Molecular weight determination method of polyethyleneimine

Abstract

The invention belongs to the technical field of analysis and testing, and particularly relates to a molecular weight determination method of polyethyleneimine. The molecular weight determination method of polyethyleneimine comprises the following steps: S1, preparing N standard solutions by adopting N polyethylene glycol standard samples with different molecular weight levels, and preparing a solution to be detected by adopting a polyethyleneimine sample to be detected; s2, a gel permeation chromatograph is adopted for testing and collecting chromatographic data of the N standard solutions and the to-be-detected solution, and the testing conditions include that an acetic acid-sodium acetate buffer solution serves as a mobile phase, the concentration is 0.03-0.07 mol / L, and a chromatographic column is a chromatographic column set formed by connecting at least two PL aquagel-OH in series; s3, making a standard curve according to the collected chromatographic data of the N standard solutions, and determining the molecular weight information of the to-be-detected polyethyleneimine sample according to the collected chromatographic data of the to-be-detected solution and the standard curve. According to the method provided by the invention, the accuracy of a test result of the low-molecular-weight polyethyleneimine is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of analysis and testing, and particularly relates to a method for determining the molecular weight of polyethyleneimine. Background Art

[0002] Polyethyleneimine (PEI), also known as polyaziridine, is both a water-soluble polymer and a colorless or light yellow viscous liquid. It is easy to react with electrophilic reagents or be modified by amine reactions, and has good affinity and adsorption for anionic substances. Polyethyleneimine materials are widely used in semiconductors, aerospace, electronics, chemical industry and other fields. Polyethyleneimine (PEI), as a photosensitive polymer, is an important photoresist base material. It can be used to manufacture photolithographic patterns through chemical reactions and electron beam exposure. It has excellent thermal conductivity, insulation, chemical corrosion resistance and high temperature stability.

[0003] Polyethyleneimine can be obtained with different properties according to different polymerization methods and synthesis processes, such as high temperature polyethyleneimine (HTPI) and ultra-high temperature polyethyleneimine (UHTPI). The composition of polyethyleneimine, such as molecular weight and distribution, has an important influence on its various application properties, but the accurate determination of its molecular weight and distribution is difficult. The commonly used viscosity method is cumbersome to operate, has high error, and can only measure the viscosity average molecular weight Mv, but cannot obtain information on the dispersion index. Gel permeation chromatography (GPC) is a simple and quick method to determine the molecular weight and distribution of polymers, but because PEI samples are easily adsorbed to the chromatographic column, and PEI samples are water-soluble, the solubility in the commonly used mobile phase tetrahydrofuran (THF) is low and the response value in the GPC spectrum is low, it is difficult to accurately calibrate the PEI molecular weight, and it is necessary to eliminate non-volume exclusion effects as much as possible, that is, ion exchange, ion exclusion, ion inclusion, hydrophobic effects and other effects. Summary of the invention

[0004] The purpose of the present invention is to provide a method for determining the molecular weight of polyethyleneimine in view of the problems of large test result deviation and poor accuracy in the existing method for determining the molecular weight of polyethyleneimine, thereby improving the signal response intensity and separation degree of a sample to be tested and a standard sample, accurately determining the molecular weight information of low molecular weight polyethyleneimine, and having a simple operation method, and can be widely promoted and applied in analytical laboratories.

[0005] Specifically, the molecular weight determination method of polyethyleneimine comprises the following steps: S1. N standard solutions are prepared by using N narrow distribution polyethylene glycol molecular weight standard samples with different molecular weight levels, N is an integer ≥5, and the solution to be tested is prepared by using the polyethyleneimine sample to be tested; S2. The chromatographic data of the N standard solutions and the solution to be tested in step S1 are respectively tested and collected by using a gel permeation chromatograph, and the test conditions include: using acetic acid-sodium acetate buffer solution as the mobile phase, the concentration is 0.03-0.07 mol / L, the chromatographic column is a chromatographic column group of at least two PL aquagel-OH columns connected in series, and along the injection flow direction, the maximum value of the molecular weight linear analysis range of the front PL aquagel-OH chromatographic column is ≥ the maximum value of the molecular weight analysis range of the rear PL aquagel-OH chromatographic column; S3. A standard curve is prepared according to the collected chromatographic data of the N standard solutions, and then the molecular weight information of the polyethyleneimine sample to be tested is determined according to the collected chromatographic data of the solution to be tested and the standard curve.

[0006] In a preferred embodiment, the peak molecular weight M of the narrow distribution polyethylene glycol molecular weight standard sample is P The molecular weight of the polyol is 106-7000 g / mol, and the dispersion index is 1.00-1.10.

[0007] In a preferred embodiment, the weight average molecular weight Mw of the polyethyleneimine sample to be tested is 600-1800 g / mol, and the dispersion index is 1.00-1.10.

[0008] In a preferred embodiment, the standard solution is prepared as follows: a narrow distribution polyethylene glycol molecular weight standard sample is dissolved in ultrapure water to obtain a standard solution.

[0009] In a preferred embodiment, the mass concentration of the narrow distribution polyethylene glycol molecular weight standard sample in the standard solution is 0.03-1%.

[0010] In a preferred embodiment, the test solution is prepared as follows: the polyethyleneimine sample to be tested is dissolved in ultrapure water to obtain the test solution.

[0011] In a preferred embodiment, the mass concentration of the polyethyleneimine sample to be tested in the test solution is 0.03-1%.

[0012] In a preferred embodiment, the pH value of the acetic acid-sodium acetate buffer solution is 4-5.

[0013] In a preferred embodiment, the flow rate of the mobile phase is 0.8-1 mL / min.

[0014] In a preferred embodiment, in step S2, the test conditions include: injection volume of 50-100 μL, column temperature of 25-35°C, and detector temperature of 40-60°C.

[0015] In a preferred embodiment, the chromatographic column is a PL aquagel-OH 30 chromatographic column and / or a PL aquagel-OH 40 chromatographic column; the linear range of molecular weight of the PL aquagel-OH 30 chromatographic column is 100 to 60,000 g / mol, and the effective column efficiency N is ≥ 35,000 theoretical plates / meter; the linear range of molecular weight of the PL aquagel-OH 40 chromatographic column is 10,000 to 200,000 g / mol, and the effective column efficiency N is ≥ 35,000 theoretical plates / meter.

[0016] In a preferred embodiment, the method for preparing the standard curve is as follows: the number average molecular weight standard value Mn or the weight average molecular weight standard value Mw of N narrow distribution polyethylene glycol molecular weight standard samples are fitted with the retention time t to determine the standard curve, the order q of the obtained fitting equation is 1 to 5, and the determination coefficient R of the standard curve is 2 ≥0.99.

[0017] In a preferred embodiment, the molecular weight information includes the number average molecular weight value Mn, the weight average molecular weight value Mw and the dispersion index D.

[0018] The beneficial technical effects of the present invention are as follows: by adopting a low concentration (concentration of 0.03-0.07 mol / L) of acetic acid-sodium acetate buffer solution as a mobile phase and adopting a series of PL aquagel-OH chromatographic column groups, the signal response intensity and separation degree of a series of polyethylene glycol standard samples and a polyethyleneimine sample to be tested during gel permeation chromatography (GPC) testing are improved, the existing non-volume exclusion effect is eliminated, the molecular weight of low molecular weight polyethyleneimine is accurately determined, the accuracy and repeatability of the obtained molecular weight information results (number average molecular weight value Mn, weight average molecular weight value Mw and dispersion index D) are guaranteed, and the method has the advantages of good selectivity, strong anti-interference, high sensitivity and high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the weight average molecular weight standard curve of PEG (polyethylene glycol) in Example 1 (standard curve 1).

[0020] Figure 2 This is a graph showing the weight average molecular weight test results of the sample to be tested in Example 1.

[0021] Figure 3 This is the number average molecular weight standard curve of PEG (polyethylene glycol) in Example 1 (standard curve 2).

[0022] Figure 4 1 is a graph showing the number average molecular weight test results of the samples to be tested in Example 1. DETAILED DESCRIPTION

[0023] In the present invention, the molecular weight determination method of polyethyleneimine comprises the following steps: S1. N standard solutions are prepared by using N narrow distribution polyethylene glycol molecular weight standard samples with different molecular weight levels, N is an integer ≥5, preferably an integer of 5 to 200, such as 5, 8, 10, 20, 50, 80, 100, 150, 200 or any integer therebetween, and the solution to be tested is prepared by using the polyethyleneimine sample to be tested; S2. The chromatographic data of the N standard solutions and the solution to be tested in step S1 are respectively tested and collected by using a gel permeation chromatograph, and the test conditions include: using acetic acid-sodium acetate buffer solution as the mobile phase, the concentration is 0.03 to 0.07 mol / L, such as 0.03 mol / L, 0.04 mol / L, 0.05 mol / L, 0.06 mol / L, 0.07 mol / L or any value therebetween, and the chromatographic column is at least two PL aquagel-OH chromatographic column group connected in series, and along the injection flow direction, the maximum value of the molecular weight linear analysis range of the front PL aquagel-OH chromatographic column ≥ the maximum value of the molecular weight analysis range of the rear PL aquagel-OH chromatographic column; S3. Prepare a standard curve based on the chromatographic data of the N standard solutions collected, and then determine the molecular weight information of the polyethyleneimine sample to be tested based on the chromatographic data of the solution to be tested and the standard curve. Wherein, the chromatographic column can be a chromatographic column group of 2, 3, 4 or 5 PL aquagel-OH chromatographic columns connected in series and the maximum value of the molecular weight linear analysis range of the front PL aquagel-OH chromatographic column ≥ the maximum value of the molecular weight analysis range of the rear PL aquagel-OH chromatographic column.

[0024] In the present invention, the molecular weight of the narrow distribution polyethylene glycol molecular weight standard sample is preferably 106-7000 g / mol, such as 106, 194, 200, 238, 282, 330, 400, 420, 600, 1000, 1500, 2000, 3000, 4000, 6000, 7000 g / mol or any value therebetween; the dispersion index is preferably 1.00-1.10, such as 1.00, 1.02, 1.05, 1.08, 1.10 or any value therebetween. The molecular weight of the polyethyleneimine sample to be tested is preferably 200-6000 g / mol, such as 200, 400, 600, 800, 1000, 2000, 3000, 4000, 5000, 6000 g / mol or any value therebetween; the dispersion index is preferably 1.00-1.10, such as 1.00, 1.02, 1.05, 1.08, 1.10 or any value therebetween. Peak molecular weight M P It refers to the molecular weight corresponding to the highest peak in the polymer distribution curve.

[0025] In the present invention, the method for preparing the standard solution is preferably as follows: dissolving the narrow distribution polyethylene glycol molecular weight standard sample in ultrapure water to obtain a standard solution. The mass concentration of the narrow distribution polyethylene glycol molecular weight standard sample in the standard solution is preferably 0.03-1%, such as 0.03%, 0.05%, 0.08%, 0.1%, 0.2%, 0.5%, 0.8%, 1% or any value therebetween, which is more conducive to the separation efficiency of the standard sample molecules in the chromatography and improves the accuracy of qualitative and quantitative analysis. The dosage of the narrow distribution polyethylene glycol molecular weight standard sample is preferably 10-100 mg, such as 10 mg, 20 mg, 50 mg, 80 mg, 100 mg or any value therebetween. Specifically, the method for preparing the standard solution can be as follows: weigh the narrow distribution polyethylene glycol molecular weight standard sample and place it in a sample bottle, add ultrapure water, dissolve it for 10-20 minutes, and then filter it with a 0.22 μm PES filter element to obtain a standard solution.

[0026] In the present invention, the method for preparing the solution to be tested is preferably as follows: dissolving the polyethyleneimine sample to be tested in ultrapure water to obtain the solution to be tested. The mass concentration of the polyethyleneimine sample to be tested in the solution to be tested is preferably 0.03-1%, such as 0.03%, 0.05%, 0.08%, 0.1%, 0.2%, 0.5%, 0.8%, 1% or any value therebetween, which is more conducive to the separation efficiency of the sample molecules in the chromatography and improves the accuracy of qualitative and quantitative analysis. The amount of the polyethyleneimine sample to be tested is preferably 10-100 mg, such as 10 mg, 20 mg, 50 mg, 80 mg, 100 mg or any value therebetween. Specifically, the method for preparing the solution to be tested can be as follows: weigh the polyethyleneimine sample to be tested and place it in a sample bottle, add ultrapure water, dissolve it for 10-20 minutes, and filter it with a 0.22 μm PES filter element to obtain the solution to be tested.

[0027] In the present invention, the pH value of the acetic acid-sodium acetate buffer solution is preferably 4 to 5, such as 4, 4.2, 4.5, 4.8, 5 or any value therebetween. The pH value of the acetic acid-sodium acetate buffer solution is controlled within the above preferred range, which is more conducive to reducing the non-volume exclusion effect between the standard sample or the sample to be tested and the chromatographic column filler. The flow rate of the mobile phase is preferably 0.8 to 1 mL / min, such as 0.8 mL / min, 0.85 mL / min, 0.9 mL / min, 0.95 mL / min, 1 mL / min or any value therebetween.

[0028] In the present invention, in step S2, the test conditions may also include: the injection volume is preferably 50-100 μL, such as 50 μL, 60 μL, 70 μL, 80 μL, 90 μL, 100 μL; the column temperature is preferably 25-35°C, such as 25°C, 28°C, 30°C, 32°C, 35°C or any value therebetween; the detector temperature is preferably 40-60°C, such as 40°C, 42°C, 45°C, 48°C, 50°C, 52°C, 55°C, 58°C, 60°C or any value therebetween. Controlling the column temperature and the detector temperature within the above preferred range is more conducive to reducing detector noise and baseline drift, and a stable baseline allows for better selection of the baseline and integration limit during analysis, thereby improving the accuracy and repeatability of the results.

[0029] In the present invention, the chromatographic column is preferably a PL aquagel-OH 30 chromatographic column and / or a PL aquagel-OH 40 chromatographic column. The molecular weight linear range of the PL aquagel-OH 30 chromatographic column is preferably 100 to 60000 g / mol, the effective column efficiency N≥35000 theoretical plates / meter, and the filler particle size is preferably 6 to 10 μm, such as 6 μm, 7 μm, 8 μm, 9 μm, 10 μm or any value therebetween. The molecular weight linear range of the PL aquagel-OH 40 chromatographic column is preferably 10000 to 200000 g / mol, the effective column efficiency N≥35000 theoretical plates / meter, and the filler particle size is preferably 8 to 15 μm, such as 8 μm, 10 μm, 12 μm, 14 μm, 15 μm or any value therebetween. The molecular weight linear range can be any one of the number average molecular weight, weight average molecular weight, Z average molecular weight, and viscosity average molecular weight.

[0030] In the present invention, the method for preparing the standard curve is preferably as follows: the number average molecular weight standard value Mn or the weight average molecular weight standard value Mw of N narrow distribution polyethylene glycol molecular weight standard samples are fitted with the retention time t to determine the standard curve, and the order q of the obtained fitting equation can be 1 to 5, such as 1, 2, 3, 4 or 5, q is preferably 2 or 3, and the determination coefficient R of the standard curve is 2 ≥0.99.

[0031] The present invention will be described in detail below through specific embodiments.

[0032] The instruments used in the following examples and comparative examples are as follows: gel permeation chromatograph, 1260 Infinity II GPC / SEC system from Agilent Technologies, USA; differential refractive index detector, 1260 Infinity II RID from Agilent Technologies, USA, which is a HPLC differential refractive index detector (RID).

[0033] Example 1

[0034] S1. Accurately weigh a certain mass of 5 narrow distribution polyethylene glycol (PEG) standard samples with peak molecular weights of 106, 600, 1500, 4000, and 7000 g / mol and dispersion index D of 1, place them in a sample bottle, add ultrapure water to make the mass concentration of PEG 0.5%, the sample dissolution time is 15 min, and then filter through a 0.22 μm PES filter to obtain a standard solution; weigh 50 mg of polyethyleneimine (PEI) test sample A (purchased from Anaiji Chemical Company, Mn=565 g / mol, Mw=600 g / mol, dispersion index D is 1.06), place it in a sample bottle, add ultrapure water to make the mass concentration of PEI 0.5%, the sample dissolution time is 15 min, and then filter through a 0.22 μm PES filter to obtain a test solution;

[0035] S2. Prepare acetic acid-sodium acetate buffer solution with a concentration of 0.05 mol / L and a pH of 4.5, filter it with a 0.22 μm water filter cartridge, and shake it to remove bubbles before use as the mobile phase; use a gel permeation chromatograph to test and collect chromatographic data of the five standard solutions and the test solution in step S1, respectively, and the test conditions include: setting the column temperature of the chromatographic column to 30°C, the detector temperature to 50°C, the flow rate of the mobile phase during the test to 1.0 mL / min, the injection volume to 75 μL, the sample running time to 40 min, and the chromatographic column to be a chromatographic column group composed of a PL aquagel-OH 40 column and two PL aquagel-OH 30 columns connected in series in the injection flow direction; according to the program set by the software, the automatic sampler starts the injection test and collects chromatographic data after the flow rate is stabilized to 1.0 mL / min, the pressure is stable, the temperature is stable, and the instrument baseline is stable;

[0036] S3. Input the weight average molecular weight standard values ​​of the five narrow distribution PEG standard samples in step S2, and calculate the cubic fitting curve (cubic function) of the weight average molecular weight Mw of the standard samples and the retention time t as the standard curve 1 through the GPC data analysis software. The fitting result is as follows: Figure 1 As shown, the formula of standard curve 1 is Y = -0.000499604x 3 +0.0221164x 2 -0.45881x+8.65568, R 2 is 0.995; input the number average molecular weight standard values ​​of the 5 narrow distribution PEG standard samples in step S2, and calculate the cubic fitting curve of the number average molecular weight Mn of the standard sample and the retention time t through the GPC data analysis software as the standard curve 2. The fitting result is as follows Figure 3 As shown, the formula of standard curve 2 is Y = -0.000366519x 3 -0.0422536x 2+1.12951x-4.37426, R 2 is 0.995; the chromatogram data of PEG sample A is processed according to standard curve 1, and the results are as follows Figure 2 As shown, the chromatogram data of PEG sample A is processed according to standard curve 2, and the results are as follows Figure 4 As shown, the number average molecular weight Mnˋ of the PEG test sample A is 558 g / mol, the weight average molecular weight Mwˋ is 607 g / mol and the dispersion index Dˋ (D=Mw / Mn) is 1.09, which are within 3% of the results provided by the manufacturer. This shows that the method provided by the present invention can accurately detect the small molecular weight part of polyethyleneimine and can truly reflect the information of molecular weight and dispersion index.

[0037] Example 2

[0038] The molecular weight information of the polyethyleneimine sample B (PEI, purchased from Anage Chemical Company, Mn = 770 g / mol, Mw = 800 g / mol, and dispersion index D of 1.04) was determined according to the method in Example 1. The number average molecular weight Mn was 755 g / mol, the weight average molecular weight Mw was 810 g / mol, and the dispersion index D (D = Mw / Mn) was 1.07, which was within 3.5% of the result provided by the manufacturer. This shows that the method provided by the present invention can accurately detect the molecular weight and dispersion index information of polyethyleneimine.

[0039] Example 3

[0040] The molecular weight information of the polyethyleneimine sample A was determined according to the method in Example 1, except that an acetic acid-sodium acetate buffer solution with a concentration of 0.03 mol / L was used instead of an acetic acid-sodium acetate buffer solution with a concentration of 0.05 mol / L in step S2, and the other conditions were the same as in Example 1. The number average molecular weight Mnˋ of the polyethyleneimine sample A was measured to be 590 g / mol, the weight average molecular weight Mwˋ was 615 g / mol, and the dispersion index Dˋ (D = Mw / Mn) was 1.04, which were within 4.5% of the results provided by the manufacturer. This shows that the method provided by the present invention can accurately detect the molecular weight and dispersion index information of polyethyleneimine.

[0041] Example 4

[0042] The molecular weight information of the polyethyleneimine sample A was determined according to the method in Example 1, except that an acetic acid-sodium acetate buffer solution with a concentration of 0.07 mol / L was used instead of an acetic acid-sodium acetate buffer solution with a concentration of 0.05 mol / L in step S2, and the other conditions were the same as in Example 1. The number average molecular weight Mnˋ of the polyethyleneimine sample A was measured to be 546 g / mol, the weight average molecular weight Mwˋ was 590 g / mol, and the dispersion index Dˋ (D = Mw / Mn) was 1.08, which were within 3.5% of the results provided by the manufacturer. This shows that the method provided by the present invention can accurately detect the molecular weight and dispersion index information of polyethyleneimine.

[0043] Comparative Example 1

[0044] S1. Prepare the standard solution and the test solution according to the method of step S1 in Example 1.

[0045] S2. Chromatographic data of the standard solution and the test solution are collected according to the method of step S2 in Example 1, except that an acetic acid-sodium acetate buffer solution having a concentration of 0.5 mol / L is used instead of an acetic acid-sodium acetate buffer solution having a concentration of 0.05 mol / L, and the other conditions are the same as step S1 in Example 1;

[0046] S3. Standard curve 1 and standard curve 2 were fitted according to the method of step S3 in Example 1, and the chromatogram data of the PEG sample to be tested was processed according to the standard curve. The number average molecular weight Mn of the PEG sample to be tested was 841 g / mol, the weight average molecular weight Mw was 956 g / mol, and the dispersion index D (D = Mw / Mn) was 1.14, which were significantly different from the results provided by the manufacturer (Mn deviation was 49%, Mw deviation was 59%, and D deviation was 7%).

[0047] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention.

Claims

1. A method for determining the molecular weight of polyethyleneimine, characterized in that: The molecular weight determination method of the polyethyleneimine comprises the following steps: S1. N standard solutions are prepared using N narrow distribution polyethylene glycol molecular weight standard samples of different molecular weight levels, where N is an integer ≥ 5, and the test solution is prepared using the polyethyleneimine sample to be tested; S2. Using a gel permeation chromatograph to test and collect chromatographic data of the N standard solutions and the test solution in step S1, respectively, the test conditions include: using an acetic acid-sodium acetate buffer solution as a mobile phase, the concentration is 0.03-0.07 mol / L, the chromatographic column is a chromatographic column set of at least two PL aquagel-OH columns connected in series, and along the injection flow direction, the maximum value of the molecular weight linear analysis range of the front PL aquagel-OH chromatographic column is ≥ the maximum value of the molecular weight analysis range of the rear PL aquagel-OH chromatographic column; S3. A standard curve is prepared according to the collected chromatographic data of the N standard solutions, and then the molecular weight information of the polyethyleneimine sample to be tested is determined according to the collected chromatographic data of the solution to be tested and the standard curve.

2. The method for determining the molecular weight of polyethyleneimine according to claim 1, wherein The peak molecular weight M of the narrow distribution polyethylene glycol molecular weight standard sample P The molecular weight of the polyethyleneimine sample to be tested is 106-7000 g / mol, and the dispersion index is 1.00-1.10; preferably, the weight average molecular weight Mw of the polyethyleneimine sample to be tested is 600-1800 g / mol, and the dispersion index is 1.0-1.

10.

3. The method for determining the molecular weight of polyethyleneimine according to claim 1, wherein The standard solution is prepared as follows: dissolving a narrow distribution polyethylene glycol molecular weight standard sample in ultrapure water to obtain a standard solution; preferably, the mass concentration of the narrow distribution polyethylene glycol molecular weight standard sample in the standard solution is 0.03-1%.

4. The method for determining the molecular weight of polyethyleneimine according to claim 1, wherein The method for preparing the test solution is as follows: dissolving the polyethyleneimine sample to be tested in ultrapure water to obtain the test solution; preferably, the mass concentration of the polyethyleneimine sample to be tested in the test solution is 0.03-1%.

5. The method for determining the molecular weight of polyethyleneimine according to claim 1, wherein The pH value of the acetic acid-sodium acetate buffer solution is 4-5; preferably, the flow rate of the mobile phase is 0.8-1 mL / min.

6. The method for determining the molecular weight of polyethyleneimine according to claim 1, wherein In step S2, the test conditions include: injection volume of 50-100 μL, column temperature of 25-35°C, and detector temperature of 40-60°C.

7. The method for determining the molecular weight of polyethyleneimine according to claim 1, wherein The chromatographic column is a PLaquagel-OH 30 chromatographic column and / or a PLaquagel-OH 40 chromatographic column; the molecular weight linear analysis range of the PLaquagel-OH 30 chromatographic column is 100 to 60,000 g / mol, and the effective column efficiency N is ≥35,000 theoretical plates / meter; the molecular weight linear analysis range of the PLaquagel-OH 40 chromatographic column is 10,000 to 200,000 g / mol, and the effective column efficiency N is ≥35,000 theoretical plates / meter.

8. The method for determining the molecular weight of polyethyleneimine according to claim 1, wherein The method for preparing the standard curve is as follows: the number average molecular weight standard value Mn or the weight average molecular weight standard value Mw of N narrow distribution polyethylene glycol molecular weight standard samples are fitted with the retention time t to determine the standard curve, the order q of the obtained fitting equation is 1 to 5, and the determination coefficient R of the standard curve is 2 ≥0.

99.

9. The method for determining the molecular weight of polyethyleneimine according to claim 1, wherein The molecular weight information includes the number average molecular weight value Mn, the weight average molecular weight value Mw and the dispersion index D.

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