Research and development of radial high pressure cylinder

Zhao Shiming, Liaocheng Wanhe Industrial Manufacturing Co., Ltd The results show that the rapid separation of sensitive compounds and natural products needs a large area TLC model, and the radial high pressure cylinder column can meet this requirement In this paper, the basic structure and using method of radial high pressure cylinder are described It provides a new way for the chemists who are committed to bioengineering and plant extraction and separation Key words: radial high pressure cylinder column; sensitive compounds; natural products; rapid separation; large area thin layer chromatography I overview chromatography technology is a technical system which can separate each component in the mixture through different retention time caused by different forces between the two phases It can be said that the chromatographic process is a separation process High performance liquid chromatography (HPLC) is a kind of separation and analysis technology, which can quickly separate different components in various samples, and then carry out qualitative and quantitative analysis one by one The application of HPLC in separation and purification technology has been greatly developed in the past ten years Compared with the traditional separation and purification methods, its rapid and automatic operation has attracted the attention of pharmaceutical industry HPLC is becoming the mainstream of drug separation and purification technology Drugs have a great relationship with human health Because of the influence of purity, many drugs can not give full play to their efficacy and even produce toxic and side effects Some need to do a variety of tests before use, which brings a lot of trouble Racemic drugs are one of the typical examples It is composed of two optical isomers, L-isomer and R-isomer Different isomers have different pharmacology and curative effect In the past, because of the limitation of separation and purification ability, racemates were often sold in the market FDA (food and Drug Administration) and many western countries have made the decision to prohibit the sale of racemic drugs on the market It is necessary to separate it into a single left-handed or right-handed body to be listed as a product Therefore, higher requirements for separation and purification of drug products are put forward At present, liquid chromatography is an effective method for the separation and purification of multi-component complex systems HPLC method is also a good choice for the separation and purification of Zui Liquid chromatography is widely used It can be used to analyze thermal unstable compounds, nonvolatile compounds with high boiling point and ionic compounds which are difficult to analyze by gas chromatography In general, the molecular weight of the analytical object of gas chromatography is not more than a few hundred, while liquid chromatography can deal with various types of compounds with molecular weight more than a few hundred Even for polymers with molecular weight as high as tens of thousands or hundreds of thousands, liquid chromatography can also complete the analysis work Of course, for small molecular weight nonpolar compounds or gases, liquid chromatography is unable to analyze It is estimated that 25% of all known organic compounds can be analyzed by gas chromatography, and the rest are mainly by liquid chromatography The preparation of liquid chromatography is based on the amplification design of liquid analysis chromatography, which is to change the process of finding a certain substance in analysis chromatography into extraction or separation of a certain substance It is an effective preparative separation technology of Zui in separation science, and also an indispensable separation method in many research fields and production workshops The separation column is an important actuator in the preparation of liquid chromatography The basic requirements of preparative liquid chromatography for separation column are high column efficiency, good selectivity and high separation speed With the development of science and technology, it has been found that pressurization on the column bed of the separation column can play two roles (A and b) or one of them: (a) accelerate the flow rate of eluent and improve the separation speed; (b) allow the use of adsorbents with smaller particle size in the separation process, so as to obtain higher resolution Therefore, there is the appearance of dynamic axial compression column (DAC) In the use process, the piston in the chromatographic column relies on the hydraulic cylinder connected with it to always produce a relatively constant pressure to compress the column bed packing, eliminating the dead space caused by the relative movement of packing particles in the elution process at any time The dynamic axial compression column is well used and can meet the purification and separation requirements of many target products The big advantage of Zui is that it is suitable for large-scale industrial production But for the technological separation of products in the laboratory research stage, the dynamic axial compression column is bulky, inconvenient and expensive Because in the laboratory, different targets, different processes and different fillers are needed as carriers of stationary phase or stationary phase In particular, the structure of sensitive compounds may change when they are separated by atmospheric pressure chromatography for a long time These two problems are often encountered in the separation of natural products At this time, the basic requirement of Zui is to shorten the separation time and achieve rapid separation to avoid this change Radial high pressure cylinder is developed to meet this need 2、 The basic structure and technical characteristics of radial high pressure cylinder: the unit of radial high pressure cylinder mainly includes: high pressure cylinder assembly, outer sleeve of cylinder, flange assembly of cylinder, loading port, outer interface, packing inside the column, etc The basic structure of the radial high pressure cylinder: the high pressure cylinder is the key component of the radial high pressure cylinder It consists of two 316L inner wall tubes and outer wall tubes, which form the main part of cylinder, sieve plate, port plate and other important auxiliary parts The inner and outer wall tubes of the cylinder are inlaid with microporous sieve plates, the pore diameter of which is smaller than that of the packing in the column At the same time, the inner and outer wall tubes of the cylinder are provided with flow distribution plates to restrict the flow direction and flow rate, so as to ensure that the flow rate of the liquid flowing into the high-pressure cylinder is equal on each differential area of the cylinder expansion surface The outer cylinder of the column plays an overall supporting role and is closed with the outer wall tube of the column to form a liquid flow outer cavity, which is a liquid flow distribution or collection cavity In the design, the chamber needs to be as small as possible on the basis of meeting the liquid flow distribution, so as to reduce the dead volume and avoid the diffusion of sample or target in the reagent The inner space of the inner tube of the inner tube of the cylinder forms the inner cavity of the radial cylinder, which is the same as the requirement of the minimum volume of the outer cavity of the liquid flow The filling parts are designed for the inner cavity The materials of the filling parts are peek and 316L stainless steel for the user to choose The column flange seals the whole high pressure column structure The cylinder flange is designed with a liquid inlet, a liquid outlet and two external interfaces for the mobile phase The packing in the column shall be selected according to the specific process requirements 3、 Filling and application of radial high pressure cylinder 1 The radial high pressure cylinder is equipped with a special loading machine The operation of the column loader is relatively easy You can refer to the manual and learn to operate it in a short time Before column loading, the filler shall be added into the homogenate and stirred to form a thin paste The column loader can output the thin filler and the column loading liquid at the same time When installing the column, first close the external interfaces of two mobile phases, and at the same time open the liquid outlet of the column The thin packing and the column loading liquid are injected into the column loading port by the column loading machine at low speed and high pressure, and flow to the outlet position The packing is blocked by the sieve plate, and starts to deposit upward at the outlet of the column The high pressure scouring of the column loading liquid makes the packing in the cylinder tend to be uniform and dense until the whole cylinder is filled Continue to flush the packing in the cylinder with high pressure, balance the pressure in the column, so as to form a stable column bed Disconnect the column installation pipeline, close the column installation port and liquid outlet, and move the radial high-pressure cylinder away for standby 2 Before separation, make sure that the loading port and liquid outlet are closed According to different samples and separation strategies, two different working modes can be selected for the radial high-pressure cylinder, i.e from the inner chamber to the outer chamber (the outer interface I is the liquid inlet) and from the outer chamber to the inner chamber (the outer interface II is the liquid inlet) The working mode of the inner cavity into the outer cavity is as follows Conclusion as a new mode of preparing chromatographic column, Zui of radial high-pressure cylinder is flexible and convenient Users can choose different cylinders and fill different fillers according to their own needs Taking the area of the column bed of 60cm2 and the thickness of the column bed of 5cm as an example, if a dynamic axial compression column is selected, a column tube with a diameter of 20cm at least, i.e dac200 dynamic axial compression column, is required On the contrary, if radial high-pressure cylinder column is selected, one of the options is: inner wall of column bed is 2cm, outer wall of column bed is 12cm, and height is 10cm One of the options: the inner wall of the column bed is 4cm, the outer wall of the column bed is 14cm, and the height is 5cm Of course, it can also be selected according to the total volume of packing in the column Either way, compared with the dynamic axial compression column, the radial high pressure cylinder column has the advantages of convenient use and low price for large area TLC According to the current market situation, in the above selection, the purchase cost of equipment: s (dynamic axial compression column): s (radial high pressure cylinder column) = 3:1.