Method for designing preparative chromatography column dimensions using analytical chromatography data

Abstract

This invention discloses a method for designing and preparing chromatographic column sizes using analytical chromatographic data, including mixed gas preparation, component identification, motion time calculation, column length calculation, and column length adjustment. In this method, a mixed gas is prepared, component B is identified, and component A, which is the most difficult to separate from component B and whose peak elutes before component B, is selected. The design is based on the point where components A and B are just separated. The motion time of component A in the chromatographic column is obtained through injection, and the initial column length is determined. When the column length is too long, the column size is adjusted appropriately. This invention establishes a simple and easy-to-understand method for rapidly designing and preparing chromatographic column sizes using analytical chromatographic data. It can predict, to some extent, the separation and preparation effect of the column on components of interest, such as resolution and peak width, reducing experimental frequency and material and energy consumption, lowering labor costs, and saving time.

Description

Technical Field

[0001] This invention relates to chromatographic column preparation technology, specifically a method for designing and preparing chromatographic column dimensions using analytical chromatographic data. Background Technology

[0002] Preparative chromatography is one of the most effective preparative separation techniques in separation science, and it is an indispensable separation and purification method in many research fields and production workshops. Preparative chromatography columns are key equipment in preparative chromatographic separation, primarily targeting the preparation of one or more components from a specific volume of mixture, exhibiting high selectivity. General-purpose preparative chromatography columns (mainly commonly used liquid chromatography columns) are readily available on the market, while non-general-purpose columns (such as gas chromatography columns) are difficult to find suitable options, requiring users to design their own. Currently, patents and literature related to preparative chromatography columns mainly focus on the improvement and development of packing materials (application numbers CN202110373403.0, etc.) and the design and fabrication of structures (application numbers 201920604966.4, 201821045868.3, etc.), with no technical solutions involving column size design found.

[0003] A preparative chromatography column of suitable size can achieve the purpose of component separation and recovery, while also reducing preparative separation time, improving separation efficiency, and saving energy and material consumption. Therefore, it is necessary to establish a simple and easy-to-implement method for designing the size of preparative chromatography columns. Summary of the Invention

[0004] The purpose of this invention is to provide a method for designing and preparing chromatographic column sizes using analytical chromatographic data, in order to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A method for designing and preparing chromatographic column sizes using analytical chromatographic data, the method comprising the following steps:

[0007] Step 1: Preparation of mixed gas;

[0008] Step Two:

[0009] S1: Confirmation of mixed gas components, including component A and component B, confirmation of the preparation of component B, selection of component A which is most difficult to separate from component B, assuming that when preparing component B in the mixed gas, component A is the most difficult to separate from component B, and component A elutes its peak before component B.

[0010] It also includes a method for obtaining velocity data of gas axial movement in the chromatographic column, which treats the chromatographic peak (including the penetration point and desorption point) as a relatively stable moving object. During the chromatographic separation process, its shape and velocity along the chromatographic column remain unchanged, and the velocity data of gas axial movement in the chromatographic column are obtained based on this.

[0011] S2: Based on the composition of the pre-prepared mixed gas, roughly estimate the applicable chromatographic packing material, the operating temperature of the preparative chromatography, and the range of carrier gas flow rates.

[0012] S3: Using an analytical chromatographic column, within the predicted operating temperature and carrier gas flow rate range, test the breakthrough time and desorption time of component A and component B;

[0013] S4: Calculate the average velocity of the breakthrough and desorption points along the axial direction in the column using column length, component breakthrough time, and desorption time. ;

[0014] S5: Empirical formulas for the axial velocity of the penetration and desorption points in relation to column temperature T and carrier gas flow rate F are obtained using software fitting. ;

[0015] Step 3: This also includes the design method for preparing the chromatographic column during isothermal separation: Calculation of the travel time and velocity of the desorption point of component A: The design is based on the point where components A and B just separate, meaning the axial distance traveled by the desorption point of component A in the column is equal to the axial distance traveled by the penetration point of component B in the column, thus obtaining the travel time of component A in the column.

[0016] S1: The chromatographic column separation is divided into an injection process and a separation process, with the injection time being... The separation process takes time. The flow rate is F, and the column temperature is T.

[0017] S2: Desorption point analysis of component A. The desorption point of component A only undergoes the separation process, and the movement time is... The speed of movement is The distance of the movement ;

[0018] S3: Component B penetration point analysis. The component B penetration point underwent the injection and separation processes, with a travel time of [time missing]. The speed of movement is The distance of the movement ;

[0019] S4: Separation time calculation, the distance traveled by component A at the desorption point is equal to the distance traveled by component B at the penetration point, i.e. The separation time was calculated. ;

[0020] Step 4: Column Length Calculation. Based on the travel time and velocity of component A's desorption point within the column, the preliminary column length of the preparative column is obtained. Its inner diameter is the same as that of the analytical column. The column length calculation shows that the distance traveled by component A's desorption point is the column length of the preparative column with an inner diameter of 2 mm. ;

[0021] Step 5: Column length adjustment. When the column length is relatively long, based on the principle that the dynamic adsorption coefficient of the component on the adsorbent remains basically unchanged under certain conditions, i.e. within a certain range of flow rate, temperature and pressure, the column size is adjusted appropriately while keeping the average gas linear velocity, temperature and pressure basically unchanged.

[0022] As a further aspect of the present invention: In step three, when injecting the sample, if the chromatographic injection volume is greater than 1 ml or the injection time is longer than 1 min, the injection time is divided into n equal parts, such as 0.5 min as one part, 1 min as one part, and the chromatographic elution curve of a single part is as follows: The concentration value of a chromatographic peak component is the sum of the contributions of n sample injections at that point. The sample injected at time n=1 contributes the most to the breakthrough point concentration, followed by the sample injected at time n=2, whose contribution rate is much smaller than that of the first sample. Samples injected at other times contribute even less to the breakthrough point concentration. For ease of data processing, only the contribution of the first sample is considered, i.e., the breakthrough point movement time includes the injection time. The breakthrough point movement time is selected from the sample time of the first sample. The sample injected at time n contributes the most to the desorption point concentration, followed by the sample injected at time n-1, whose contribution rate is much smaller than that of the sample injected at time n. Samples injected at other times contribute even less to the desorption point concentration. For ease of data processing, only the contribution of the last sample is considered, i.e., the desorption point movement time does not include the injection time. The desorption point movement time is selected from the sample time of the last sample.

[0023] As a further aspect of the present invention: the column length calculation in step four should reserve a certain amount of redundancy, preferably 30% redundancy.

[0024] As a further aspect of the present invention: in step five, column length adjustment, when the column length of the preparation chromatography column is too long to function properly, it is necessary to adjust the column length according to the principle that the dynamic adsorption coefficient of the component on the adsorbent remains unchanged under certain conditions, while keeping the average gas linear velocity, temperature, and pressure essentially constant, based on the formula... Adjust the inner diameter of the column appropriately, from The column length was calculated.

[0025] As a further aspect of the present invention, it also includes a method for designing a chromatographic column for temperature-programmed separation, the method comprising the following steps:

[0026] Step 1: The chromatographic column separation is divided into four processes: sample injection, low-temperature separation, temperature-programmed separation, and high-temperature separation. The times for each of the four processes are as follows: , , , The flow rate is F, and the low temperature during the programmed heating is... High temperature is The programmed heating rate is K;

[0027] Step 2: Analysis of the desorption point of component A. The desorption point of component A undergoes three processes: low-temperature separation, programmed temperature separation, and high-temperature separation. The total distance traveled is... ;

[0028] Step 3: Component B breakthrough point analysis. Component B's breakthrough point undergoes four processes: sample introduction, low-temperature separation, temperature-programmed separation, and high-temperature separation. The total distance traveled is... ;

[0029] Step 4: Calculation of high-temperature separation time. The distance traveled by component A at the desorption point is equal to the distance traveled by component B at the penetration point, i.e. The high-temperature separation time was calculated. ;

[0030] Step 5: Column length calculation. The distance traveled by the desorption point of component A is the column length L1 of the preparative chromatography column with an inner diameter of 2 mm.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] This invention establishes a simple and easy-to-understand method for rapidly designing and preparing chromatographic column sizes using analytical chromatographic data. It can predict to some extent the separation and preparation effect of the prepared chromatographic column on the components of interest, such as resolution and peak width. This can reduce the frequency of experiments and the consumption of materials and energy, reduce labor costs, and save time. Attached Figure Description

[0033] Figure 1 A graph showing the peak penetration point and desorption point curves in a method for designing and preparing chromatographic column sizes using analytical chromatographic data.

[0034] Figure 2 This diagram illustrates the separation process and conditions during isothermal separation preparation in a method for designing and preparing chromatographic column sizes using analytical chromatographic data.

[0035] Figure 3 This diagram illustrates the separation process and conditions during programmed temperature separation in a method for designing and preparing chromatographic column sizes using analytical chromatographic data. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Please see Figures 1-3 In this embodiment of the invention, a method for designing and preparing chromatographic column sizes using analytical chromatographic data is provided, and the method steps are as follows:

[0038] Step 1: Preparation of mixed gas;

[0039] Step 2: Component identification. Identify component B and select component A, which is the most difficult to separate from component B. Assume that when preparing component B in the mixed gas, component A is the most difficult to separate from component B, and component A elutes from the chromatographic column before component B.

[0040] Step 3: Calculate the motion time. Take the point where component A and component B just separate as the starting point for design or calculation. That is, the distance that component A travels along the axial direction in the chromatographic column from the desorption point is equal to the distance that component B travels along the axial direction in the chromatographic column. This gives the time that component A travels in the chromatographic column.

[0041] Step 4: Column length calculation. By measuring the time it takes for component A to move through the chromatographic column, the column length of the preparative chromatographic column is initially obtained. Its inner diameter is the same as that of the analytical chromatographic column.

[0042] Step 5: Column length adjustment. When the column length is too long and cannot work properly, based on the principle that the dynamic adsorption coefficient of the component on the adsorbent remains basically unchanged under certain conditions, i.e. within a certain range of flow rate, temperature and pressure, the column size is adjusted appropriately while keeping the average gas linear velocity, temperature and pressure basically unchanged.

[0043] In step three, when injecting the sample, if the injection volume is greater than 1 ml or the injection time is longer than 1 min, the injection time is divided into n equal parts, such as 0.5 min as one part, 1 min as another part, and the chromatographic elution curve of a single part is as follows. The concentration value of a chromatographic peak component is the sum of the contributions of n sample injections at that point. The sample injected at time n=1 contributes the most to the breakthrough point concentration, followed by the sample injected at time n=2, whose contribution is much smaller than that of the first sample. Samples injected at other times contribute even less to the breakthrough point concentration. For ease of data processing, only the contribution of the first sample is considered, i.e., the breakthrough point movement time includes the injection time. The breakthrough point movement time is selected as the sample time of the first sample. The sample injected at time n contributes the most to the desorption point concentration, followed by the sample injected at time n-1, whose contribution is much smaller than that of the sample injected at time n. Samples injected at other times contribute even less to the desorption point concentration. For ease of data processing, only the contribution of the last sample is considered, i.e., the desorption point movement time does not include the injection time. The desorption point movement time is selected as the sample time of the last sample.

[0044] In step four, the column length calculation should allow for a certain amount of redundancy, preferably 30% redundancy.

[0045] In step five, column length adjustment is necessary when the preparative chromatographic column is too long to function properly. This requires adhering to the principle that the dynamic adsorption coefficient of the component on the adsorbent remains constant under certain conditions. While maintaining a constant average gas linear velocity, temperature, and pressure, the adjustment should be performed according to the formula... Adjust the inner diameter of the column appropriately, from The column length was calculated.

[0046] It also includes a method for obtaining velocity data of gas moving axially in the chromatographic column. This method treats the chromatographic peak (including the penetration point and desorption point) as a relatively stable moving object, whose shape and velocity along the column axis remain unchanged during chromatographic separation. Based on this, the velocity data of gas moving axially in the chromatographic column are obtained. The method steps are as follows:

[0047] Step 1: Based on the composition of the pre-prepared mixed gas, roughly estimate the applicable chromatographic packing material, the operating temperature of the preparative chromatography, and the range of carrier gas flow rates.

[0048] Step 2: Using an analytical column of appropriate length, close to that of the preparative column, with a diameter of 2 mm, test the breakthrough time and desorption time of component A and component B within the predicted operating temperature and carrier gas flow rate range.

[0049] Step 3: Calculate the average velocity of the breakthrough and desorption points along the axial direction within the column using the column length, component breakthrough time, and desorption time. ;

[0050] Step 4: Use software fitting to obtain empirical formulas for the axial velocity of the penetration point and desorption point in relation to column temperature T and carrier gas flow rate F. ;

[0051] It also includes a method for designing chromatographic columns for isothermal separation, the steps of which are as follows:

[0052] Step 1: The chromatographic column separation is divided into an injection process and a separation process. The injection time is... The separation process takes time. The flow rate is F, and the column temperature is T.

[0053] Step 2: Desorption point analysis of component A. The desorption point of component A only undergoes the separation process, and the movement time is... The speed of movement is The distance of the movement ;

[0054] Step 3: Component B breakthrough point analysis. The breakthrough point of component B has undergone the injection and separation processes, with a travel time of [time missing]. The speed of movement is The distance of the movement ;

[0055] Step 4: Separation time calculation. The distance traveled by component A at the desorption point is equal to the distance traveled by component B at the penetration point, i.e. The separation time was calculated. ;

[0056] Step 5: Column length calculation. The distance traveled by component A at its desorption point is the column length of the preparative chromatography column with an inner diameter of 2 mm. The column length is... .

[0057] It also includes a method for designing chromatographic columns for temperature-programmed separation, the steps of which are as follows:

[0058] Step 1: The chromatographic column separation is divided into four processes: sample injection, low-temperature separation, temperature-programmed separation, and high-temperature separation. The times for each of the four processes are as follows: , , , The flow rate is F, and the low temperature during the programmed heating is... High temperature is The programmed heating rate is K;

[0059] Step 2: Analysis of the desorption point of component A. The desorption point of component A undergoes three processes: low-temperature separation, programmed temperature separation, and high-temperature separation. The total distance traveled is... ;

[0060] Step 3: Component B breakthrough point analysis. Component B's breakthrough point undergoes four processes: sample introduction, low-temperature separation, temperature-programmed separation, and high-temperature separation. The total distance traveled is... ;

[0061] Step 4: Calculation of high-temperature separation time. The distance traveled by component A at the desorption point is equal to the distance traveled by component B at the penetration point, i.e. The high-temperature separation time was calculated. ;

[0062] Step 5: Column length calculation. The distance traveled by the desorption point of component A is the column length L1 of the preparative chromatography column with an inner diameter of 2 mm.

[0063] The time required for the concentration of the adsorbate in the gas flowing out of the chromatographic column to reach a predetermined value is called the breakthrough time. Figure 1 middle This point is called the breakthrough point, and this predetermined value is usually taken as 5% to 10% of the feed gas concentration; here, 5% of the highest concentration is used. The time required for the concentration of the adsorbate in the gas effluent from the column to reach a certain predetermined value is called the desorption time. Figure 1 middle This point is called the desorption point, and this predetermined value is 5%.

[0064] Example 1:

[0065] Assuming a temperature-programmed method is used to separate and prepare a mixed gas (containing...) , , , (etc.) The selected chromatographic packing material is Porapak Q. This will be used as an example for design. Preparation of the chromatographic column. On the Porapak Q column, the component most difficult to separate from Xe is... ,and Compare The first peak emerges.

[0066] Get Gas and Axial velocity data of gas at the breakthrough point and desorption point in a Porapak Q analytical column. A 4m long, 2mm inner diameter Porapak Q column was used at a column temperature of 30-110℃ and a carrier gas flow rate of 10-30 cm³. 3 At / min, the analysis was performed , Retention time, peak width, breakthrough time, and desorption time, using The average axial velocities of the breakthrough point and desorption point in the chromatographic column were calculated, and empirical formulas were obtained using software fitting to correlate the axial velocities of the breakthrough point and desorption point with column temperature T and carrier gas flow rate F. , Formula for calculating peak penetration velocity , Formula for calculating peak desorption point velocity , Formula for calculating peak penetration velocity , Formula for calculating peak desorption point velocity .

[0067] When using programmed temperature separation, the carrier gas flow rate F = 10 mL / min, the injection volume 500 mL, and the low temperature are set. =30℃, high temperature Under the conditions of 100℃, programmed temperature rise rate K=40℃ / min, and low-temperature separation time being 0.3 times the injection time, =50min, =0.3 × 50 min = 15 min, =1.75min, high-temperature separation time unknown. The total distance traveled by the peak desorption point . The total distance traveled by the peak penetration point .Depend on Calculate Therefore, it can be calculated that when the inner diameter is 2mm Column length for preparation of chromatographic columns =3683cm. The column length is too long to function properly. It is necessary to adhere to the principle that the dynamic adsorption coefficient of the component on the adsorbent remains constant under certain conditions, while keeping the average gas linear velocity, temperature, and pressure essentially constant, according to the formula... , Adjust the column inner diameter and column length appropriately, and take the inner diameter of the preparative chromatographic column. Column length =6.52m. The corresponding flow rate at this time is =56 mL / min. Redundancy is not considered here.

[0068] Preparative chromatographic column separation and Separation at time and Peak width calculation. Using... , Formulas for the axial velocity of the penetration point and desorption point in the chromatographic column, and calculations. Through time, Desorption time, Through time, The desorption time was used, and the separation degree R of the two gases was calculated to be 1.55 using the formula for separation degree and peak width. Peak width W = 3.87 min Retention time =26.6min.

[0069] Through experimental testing Preparative chromatographic column separation and Separation at time and Peak width, separation degree between the two gases R=1.46, Peak width W = 3.75 min Retention time =25.6min.

[0070] The calculated value has a relative deviation of 6.2% in resolution compared to the measured value. The relative deviation of peak width is 3.2%. The relative deviation of retention time was 3.9%, which is relatively small. This demonstrates that chromatographic columns can be rapidly designed and prepared using readily available analytical chromatographic data.

[0071] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for designing and preparing chromatographic column sizes using analytical chromatographic data, characterized in that: The method steps are as follows: Step 1: Preparation of mixed gas; Step Two: S1: Confirmation of mixed gas components, including component A and component B, confirmation of component B preparation, selection of component A which is the most difficult to separate from component B, and component A eluted before component B; S2: Based on the composition of the pre-prepared mixed gas, infer the applicable chromatographic packing material, the operating temperature of the preparative chromatography, and the range of carrier gas flow rates; S3: Using an analytical chromatographic column, within the predicted operating temperature and carrier gas flow rate range, test the breakthrough time and desorption time of component A and component B; S4: Calculate the average velocity of the breakthrough and desorption points along the axial direction in the column using column length, component breakthrough time, and desorption time. ; S5: Empirical formulas for the axial velocity of the penetration and desorption points in relation to column temperature T and carrier gas flow rate F are obtained using software fitting. ; Step 3: Calculation of the travel time and velocity of the desorption point of component A: The design is based on the point where components A and B just separate. That is, the axial distance traveled by the desorption point of component A in the column is equal to the axial distance traveled by the penetration point of component B in the column. This gives the travel time of component A in the column. S1: The chromatographic column separation is divided into an injection process and a separation process, with the injection time being... The separation process takes time. The flow rate is F, and the column temperature is T. S2: Desorption point analysis of component A. The desorption point of component A only undergoes the separation process, and the movement time is... The speed of movement is The distance of the movement ; S3: Component B penetration point analysis. The component B penetration point underwent the injection and separation processes, with a travel time of [time missing]. The speed of movement is The distance of the movement ; S4: Separation time calculation, the distance traveled by component A at the desorption point is equal to the distance traveled by component B at the penetration point, i.e. The separation time was calculated. ; Step 4: Column length calculation. Based on the travel time and velocity of component A's desorption point within the column, the preliminary column length is obtained: the distance traveled by component A's desorption point is the column length of the preparative column with an inner diameter of 2 mm. ; Step 5: Column length adjustment. When the column length is relatively long, based on the principle that the dynamic adsorption coefficient of the component on the adsorbent remains basically unchanged under certain conditions, the column size is adjusted appropriately while keeping the average gas linear velocity, temperature and pressure basically unchanged.

2. The method for designing and preparing chromatographic column sizes using analytical chromatographic data according to claim 1, characterized in that: In step three, when injecting the sample, if the chromatographic injection volume is greater than 1 ml or the injection time is longer than 1 min, the injection time is divided into n equal parts, and the chromatographic elution curve of a single part is as follows: The concentration value of a chromatographic peak component is the sum of the contributions of n sample injections at that point. The time of penetration point movement is selected as the sample time of the first injection, and the time of desorption point movement is selected as the sample time of the last injection.

3. The method for designing and preparing chromatographic column sizes using analytical chromatographic data according to claim 1, characterized in that: In step four, the column length calculation is reserved with a 30% redundancy.

4. The method for designing and preparing chromatographic column sizes using analytical chromatographic data according to claim 1, characterized in that: In step five, the column length is adjusted according to the formula. Adjust the inner diameter of the column appropriately, from The column length was calculated.

5. The method for designing and preparing chromatographic column sizes using analytical chromatographic data according to claim 1, characterized in that: It also includes a method for designing chromatographic columns for temperature-programmed separation, the steps of which are as follows: Step 1: The chromatographic column separation is divided into four processes: sample injection, low-temperature separation, temperature-programmed separation, and high-temperature separation. The times for each of the four processes are as follows: , , , The flow rate is F, and the low temperature during the programmed heating is... High temperature is The programmed heating rate is K; Step 2: Analysis of the desorption point of component A. The desorption point of component A undergoes three processes: low-temperature separation, programmed temperature separation, and high-temperature separation. The total distance traveled is... ; Step 3: Component B breakthrough point analysis. Component B's breakthrough point undergoes four processes: sample introduction, low-temperature separation, temperature-programmed separation, and high-temperature separation. The total distance traveled is... ; Step 4: Calculation of high-temperature separation time. The distance traveled by component A at the desorption point is equal to the distance traveled by component B at the penetration point, i.e. The high-temperature separation time was calculated. ; Step 5: Column length calculation. The distance traveled by component A at its desorption point is the column length of the preparative chromatography column with an inner diameter of 2 mm. .

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