Method and system for analyzing polymer compounds

Abstract

This polymer compound analysis method includes: a first step of employing size exclusion chromatography to separate a polymer compound contained in a sample and to acquire a chromatogram; a second step of fractionating an eluted component corresponding to one peak that includes the polymer compound, in the chromatogram, into a plurality of parts for each elution time; and a third step of employing Raman spectroscopy to measure the Raman spectrum of the fractionated eluted component.

Description

[Technical field]

[0001] The present invention relates to a method for analyzing a polymer compound and a system for analyzing a polymer compound. [Background technology]

[0002] Conventionally, in functional polymer compounds, such as engineering plastics, the composition of multiple monomers constituting the polymer compound has been controlled to give the compound desired functions. For example, AS resin is a resin that is widely used in exterior components and displays of home appliances. AS resin is a copolymer of acrylonitrile and styrene, and various functions such as transparency, scratch resistance, and heat resistance have been improved by designing and modifying the molecular weight and the composition ratio of acrylonitrile and styrene (see Patent Document 1). Therefore, it is important to accurately grasp the molecular weight and monomer composition ratio in order to improve the function and realize reproducibility of the resin. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-101230 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the composition ratio of monomers in each molecular weight region of a polymer compound may change due to various factors such as the monomer species and the manufacturing method, that is, the molecular weight dependency of the polymer compound may occur. Specifically, even in a copolymer made of the same monomer species, the monomer composition ratio in the high molecular weight region may differ from the monomer composition ratio in the low molecular weight region due to the monomer arrangement such as random copolymerization or block copolymerization, and this molecular weight dependency affects the physical properties of the entire copolymer. Therefore, in order to further improve the function and reproducibility of resins, it is required to grasp more detailed information of the polymer structure, such as the molecular weight dependency of the copolymerization composition, in addition to the molecular weight distribution and average monomer composition.

[0005] Furthermore, there is a demand for polymer compound analysis using a simple method that does not require a special environment (eg, a vacuum environment) or complicated processes (eg, high-temperature heat treatment).

[0006] An object of the present invention is to provide a method and system for easily analyzing the details of the structure of a polymer compound. [Means for solving the problem]

[0007] The analytical method and analytical system according to the first aspect of the present invention relate to the following: <Item 1> A method for analyzing a polymer compound, comprising: a first step of separating a polymer compound contained in a sample using size exclusion chromatography to obtain a chromatogram; a second step of fractionating an eluted component corresponding to one peak containing the polymer compound in the chromatogram into a plurality of fractions for each elution time; and a third step of measuring the Raman spectrum of the fractionated eluted component using Raman spectroscopy. <Item 2> The analytical method according to item 1, wherein two or more Raman spectra measured in the third step are compared. <Item 3> The analysis method according to item 1 or 2, wherein the polymer compound is a copolymer. <Item 4> The analysis method according to item 3, wherein the copolymer is a binary copolymer, a ternary copolymer or a quaternary copolymer. <Item 5> An analytical system for carrying out the method according to any one of items 1 to 4, comprising: a liquid chromatography device for separating a polymer compound contained in a sample by size exclusion chromatography to obtain a chromatogram; a fractionation device for fractionating an eluted component corresponding to one peak containing the polymer compound in the chromatogram into a plurality of fractions for each elution time; and a Raman spectrometer for measuring Raman spectra of the fractionated eluted components. Effect of the Invention

[0008] According to the invention of item 1, it is possible to obtain Raman spectra for each elution time of a polymer compound contained in one peak. According to the invention of item 2, it is possible to analyze whether the polymer compounds of the compared Raman spectra have the same composition. In addition, since polymer compounds with different molecular weights are eluted at each elution time, the details of the polymer compound structure, particularly the molecular weight distribution and the molecular weight dependency of the polymer compound composition, can be easily analyzed. According to the invention of item 3, a polymer compound in which a plurality of monomers are polymerized can be analyzed. According to the invention of item 4, a polymer compound containing two, three or four types of polymerized monomers can be analyzed. According to the invention of item 5, the molecular weight distribution of a polymer compound and the molecular weight dependency of the composition of the polymer compound can be easily analyzed. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 shows a schematic diagram of an LC apparatus and a fraction collection apparatus used in a first embodiment. [Diagram 2] The chromatogram is shown in a diagram in which the chromatogram is fractionated by elution time. [Diagram 3] FIG. 1 shows a schematic diagram of a Raman spectroscopic device used in a first embodiment. [Figure 4]FIG. 1 shows a schematic diagram of an analysis system for use in a first embodiment and examples. [Diagram 5] FIG. 1 shows a block diagram of an analysis system for use in a first embodiment. [Figure 6] 1 shows a chromatogram measured in Example 1. [Figure 7] 1 shows the Raman spectrum measured in Example 1. [Figure 8] 4 shows a chromatogram measured in Example 2. [Figure 9] 1 shows the Raman spectrum measured in Example 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] 1. First Aspect The analysis method according to the first aspect of the present invention sequentially comprises steps 1, 2, and 3. Each step will be described in detail below.

[0011] (1st step) In the first step, polymer compounds are separated from a sample using liquid chromatography (hereinafter abbreviated as "LC" (Liquid Chromatography)).

[0012] The sample (measurement sample) to be subjected to LC contains a polymer compound. From the viewpoint of analyzing the molecular weight dependency of the copolymer composition, the polymer compound is preferably a copolymer, and more preferably a copolymer made of a synthetic polymer. Specific examples include binary copolymers, terpolymers, and quaternary copolymers. The monomer arrangement of the copolymer may be any of random copolymerization, alternating copolymerization, periodic copolymerization, block copolymerization, and graft copolymerization. The type of monomer constituting the polymer is not limited, and monomers used in the field of engineering plastics and other fields can be widely adopted.

[0013] The sample may be composed of only a polymer compound, or may be a mixture containing a low molecular weight compound, a solvent, etc. The low molecular weight compound contained in the mixture can be easily separated and removed by LC, so it does not have a significant effect on the analysis of the polymer compound. The polymer compound may be a single type, or a composite of two or more types, but is preferably a single type from the viewpoint of facilitating the analysis results of each polymer compound.

[0014] In the present invention, the polymer compound refers to a polymer having a number average molecular weight of 1,000 or more (preferably 10,000 or more). Moreover, the polymer compound of the same kind refers to a polymer in which the types of constituent monomers are all the same.

[0015] LC is a type of chromatography that separates samples using a liquid as a mobile phase. In the first embodiment, LC is preferably high performance liquid chromatography (HPLC). The separation mode of LC is size exclusion chromatography (SEC). This allows separation based on molecular weight.

[0016] The eluent used in the mobile phase may be appropriately determined depending on the solubility of the polymer compound contained in the sample, and may be either an organic solvent or an aqueous solution. Examples of organic solvents include tetrahydrofuran (THF), trihydrofuran, chloroform, dimethylformamide, benzene, toluene, quinoline, o-cresol, o-dichlorobenzene, 1,2,4-trichlorobenzene, tetrachloroethane, methyl acetate, methanol, ethanol, and hexafluoroisopropanol. Examples of aqueous solutions include aqueous sodium nitrate, phosphate buffer, and acetate buffer. In the first embodiment, gel permeation chromatography (GPC) using size exclusion chromatography and an organic solvent as the mobile phase is preferred.

[0017] The sample concentration introduced into the column (i.e., the polymer concentration in the polymer-containing eluent) is, for example, 0.01% w / v or more, preferably 0.1% w / v or more, or, for example, 10% w / v or less, preferably 5% w / v or less.

[0018] The column used is a size exclusion chromatography column, such as Shimadzu Corporation's Shim-pack GPC (registered trademark), Tosoh Biosciences Corporation's TSKgel (registered trademark), Showa Denko Corporation's Shodex (registered trademark), and Fujifilm Wako Pure Chemical Corporation's Wakopak (registered trademark).

[0019] A typical LC device used for LC is illustrated in FIG. 1. The LC device 100 includes a pump 1, a sample injection section (autosampler) 2, a column 3, a detection section 4, and a computer 5, and is equipped with an eluent 6. A fractionation device 200 is connected to the LC device 100 behind the detection section 4. The eluent 6 is delivered by the pump 1, and mixed with a sample 7 in the sample injection section 2. The sample 7 mixed with the eluent 6 is introduced into the column 3, where it is separated for each elution time, detected as a chromatogram in the detection section 4, and processed by the computer 5. The separated sample 7 is sent to the fractionation device 200 together with the eluent 6 as an eluted component for the next second step, and then fractionated as a fractionation liquid 8 for each elution time range, and is provided to the third step.

[0020] In the first step, a size exclusion chromatography column is used as the column to perform size exclusion chromatography. Therefore, the polymer compounds contained in the sample are separated and discharged according to molecular weight. In addition, a chromatogram is obtained by the detection unit 4 and the computer 5, in which the horizontal axis indicates elution time and the vertical axis indicates signal intensity, as shown in FIG. 2. One or more molecular weight peaks are observed in the chromatogram. At this time, a calibration curve that correlates the molecular weight with the elution time is created using a standard substance with a known molecular weight (e.g., standard polystyrene) and is added to the chromatogram. At this time, due to the characteristics of size exclusion chromatography, the same type of polymer compound is eluted in one peak, and within one peak, the components with larger molecular weights are eluted first. In this way, information on the molecular weight distribution of the polymer compounds contained in the sample is obtained.

[0021] (2nd process) In the second step, the polymer compound is fractionated at each predetermined elution time. That is, the polymer compound is fractionated into a plurality of containers at each elution time at which one peak in the chromatogram obtained in the first step is fractionated. That is, the eluted component corresponding to one peak containing the polymer compound in the chromatogram is fractionated into a plurality of containers at each elution time.

[0022] Specifically, at least one of the peaks in the chromatogram obtained in the first step is fractionated into a plurality of peaks for each elution time (fractionation step), and then, the polymer compound is fractionated for each fractionated elution time using a fractionation device (fractionation step).

[0023] In the fractionation step, one peak in a chromatogram is fractionated into multiple peaks as shown in Fig. 2. The width of the elution time for fractionation may be appropriately determined depending on the number of fractions to be obtained, and may be freely set between 3 and 60 seconds. The number of fractions is not limited, and may be, for example, 2 or more, preferably 3 or more, and may be, for example, 100 or less, preferably 10 or less. This fractionation step may be performed simultaneously with the first step, that is, when the chromatogram is detected.

[0024] In the fractionation step, the polymer compounds (eluted components) discharged from the column together with the eluent are separated into a number of fractions based on the fractionated elution time. As a result, the polymer compounds are fractionated into molecular weights corresponding to the elution times, and fractions containing polymer compounds separated into desired molecular weight ranges are obtained.

[0025] The fractionation device used in the fractionation step separates the polymer compound (specifically, the eluted component containing the polymer compound and the eluent) into a plurality of portions and places them in a plurality of containers. As shown in FIG. 1, for example, the fractionation device 200 includes a discharge nozzle 11 for discharging the eluted component and a container moving body 12. The container moving body 12 can move one or more containers 13 to accommodate the discharged fractionated liquid 8 in a desired container 13 or a desired location in the container 13. Specific examples of the container moving body 12 include a pickup device and a conveyor. Examples of the container 13 include a sample bottle, a petri dish, and a plate (e.g., a well plate, a microplate). If a Raman spectroscopy plate is used as the container (see FIG. 4), there is no need to rearrange the container to a Raman spectroscopy plate (spotting plate) in the third step, and the third step can be smoothly performed.

[0026] In the second step, one peak in the chromatogram is divided into a plurality of fractions, and the polymer compound is separated into a plurality of fractions. This allows the monomer composition ratio in the molecular weight distribution of the same kind of polymer compound to be reliably measured. If the polymer compounds are separated from the two peaks separated from each other, the molecular weights of the separated polymer compounds may differ greatly, resulting in different kinds of polymer compounds. In other words, the sample may contain a mixture of multiple polymer compounds with different monomer types, resulting in different polymer compounds being compared with each other. As a result, the purpose of measuring the monomer composition ratio of the same kind of polymer compound may not be achieved.

[0027] In the present invention, a peak having two or more maximum values ​​in a chromatogram is also included in "one peak." In other words, a peak in which two or more peaks are close to each other and the bases of these peaks overlap each other, resulting in a unified peak, is also "one peak." Specifically, as shown in FIG. 8 measured in Example 2 described later, a peak having two maximum values ​​is also considered to be "one peak."

[0028] (3rd step) In the third step, the Raman spectrum of the fractionated solution is measured using Raman spectroscopy, that is, the Raman spectrum of the fractionated eluted component is measured using Raman spectroscopy.

[0029] Raman spectroscopy is a method for analyzing the molecular structure of a measurement object (polymeric compound contained in a fractionated solution) by detecting Raman scattered light scattered by irradiating the measurement object with light. Variations of Raman spectroscopy include, for example, Raman spectroscopy, surface-enhanced Raman spectroscopy, tip-enhanced Raman spectroscopy, resonance Raman spectroscopy, and polarized Raman spectroscopy, and various methods may be adopted depending on the purpose. In the first aspect, Raman spectroscopy is preferably used from the viewpoint of being able to uniformly measure a relatively wide area (for example, at the micro level) of the measurement object and having good reproducibility.

[0030] A representative Raman spectrometer used in Raman spectroscopy is illustrated in Fig. 3. The Raman spectrometer 300 includes a laser irradiation unit 21, a bandpass filter 22, a Rayleigh cut filter 23, an objective lens 24, a sample stage 25, a confocal pinhole 26, a spectrometer slit 27, a diffraction grating 28, a detection unit 29, and a computer 30. The laser light 31a irradiated from the laser irradiation unit 21 is converted into laser light 31b of a specific wavelength by the bandpass filter 22, and is guided to the objective lens 24 by a reflecting member (not shown) and the Rayleigh cut filter 23, and then irradiated onto a measurement target 32 ​​set on the sample stage 25. The scattered light 31c scattered from the measurement target 32 ​​is collected by the objective lens 24, and Raman scattered light 31d is extracted through the Rayleigh cut filter 23. The Raman scattered light 31d passes through the confocal pinhole 26 and the slit 27, is separated by the diffraction grating 28, is detected as a Raman spectrum by the detector 29, and is subjected to data processing by the computer 30. In addition to the above configuration, the Raman spectrometer 10 may also include a configuration such as a control unit described in WO2019 / 117177 as necessary. The computer 30 includes a control unit, a data processing unit, and a calculation unit.

[0031] In the first embodiment, the plurality of fractionated liquids 8 obtained in the second step are used as the measurement object 32, which are placed on a Raman spectroscopic plate 33 (see FIG. 4) and dried as necessary. Next, the Raman spectroscopic plate 33 is set on the sample stage 25, and Raman spectroscopy is performed on the measurement object (the fractionated liquids or their dried products).

[0032] The number of measurements (number of samples) of the fractions to be subjected to Raman spectroscopy is not limited as long as it is more than one, and may be performed on all of the fractions collected in the second step, or may be performed on only a portion of the fractions. Preferably, two or more (preferably, three or more) fractions are selected from the group of fractions fractionated and collected within one peak in the chromatogram.

[0033] The drying of the separated liquid may be either natural drying or heat drying. The entire amount of the separated liquid may be dried, or a part of the separated liquid may be extracted and dried. Preferably, only a part of the separated liquid is extracted and subjected to Raman spectroscopy. Specifically, a small amount (e.g., 1 / 2 or less, preferably 1 / 5 or less, e.g., 1 / 100 or more) of the separated liquid is extracted using a splitter or the like, and this small amount of separated liquid is placed on a plate for Raman spectroscopy. This allows a dried product to be obtained in a short time, and the analysis can be made more efficient and shorter.

[0034] The plate for Raman spectroscopy is not limited, and examples thereof include a glass substrate, a stainless steel substrate, and a germanium substrate.

[0035] The third step obtains a Raman spectrum for each polymer compound contained in each fraction. By comparing these two or more Raman spectra, the details of the polymer compound can be obtained. Specifically, by collating the peak position (Raman shift) of the Raman spectrum with a known library, information on the monomer composition (e.g., molecular bonds, elements, molecular structure, etc.) can be obtained. Furthermore, by comparing the peak intensities, information on the monomer composition ratio (e.g., the relative amount of each monomer, the monomer composition ratio, etc.) can be obtained. In particular, focusing on a peak located at a desired Raman shift, the corresponding peaks in the Raman spectra measured for each fraction are compared. Then, if there is almost no change between the peak intensities, it is found that the amount of the monomer having the structure corresponding to the corresponding peak is constant. In other words, it can be determined that there is no molecular weight dependency of the polymer compound composition. On the other hand, if the peak intensities increase or decrease, it is found that the amount of the corresponding monomer increases or decreases accordingly. In other words, it can be determined that there is molecular weight dependency of the polymer compound composition.

[0036] In the first embodiment, the method includes a first step of separating a polymer compound using size exclusion chromatography, a second step of collecting the separated polymer compound at each predetermined elution time, and a third step of measuring the Raman spectrum of the collected polymer compound using Raman spectroscopy. Therefore, when analyzing the polymer compound, the details of the structure of the polymer compound can be easily analyzed. In particular, a method for easily analyzing the molecular weight distribution and the molecular weight dependency of the copolymer composition can be provided.

[0037] In addition to the present invention, other methods for analyzing the dependence of the monomer composition ratio on the molecular weight range include (1) an analysis method in which LC and Fourier transform infrared spectroscopy (FTIR) are performed in sequence, (2) a method in which LC and NMR are performed in sequence, and (3) a method in which pyrolysis gas chromatography and mass spectrometry (py-GC / MC) are performed in sequence. However, in the method (1), the fraction separated by LC in the FFIR must be sprayed onto a heated plate to evaporate the liquid components, and a rare germanium plate is required to perform high-sensitivity total reflection FTIR. This is disadvantageous in terms of availability and the ability to continuously perform a large amount of analysis. In the method (2), liquid helium or an isotope-substituted heavy solvent (heavy water, deuterated acetonitrile, etc.) must be used for high-sensitivity analysis. This is disadvantageous in that it is difficult to handle and the process is complicated. In the method (3), a pyrolysis process is essential, and it is necessary to use a nebulizer gas required for mass spectrometry and to operate in a high vacuum environment. This is disadvantageous in that the process becomes complicated.

[0038] In contrast, in the first embodiment, since Raman spectroscopy is adopted particularly in the second step, highly sensitive measurements are possible. In addition, since there are no restrictions on the material of the sample container such as a plate, a large amount of samples can be continuously measured. Furthermore, since no pyrolysis step or high vacuum environment is required, the measurement can be performed simply by placing the separated liquid on the plate, which enables simple analysis.

[0039] An analysis system 500 that enables the analysis method of the first embodiment includes an LC apparatus 100, a fractionation apparatus 200, and a Raman spectrometer 300, as shown in Fig. 4. The analysis apparatus may be an offline type in which (1) the LC apparatus 100-fractionation apparatus 200 and (2) the Raman spectrometer 300 are independent of each other, or an online type in which they are connected to each other by a tube that delivers the fractionated liquid. As shown in Fig. 5, (1) the LC apparatus 100-fractionation apparatus 200 and (2) the Raman spectrometer may be controlled by a computer 40. In this case, the computer 40 controls the computer 5 of the LC apparatus 100 and the computer 30 of the Raman spectrometer 300, and may also have the functions of the computer 5 and the computer 30.

[0040] 2. Aspects It will be appreciated by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0041] (Item 1) A method for analyzing a polymer compound according to one embodiment may include a first step of separating a polymer compound contained in a sample by size exclusion chromatography to obtain a chromatogram, a second step of fractionating an eluted component corresponding to one peak containing the polymer compound in the chromatogram into a plurality of fractions for each elution time, and a third step of measuring the Raman spectrum of the fractionated eluted component by Raman spectroscopy. This makes it possible to easily analyze the molecular weight distribution of the polymer compound and the molecular weight dependency of the polymer compound composition.

[0042] (Item 2) In the analysis method described in item 1, two or more Raman spectra measured in the third step may be compared. This makes it possible to analyze whether the polymer compounds of the compared Raman spectra have the same composition. In addition, since polymer compounds with different molecular weights are eluted at each elution time, the details of the polymer compound structure, particularly the molecular weight distribution and the molecular weight dependency of the polymer compound composition, can be easily analyzed.

[0043] (Item 3) In the analysis method according to item 1 or 2, the polymer compound may be a copolymer. This makes it possible to analyze a polymer compound in which a plurality of monomers are polymerized.

[0044] (Item 4) In the analysis method according to item 3, the copolymer may be a binary copolymer, a ternary copolymer, or a quaternary copolymer, which makes it possible to analyze polymer compounds having two, three, or four types of polymerized monomers.

[0045] (Item 5) An analytical system for polymer compounds according to one embodiment is an analytical system for carrying out the method according to any one of items 1 to 4, and may include a liquid chromatography device for separating polymer compounds contained in a sample by size exclusion chromatography to obtain a chromatogram, a fractionation device for fractionating an eluted component corresponding to one peak containing the polymer compounds in the chromatogram into a plurality of fractions for each elution time, and a Raman spectrometer for measuring the Raman spectrum of the fractionated eluted components. This makes it possible to easily analyze the molecular weight distribution of polymer compounds and the molecular weight dependency of the polymer compound composition. EXAMPLES

[0046] The present invention will now be described in detail with reference to examples, but the scope of the present invention is not limited to these examples.

[0047] <Example 1> A commercially available AS resin (acrylonitrile-styrene copolymer) was used as a sample. The liquid chromatography device and fractionation device shown in Figure 4 were used under the following conditions.

[0048] Equipment: Nexera (Shimadzu Corporation) Column: Shodex HK-404L (150 mm x 4.6 mm ID, 3.5 μm) Flow rate: 0.2mL / min Eluent:THF Sample concentration: 0.2% w / v (in THF) Column temperature: 40℃ Injection volume: 10μL Vial: SHIMADZU LabTotal for LC 1.5mL, Glass Detector (PDA): SPD-M30A at 260nm Splitter: 9:1 Spotting time: 20 seconds Spotting Plate: Hudson PL-PC-000040-P

[0049] As a result, the chromatogram in Figure 6 was obtained. At this time, the sample-containing eluent was fractionated at elution times of 4 minutes 20 to 40 seconds, 5 minutes 10 to 30 seconds, and 6 minutes 00 to 20 seconds, and these fractions were named fractions A, B, and C. The molecular weight of fraction A was approximately 200,000, fraction B was approximately 50,000, and fraction C was approximately 6,000.

[0050] Next, the Raman spectroscopy shown in Fig. 4 was carried out under the conditions described below for each of the fractionated solutions A to C to detect the Raman spectrum. The results are shown in Fig. 7.

[0051] Equipment: Microscopic Raman spectrometer XploRA PLUS (manufactured by Horiba, Ltd.) Excitation wavelength: 532 nm Exposure time: 10 seconds Number of times: 3 Number of grooves on diffraction grating: 300 lines / mm Confocal hole: 100μm Slit width: 100μm Objective lens: 100x Detector: Syncerity Laser power: 6mW

[0052] From FIG. 7, in each of the fractions A to C, the 1000 cm -1 The peak at 2400 cm originates from acrylonitrile. -1 The peaks around the peaks were almost constant. This shows that the AS resin has no molecular weight dependency of the copolymer composition. The lack of molecular weight dependency of the commercially available AS resin used was verified by a different method.

[0053] <Example 2> A block copolymer of 2-vinylpyridine and methyl methacrylate (VP-MM copolymer, monomer composition ratio VP:MM = 3:97) was used as a sample. Liquid chromatography was carried out using the obtained sample under the same conditions as in Example 1. However, the sample concentration was changed to 0.5% w / v.

[0054] As a result, the chromatogram in Figure 8 was obtained. At this time, the sample-containing eluent was fractionated near two peak tops and one valley in the chromatogram, i.e., at an elution time of 6 minutes 20 to 30 seconds, 6 minutes 55 to 7 minutes 5 seconds, and 7 minutes 20 to 30 seconds, and these fractions were named fractions D, E, and F. In terms of molecular weight, fraction D was about 80,000, fraction E was about 20,000, and fraction F was 7,000.

[0055] Next, Raman spectroscopy was carried out on each of the fractions D to F under the same conditions as in Example 1 to detect the Raman spectrum. The results are shown in FIG.

[0056] As shown in Figure 9, the pyridine-derived 1213cm -1 Peak and 1547-1607 cm -1 Peak at 3061 cm due to the benzene ring C-H bond -1 The peaks were not observed much in fraction D, but were prominent in fractions E to F. This indicates that the vinylpyridine component increases in the VP-MM copolymer in the low molecular weight region, and that the copolymer composition is molecular weight dependent. The molecular weight dependency of the VP-MM copolymer used was verified by a different method. [Explanation of symbols]

[0057] REFERENCE SIGNS LIST 1 pump 2 sample supply section 3 column 4 detection section 5 computer 6 eluent 7 sample 8 fractionated liquid 11 discharge nozzle 12 container moving body 13 container 21 laser irradiation section 22 band pass filter 23 Rayleigh cut filter 24 objective lens 25 sample stage 26 confocal pinhole 27 spectrometer slit 28 diffraction grating 29 detection section 30 computer 31a 31b laser light 31c scattered light 31d Raman scattered light 32 measurement object 33 plate 40 computer 100 LC device 200 fractionation device 300 Raman spectrometer 500 analysis system

Claims

1. A first step of separating polymer compounds contained in a sample using size exclusion chromatography to obtain a chromatogram; a second step of further fractionating an eluted component corresponding to one peak containing the polymer compound in the chromatogram into a plurality of fractions for each elution time; A third step of measuring the Raman spectrum of the separated eluted component by Raman spectroscopy; A method for analyzing a polymer compound, comprising:

2. The analytical method described in claim 1, wherein the monomer composition ratio based on the molecular weight distribution is measured by Raman spectra for each elution time for the same type of polymer compound corresponding to the one peak.

3. The analytical method according to claim 1 or 2, wherein two or more Raman spectra measured in the third step are compared.

4. The analytical method according to any one of claims 1 to 3, wherein the polymer compound is a copolymer.

5. The method of claim 4, wherein the copolymer is a copolymer, a terpolymer, or a tetrapolymer.

6. An analytical system for carrying out the method according to any one of claims 1 to 5, comprising: A liquid chromatography apparatus for separating polymer compounds contained in a sample by size exclusion chromatography and obtaining a chromatogram; a fractionation device for fractionating an eluted component corresponding to one peak containing the polymer compound in the chromatogram into a plurality of fractions for each elution time; a Raman spectrometer for measuring the Raman spectrum of the separated eluted component; An analytical system for a polymer compound comprising:

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