usually more expensive than short columns because more materials and processes are required to prepare them. This increases the cost of the experiment, especially if a large number of columns are required.
Trade-offs in practical applications
In practical applications, there is a trade-off between column length and load-bearing capacity. Here are some suggestions:
Select column length based on sample complexity
For simple samples, shorter columns can be selected to reduce analysis time and cost. For complex samples, longer columns need to be selected to improve separation efficiency and load carrying capacity.
Consider the stability of the chromatographic system
When selecting a long column, it is necessary to ensure that the chromatographic system has sufficient stability and load carrying capacity to cope with the increased column pressure and mobile phase consumption.
Optimization of experimental conditions
By optimizing experimental conditions (such as carrier gas flow rate, temperature, etc.), the negative impact of the long column can be alleviated to a certain extent, and the bearing capacity and separation efficiency of the column can be improved.
Inside diameter
 |
 |
 |
The inner diameter of the column is a key parameter in chromatographic separation technology, which has significant effects on separation efficiency, column efficiency, retention value, pressure, carrier gas flow rate and column capacity. The following is a detailed discussion of the column diameter to help users better understand the importance of this parameter and its selection strategy in practical applications.
Definition and classification of column diameter
Column diameter refers to the diameter of the inside of the column, usually in millimeters (mm). According to the size of the inner diameter, the column can be divided into many types, including conventional analytical column, narrow diameter column, capillary column, semi-prepared column, laboratory prepared column and production prepared column. These different types of columns have different inner diameter ranges and are suitable for different analytical needs and sample types.
The influence of inner diameter on chromatographic separation
Separation efficiency and column efficiency: The inner diameter has a significant effect on the separation efficiency and column efficiency of the chromatographic column. The smaller the inner diameter, the higher the column efficiency, because the smaller inner diameter of the column can provide a smaller diffusion path, so that the sample components between the fixed phase and the mobile phase diffusion is more rapid and efficient. However, too small an inner diameter may lead to excessive column pressure, affecting the stability and life of the chromatographic system.
Retention value and separation degree: The inner diameter also affects the retention value and separation degree of the sample. The retention value of the sample in the column is usually reduced with a smaller inner diameter, because the column with a smaller inner diameter can pass through the sample faster, resulting in less adsorption time of the sample components on the stationary phase. However, by optimizing the experimental conditions (such as carrier gas flow rate, temperature, etc.), the retention value can be adjusted to a certain extent to meet specific analytical needs. At the same time, columns with small bore diameters typically have higher separations because smaller diffusion paths help better separate adjacent sample components.
Pressure and carrier gas flow rate: The inner diameter also has a significant effect on the column pressure and carrier gas flow rate. The smaller the bore diameter, the higher the stigma pressure required, because smaller channels require higher pressure to push the mobile phase through. At the same time, the flow rate of atmospheric pressure gas increases with the increase of column diameter. For methods or hardware that require high flow rates, columns with larger bore diameters are usually used; For methods or hardware that require low carrier gas flow rates, smaller bore columns are usually used.
Column capacity: The inner diameter also affects the column capacity of the column. The larger the inner diameter, the higher the column capacity is generally, because a larger inner diameter column can accommodate more stationary phase particles and sample components. This is very important for experiments dealing with large numbers of samples or high concentrations of samples. However, it should be noted that too large an inner diameter may result in a reduced separation efficiency because the diffusion path of the sample components over the stationary phase becomes longer.
The strategy of selecting the inner diameter of the column
When selecting the column diameter, the following factors need to be considered:
Sample complexity
The more complex the sample components, the more need to choose a smaller inner diameter column to improve the separation efficiency and separation degree. However, for simple samples or situations where rapid analysis is required, a column with a larger inner diameter can be selected to reduce analysis time and cost.
Analytical requirements
Select the appropriate column diameter according to the specific analytical requirements. For example, for analyses requiring high sensitivity and high resolution, columns with smaller inner diameters are usually selected; For cases where a large number of samples or a high concentration of samples need to be processed, a column with a larger inner diameter is selected.
Chromatographic system stability
When selecting a column with a small inner diameter, it is necessary to ensure that the chromatographic system has sufficient stability and load carrying capacity to cope with the possible increased column pressure and mobile phase consumption.
Cost considerations
Columns with different inner diameters have different prices. When choosing, it is necessary to consider the experimental cost and budget constraints to find the most cost-effective column specifications.
System pressure due to column length
Relationship between column length and system pressure
As the length of the column increases, so does the pressure on the system. This is because the liquid needs to overcome more resistance when passing through the column, including the friction resistance between the packing particles, the friction resistance between the liquid and the column wall. These resistance causes the system pressure to increase to ensure that the liquid can pass smoothly through the column. Therefore, in liquid chromatography system, column length is one of the important factors affecting the system pressure.
Other factors affecting the system pressure
In addition to column length, system pressure is affected by:
Packing particle size
The smaller the packing particle, the higher the system pressure. This is because the small particle filler provides a larger specific surface area and increases the interaction between the liquid and the filler, thereby increasing the system pressure.
Flow rate
As the flow rate increases, the system pressure increases. This is because the increased flow rate causes the liquid to move faster through the column, and the resistance to overcome increases accordingly.
Viscosity of the solution
The higher the viscosity of the solution, the higher the system pressure. High-viscosity solutions have greater resistance to flow through the column and therefore require higher system pressure to drive their flow.
Temperature
The effect of temperature on system pressure is inversely proportional, that is, when the temperature increases, the system pressure decreases. This is because the increase in temperature will reduce the viscosity of the solution and the coefficient of friction between the packing particles, thus reducing the flow resistance.
The importance of controlling system pressure
In liquid chromatography, it is very important to control system pressure. Excessive system pressure can lead to rupture or damage of the column, affecting the separation effect and the service life of the instrument. At the same time, excessive pressure may also increase the energy consumption and operating costs of the instrument. Therefore, in the design and operation of the liquid chromatography system, it is necessary to reasonably control the length of the column, the size of the packing particles, the flow rate, the solution viscosity and temperature, and other factors to ensure that the system pressure is in a suitable range.
Hot Tags: chromatography column size, China chromatography column size manufacturers, suppliers, factory, Rotovap Machine, Rotary Evaporators, Hydrothermal Synthesis Reactor, 16 Station Tablet Compression Machine, Zp9 Rotary Tablet Press, 20l Rotary Evaporator
Send Inquiry
