What is GPC system?
The full name of the
GPC system is
gel permeation chromatography system. It is a relatively traditional separation technique, based on the principle of gel permeation chromatography to separate and collect complex samples according to the size of the molecular volume, which can effectively remove the large molecular matrix and small molecules in the sample, improve the sensitivity and accuracy of subsequent analysis, and extend the service life of analytical instruments. It is widely used in the fields of environmental testing, agricultural products testing, food testing and life science.
Application of GPC system
As a scientific equipment, GPC system in the analysis of pesticide residues and semi-volatile organic compounds in various types of food, agricultural products and aquatic products, in organic sample extracts generally contain large molecules, if these substances are not removed, it will lead to a reduction in the separation efficiency of the column, shorten the life of the injection port and column, and then affect the data analysis results. Therefore, effective cleanup pretreatment is necessary before sample analysis of pesticide residues and semi-volatile organic compounds. The traditional pretreatment process is time-consuming and solvent consumption is high, so the large-scale application of gel cleanup system is an inevitable trend.
GPC system working principle
Gel permeation chromatography system working principle, on which the gel purification system works, separates and collects complex samples according to the size of the solute molecules. The column packing gel has pores of different sizes, and when component molecules of different sizes enter the gel with the mobile phase, the smaller the molecules are the deeper they enter the micropores and the longer they are retained in the gel, so they can be eluted in order of molecular size. Large molecules are eluted first and small molecules are eluted later. The detector detects the signal and the component collector collects the eluate containing the target components.
Advantages of using GPC system
a. GPC system is high purification efficiency, saves a lot of time and solvent, improves work efficiency, fills without manual participation, and reduces the harm of organic solvent to the experimenter.
b. Recommend to use stainless steel purification column, strong pressure resistance, safe and reliable.
c. Adopt the medium-pressure homogenization method for mechanical loading of columns, the purification column is formed once, with good batch reproducibility, which is convenient for method fixation.
d. Less interference by external factors, universal interface, easy to use.
e. A built-in filter effectively reduces the interference of impurities to the johkasou column and can be replaced to extend the service life.
f. A gel purification system with multiple specifications of stainless steel purification column and glass purification column is available, and the glass purification column has a spiral mouth design, which is convenient to adjust the column length. It can eliminate the problem of the traditional glass johkasou column collapsing under pressure and the need to adjust the column length.
Structure of GPC system
GPC system is composed of purification host and liquid workstation, with integrated design, compact and coordinated layout, which can automate sample feeding, separation and purification, target component collection series operations, and control software to perform data acquisition, storage, and management functions. The appearance of equipment has a working status indicator, which clearly shows the working status of each step and can be seen from a distance. It can be upgraded to be used online with an automatic quantitative concentration system, single-channel or multi-channel automatic solid phase extraction system.
Functional characteristics of GPC system.
High precision double plunger infusion pump
The performance index of the pump reflects the overall performance of GPC system and is related to the service life of the whole system. The good performance of the double plunger tandem infusion pump can effectively ensure the stability and reliability of the system, which plays an important role in the reproducibility of the recovery rate and avoids the unstable flow and pressure of the cheap single plunger infusion pump. It is also equipped with a diaphragm damper to further reduce mobile phase pulsation.
Automatic liquid processor
Automatic liquid processor with automatic sample injection and automatic collection function. Large sample capacity, stable performance, support a variety of sample bottles, XYZ three-dimensional movement mode, can carry four sample trays, any combination to set the injection and collection position, a variety of tray combinations, and a variety of sample bottle specifications to meet experimental needs; septum puncture function and injection needle following the liquid surface function, effectively reduce sample cross-contamination and volatilization, the injection needle using immersion cleaning, internal and external wall cleaning to a large extent Reduce cross-contamination. The mechanical arm is not disturbed by external forces, fully automatic calibration position; optional sample tray cooling device to reduce sample volatilization.
Variable wavelength UV detector
Gel permeation chromatography systems can be provided with different wavelength UV detectors, which act as the eyes of the whole system, playing the role of detecting the spectrum and mastering the experimental dynamics in real-time. A variable wavelength UV detector is standard and can be selected to detect the absorption wavelength of the substance to be measured, improving sample resolution and detection accuracy.
Manifold control system
The valve system is a key part of the smooth flow and control of the whole equipment. The whole valve system has the advantages of no adsorption of samples, no local interference, strong pressure resistance, high precision, and long service life.
Types of gels in GPC system
Gels are the core of the GPC system and are the basis for the separation of components. Many gels have been developed and used, with different preparation processes, techniques, and conditions of use.
1. The source of gel material can be divided into organic and inorganic gels.
2. The preparation method can be divided into uniform, semi-uniform, and non-uniform.
3. According to the nature of the strength of the gel, it can be divided into a soft gel, semi-hard gel, and hard gel.
4. Hydrophilic, lipophilic, and amphoteric gels can be classified according to the range of solvents used. Hydrophilic gels are mainly used for the separation and analysis of proteins and enzymes in biochemical research, while lipophilic gels are used for the separation and analysis of compounds in synthetic polymer materials and organic systems. The selection and use of gels with different properties and different pore sizes determine the effectiveness of the separation and purification, and the type of gel chosen can usually be determined by the type of sample matrix and the molecular size of the components to be separated.
What conditions need to be satisfied for GPC system?
1.
GPC system should be able to detect very low concentration of solute content with high sensitivity.
2. The GPC system is insensitive to changes in flow rate, pulsation and temperature, and is capable of continuous automatic detection of chromatographic effluents with good stability to ensure long term use.
3. In order to improve detection sensitivity and prevent peak broadening, the GPC detector must have the smallest possible cell volume and a certain pressure tolerance.
4. The noise and drift level of the GPC system should be low.
5. The GPC system should be able to give quantitative response values for the concentration of the sample, and the response value should have a wide linear dynamic range with the concentration.
6. The GPC detector must be non-destructive for the sample being analyzed.
7. The response time should be fast so that the outflow time or volume of the peak can be recorded quickly.
How to use GPC system?
Here's how to use the gel permeation chromatography system system.
Mobile phase
Mobile phase purity: It is recommended to use chromatographic pure mobile phase or above, such as ethyl acetate: cyclohexane = 1:1 or methylene chloride.
Before using GPC system, please make sure to configure the corresponding mobile phase according to the label specification (ethyl acetate: cyclohexane = 1:1 or dichloromethane) on the gel clean-up column, and the mobile phase should meet the requirements of the experimental process. The mobile phase should only be ethyl acetate:cyclohexane (1:1), especially not dichloromethane, otherwise it will affect the expansion coefficient of the packing of the gel column, and thus the column will not be used effectively. Need to use 0.45 micron filter membrane filtration and ultrasonic degasification mix uniformly.
The amount of mobile phase: Since the flow rate in the method is 5mL/min, if the number of experimental samples is large, the mobile phase should be prepared in sufficient amount at one time to avoid adding it to the reagent bottle in the middle. Otherwise, it is easy to generate bubbles, resulting in unstable baseline.
Selection of sample solvent
When using GPC, please pay attention to the effect of the sample solvent on the gel column, i.e., when choosing the sample solvent, you should select a solvent that matches the polarity of the mobile phase and try to use the mobile phase as the sample solvent.
The amount of mobile phase: Since the flow rate in the method is 5mL/min, if the number of experimental samples is large, the mobile phase should be prepared in sufficient amount at one time to avoid adding it to the reagent bottle in the middle. Otherwise, it is easy to generate bubbles, resulting in unstable baseline.
Infusion pump pressure is high
If you find that the infusion pump pressure on the control panel becomes high or the alarm stops the pump, please remove the emptying filter holder of the GPC instrument and clean it with mobile phase ultrasound for 10~20min before installing it for use.
How to maintain GPC system?
Routine maintenance of GPC system is as follows.
Cleaning of GPC pipeline
If you use the GPC instrument for darker samples such as tea or when the recovery rate decreases, please remove the gel cleanup column every half month, replace the column with a stainless steel two-way to connect the line, then change the mobile phase to methanol: acetone (1:1), rinse the line for one hour, then switch back to the mobile phase and rinse for twenty minutes, then install the gel column and experiment again.
Cleaning of the protection column
When the recovery of GPC decreases, rinse the column with methanol: acetone (1:1) at a low flow rate in reverse for twenty minutes if a protected column is available.
Maintenance of automatic liquid processor
Please do not move or change the sample holder on the sample tray during use, because the position has been adjusted at the time of installation. Moving or changing the sample holder on the sample tray will probably result in accidents such as breaking the sample injection needle. After the experiment is finished, please do some dustproof measures as much as possible to prolong the life of its use.
How to buy GPC system?
ANTITECK provide lab equipment, lab consumable, manufacturing equipment in life sciences sector. If you are interested in our
GPC system or have any questions, please write an e-mail to
[email protected], we will reply to you as soon as possible.
