WO2004097395A1

WO2004097395A1 - Matrix for matrix aided laser desorption ionization mass analysis

Info

Publication number: WO2004097395A1
Application number: PCT/JP2004/005363
Authority: WO
Inventors: Hideaki Nakajima; Hiroshi Takigawa
Original assignee: Sumitomo Chemical Company, Limited
Priority date: 2003-04-30
Filing date: 2004-04-15
Publication date: 2004-11-11

Abstract

A matrix for MALDI mass analysis which comprises a compound represented by the formula (1): (1), wherein with respect to R1, R2, R3 and R4, two or more of them are an aryl group being optionally substituted with a halogen atom, a hydroxyl group, a sulfonic acid group, a carboxyl group, an alkyl group or an alkoxy group, and having 6 to 18 carbon atoms in total, one or less of them is a hydrogen atom, and the rest of them is an alkyl group being optionally substituted with a halogen atom, a hydroxyl group or a sulfonic acid group, and having 1 to 10 carbon atoms in total; each of R5, R6, Rai and Rbi is a hydrogen atom or an alkyl group; and n is an integer of 0 to 3 and i is an integer of 1 to n. The matrix is, in the MALDI mass analysis, capable of retaining a great signal intensity also after it is exposed under vacuum for a long time.

Description

Akira Matrix for matrix assisted laser desorption mass spectrometry

TECHNICAL FIELD The present invention relates to a matrix in a matrix-assisted laser desorption (hereinafter, referred to as MALDI) mass spectrometry.

Background art

Mass spectrometry is used to determine the molecular weight and structure of organic compounds.

You. In order to perform mass spectrometry measurements, it is necessary to ionize the sample field. One method of ionizing the sample is to irradiate the sample with a laser beam and instantaneously heat the sample. The MALDI method, which ionizes the molecules of the substance to be measured without decomposing it, has been widely used in recent years, especially for mass spectrometry using a polymer compound having a molecular weight of 500 or more as the substance to be measured. ing.

In general, in MA LDI mass spectrometry, a solution of the substance to be measured is mixed with a matrix solution and, if necessary, an ionization aid, applied on a sample table called a target, and the solvent is removed. The sample is removed, and the target with the sample attached is placed in a vacuum device. When the target is irradiated with the laser beam, the matrix changes the energy of the laser beam into heat energy and transmits it to the target substance, thereby ionizing the target substance. Thus, in MALDI mass spectrometry, a matrix is used to ionize the substance to be measured.

Conventionally, compounds that can be used as a matrix include 2,5-dihydroxybenzoic acid, disulanol, 2- (4-hydroxyphenylazo) benzoic acid (HAB A) (for example, “Bunseki”, In April 1996, see The Japan Society for Analytical Chemistry, p. 253-262, and 1,4-diphenylbutadiene have been proposed (see, for example, — See 1 5 3 8 4 2 gazette.

Here, in general, in actual measurement, when a target is taken in and out of the mass spectrometer, which is kept in a high vacuum, from outside the device at atmospheric pressure, the degree of vacuum decreases each time. However, it takes time to reach the degree of vacuum at which measurement can be performed. Therefore, for example, 100 samples are placed on one target, and the target is placed in the device. An operation of sequentially measuring each sample is performed. It usually takes one hour or more to complete the measurement of 100 samples placed on one target.Therefore, the last sample in the measurement order is kept under vacuum until the measurement is performed. It is placed in However, using a conventional matrix, the intensity of the signal obtained decreases with the lapse of time since the target was placed in the device, and it can be obtained when the elapsed time is longer than 30 minutes. There is a problem that the signal intensity is not sufficient, and there has been a demand for a matrix that can maintain a strong signal intensity even after being subjected to a vacuum for a long period of time ^ I.

Disclosure of the invention

An object of the present invention is to provide a matrix capable of maintaining a strong signal intensity even after being placed under vacuum for a long time in MALDI mass spectrometry.

In order to solve the above-mentioned problems, the present inventor has continued intensive studies on the matrix used for MA LDI mass spectrometry, and has found that at least three substituents are present at the end of a hydrocarbon chain having two or more double bonds. The present inventors have found that a compound represented by a specific formula to which is bonded becomes a matrix capable of maintaining a strong signal intensity even after being placed in a vacuum for a long time, and completed the present invention.

That is, the present invention provides the following formula (1)

(1)

(Wherein, R 1, R 2, R 3, and R 4 may be the same or different, and at least two of them each have a total carbon number of 6 to 18 and are a halogen atom, a hydroxyl group, a sulfo An aryl group which may be substituted with an acid group, a carboxyl group, an alkyl group, or an alkoxy group;

(i) When two of Rl, R2, R3, and R4 are the aryl groups, the remaining two independently have a total carbon number of 1 to 10 and include a halogen atom, a hydroxyl group, and a sulfone. The force which is an alkyl group optionally substituted by an acid group, one of the remaining two is a hydrogen atom, and the other one is the above-mentioned alkyl group.

(ii) When three of Rl, R2, R3, and R4 are the aryl groups, the other one is a hydrogen atom or the alkyl group.

(ii) All of Rl, R2, R3, and R4 are the aryl groups.

R 5, R 6, R a or R bi may be the same or different and are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and n is 0 Is an integer from 3 to 3, and i is an integer from 1 to n. A matrix for matrix-assisted laser desorption mass spectrometry, comprising a compound represented by the formula: The present invention also provides a composition for matrix-assisted laser desorption mass spectrometry comprising the matrix described above. The present invention also provides a matrix-assisted laser desorption mass spectrometry method using the matrix described above. Further, the present invention provides a method for quality control of a synthetic polymer, characterized by using the matrix-assisted laser desorption mass spectrometry method described above.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a chart showing the results of Example 1. In the case where 1,1,4,4-tetraphenyl-1,3-butadiene was used as the matrix, the signal of polystyrene 1 hour after the sample installation was used. The measurement results are shown. The scale of the vertical axis is arbitrary.

Figure 2 is a chart showing the results of Comparative Example 1. The signal of polystyrene 1 hour after the sample was set when trans.trans, 1,4-diphenyl-1,3-butadiene was used as the matrix. 2 shows the measurement results. The scale of the vertical axis is an arbitrary unit, but the same scale as in Fig. 1.

Fig. 3 is a chart showing the results of Comparative Example 2. Measurement of polystyrene signals one hour after sample installation when dithranol was used as the matrix. The results are shown. The scale of the vertical axis is an arbitrary unit, but is the same scale as in Fig. 1. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail.

The matrix of the present invention has the formula (1)

And a compound represented by In the formula (1), R1, R2, R3, and R4 may be the same or different from each other, and at least two of them have a total carbon number of 6 to 18 and are a halogen atom, a hydroxyl group, a sulfonic acid group, An aryl group which may be substituted with a carboxyl group, an alkyl group, or an alkoxy group;

(i) When two of Rl, R2, R3, and R4 are the above aryl groups, the remaining two are each independently substituted with a halogen atom, a hydroxyl group, and a sulfonate group having a total carbon number of 1 to 10. However, one of the remaining two is a hydrogen atom, and the other one is the alkyl group.

(ii) When three of Rl, R2, R3 and R4 are the above aryl groups, the other one is a hydrogen atom or the above alkyl group.

(iiii) Rl, R2, R3, and R4 all represent the aryl group.

Is one of At this time, R1 and R2, and further R3 and R4, may be linked by a carbon chain.

In the formula (1), Rl, R2, R3, and R4 may be the same or different from each other, and at least two of them have a total of 6 to 18 carbon atoms each and have a halogen atom, a hydroxyl group, a sulfonic acid group, A aryl group which may be substituted with a carboxyl group, an alkyl group, or an alkoxy group;

(i) When two of Rl, R2, R3, and R4 are the aryl groups, the remaining Two are each independently an alkyl group having a total carbon number of 1 to 10 and which may be substituted by a halogen atom, a hydroxyl group, or a sulfonate group; one of the remaining two is a hydrogen atom, The other one is the aforementioned alkyl group.

(iiii) Rl, R2, R3, and R4 all represent the aryl group.

In MALD I mass spectrometry, a compound that can maintain a strong signal intensity even after being placed in vacuum for a long time. In the formula (1), even if only two of R1, R2, R3, and R4 are the aryl groups, a compound in which the remaining two are hydrogen atoms does not form a matrix of the present invention. Of the Rl, R2, R3, and R4 forces of formula (1), at least three of them have a total number of carbon atoms of 6 to 18, each of which is a halogen atom, hydroxyl group, sulfonic group, carboxyl group, alkyl group, or alkoxy group. An aryl group which may be substituted,

(ii) When three of Rl, R2, R3, and R4 are the above aryl groups, the remaining one has 1 total carbon number and is 10 and is substituted with a halogen atom, a hydroxyl group, or a sulfonic acid group. Or an alkyl or hydrogen atom which may be substituted.

(ii) All of Rl, R2, R3, and R4 are the aryl groups.

Is preferred.

Examples of the aryl group which may be substituted with a halogen atom, a hydroxyl group, a sulfonic acid group, an alkyl group, or an alkoxy group include a phenyl group, a 1-chlorophenyl group, a 2-chlorophenyl group, and a 3-chlorophenyl group. Phenyl group, 1-bromophenyl group, 2-bromophenyl group, 3-bromophenyl group, 1-phenololenophenyl group, 2-phenylolephenyl group, 3-fluorophenyl group, 1-hydroxyphenyl group Group, 2-hydroxyphenyl group, 3-hydroxyphenyl group, 1-sulfonylphenyl group, 2-sulfoninolepheninole group, 3-snolehoninolepheninole group, 1-methinolepheninole group, 2-methylphenyl Group, 3-methylphenyl group, 1-ethylphenyl group, 2-ethylphenyl group, 3-ethylphenyl group, 1-n-propynolepheninole group, 2-n Pro Pirufueniru group, 3- n-propyl-phenylalanine group, 1 one i one propyl phenylpropyl group, 2-i-propylphenyl group, 3-i-propylphenyl group, 1-n-butylphenylinole group, 2-n-butynolephenyl group, 3-n-butynolephenyl group, 11 sec-butylphenyl 2-, 2-sec-butylphenyl, 3-sec-butinophenyl, 1-t-butylphenyl, 2-t-butylphenyl, 3-t-butylphenyl, 1-methoxyphenyl Group, 2-methoxyphenyl group, 3-methoxyphenyl group, 1-ethoxyphenyl group, 2-ethoxyphenyl group, 3-ethoxyphenyl group, 1-n-propoxyphenyl group, 2- n-propoxyphenyl group,

3-n-propoxyphenyl group, 1_i-propoxyphenyl group, 2-i-propoxyphenyl group, 3-i-propoxyphenyl group, 1-n-butoxyphenyl group, 2_n -Butoxyphenyl, 3-n-butoxyphenyl, 1-sec-butoxyphenyl, 2-sec-butoxyphenyl, 3-sec-butoxyphenyl, 1-t-butoxyphenyl, 2-t-butoxyphenyl, 3-t —Butoxyphenyl group, 1,2-dichlorophenyl group, 1,3-dichlorophenyl group, 2,3-dichlorophenyl group, 1,2-dibromophenyl group, 1,3-dibromophenyl group, 2 1,3-dibromopheninole group, 1,2-diphneolelophenyl group, 1,3-difluorophenyl group, 2,3-difluorophenyl group, 1,2 disulfonylpheninole group, 1,31 Snorephonylphenyl group, 2,3-dishonolephonylphenyl group, 1,2-dihydroxyphenyl group, 1,3-dihydroxyphenyl group, 2,3-dihydroxyphenyl group, 1,2-dimethylphenyl group, 1 , 3-Dimethylphenyl group, 2,3-Dimethylphenyl group, 1,2-Getylphenyl group, 1,3-Getylphenyl group, 2,3-Jethylphenyl group, 1,2-Dimethoxyphenyl group, 1 , 3-Dimethoxyphenyl group, 2,3-Dimethoxyphenyl group, 1,2-Diethoxyphenyl group, 1,3-Diethoxyphenyl group, 2,3-Diethoxyphenyl group, 1-Naphthyl group And 2-naphthyl group, 1-anthraniyl group, 2-anthranyl group, 3-anthranyl group and the like.

Examples of the alkyl group which may be substituted with a halogen atom, a hydroxyl group or a sulfonic acid group include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a sec-butyl group and a t-butyl group Group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, chloromethyl group, bromomethyl group, fluoromethyl group, 1-chloroethynole group, 2-chloroethynole group, 1-bromoethynole group, 2-bromoethyl group, 1-fluoroethyl group, 2-fluoroethyl group, 1-chloro-1-n-propyl group, 2-chloro-n-propyl group, 3-chloro n-propyl group, 1-promo n-propyl group, 2-promo n-propyl group, 3-bromo-n-propyl group, 1-fluoro-i-propyl group, 2-fluoro-i-propyl group, Hydroxymethyl group, hydroxyethyl group, 1-hydroxy-1-η-propyl group, 2-hydroxy η-propyl group, 3-hydroxy_η-propyl group, 1-hydroxy-1-i-propyl group, 2-hydroxy-1 i-Propyl group, sulfomethyl group, 1-sulphoechinole group, 2-snolejochinole group, 1-snolejo n-propynole group, 2-snolejo-n-propyl group, 3— Sulfo one n- propyl group, 1 one sulfo one i- propyl group, and an 2 Suruho i one propyl group.

Each of R1, R2, R3, and R4 is preferably a phenyl group or an alkyl-substituted phenyl group, and more preferably a phenyl group.

R5, R6, Rai, and Rbi are each a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. Here, when n is 0, there is no repeating unit shown in parentheses in equation (1), so R & i and Rbi do not exist, and when n is an integer of 1 or more, (1) The i-th substituent R a or Rbi in the unit shown in parentheses in the formula is independent of each other. The compound represented by the formula (1) has two or more double bonds in the molecule except for a six-membered ring.

Examples of the alkyl group having 1 carbon atom and 10 alkyl groups include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butylinole group, a sec-butyl group, a t-butyl group, an n-pentyl group, 2-pentyl group, 3-pentyl group, 2-methyl-1-butyl group, 3-methyl-1-butyl group, 2-methyl-1-butyl group, 3-methyl-2-butyl group 2,2-dimethylpropyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl, n-decyl group and the like.

R5, R6, Ra _is R bi good Mashiku those are all hydrogen atom or a methyl group, those more preferably all hydrogen atoms. In the case where the compound represented by the formula (1) has a structural isomer due to a double bond site, the compound represented by the formula (1) is easily absorbed by laser energy. (A bond in which all bonds in the double bond except for the 6-membered ring are in trans form). The compound represented by the formula (1) preferably has a size that does not hinder the detection of sample molecules, and preferably has a molecular weight of 100,000 or less.

Examples of the compound represented by the formula (1) include compounds represented by the following formulas (2).

(2)

01

C9CS00 / l700Zdf / X3d Among the compounds represented by the formula (1), 1,1,4,4-tetraphenyl-1,3-butadiene (formula (3)) and 1,4-triphenyl-1,3-butadiene (formula (3) 4)) is most preferred.

(3)

The matrix is preferably uniformly mixed with the substance to be measured on a metal sample table called a target. In particular, when the substance to be measured is a high-molecular compound, to uniformly mix the matrix and the substance to be measured, 1 og P, which is the water Z-octanol distribution ratio of the matrix of the present invention, is set to 1 og P of the substance to be measured. It is desirable that the difference is close to 1 og P of the monomer unit. Specifically, it is desirable that the difference between 1 og P of the matrix and 1 og P of the monomer unit is within 10 or less. For example, to analyze polystyrene with 1 og P of styrene monomer being 3.2 or polymethyl methacrylate with 1 og P of methyl methacrylate being 1.2, the compound of formula (1) For example, 1,1,4,4-tetrafluoro-1,3-butadiene having a log P of 7.9 (molecular weight: 358) is suitable.

1 og P is the distribution ratio of water Z octanol, which is known in the art.For example, OECD G. UIDEL I NE FOR THE TEST I NG OF CHEMI CALS (Ad opted by the council on 27th July 1995) It is described, but is not limited to this, and is also required by computer software C 1 og P (trade name, manufactured by Bio Byte, USA). For example, logP of 1,1,4,1-triphenyl-1,3-butadiene Is 6.5.

The purity of the compound used as the matrix is preferably 90% or more. In particular, when a high molecular weight sample is measured, it is preferable that the component having a molecular weight of 100 or more is 5% by weight or less so that the sample can be clearly distinguished from the sample.

The sample can contain a substance to be measured and a matrix, and a metal salt such as silver trifluoroacetate, copper nitrate, sodium chloride, and potassium chloride, an ammonium salt, and an organic salt as an ionization initiator.

The method for preparing a mixture of the substance to be measured and the matrix on the target is not particularly limited.For example, the substance to be measured, the matrix, and the ionization initiator are each prepared in advance as a solution. In advance, after mixing these, the mixture can be attached to a target with a micropiter or a microsyringe, and then the solvent can be distilled off. At this time, the surface of the sample formed on the target is preferably uniform.

The quantitative ratio of the substance to be measured and the matrix is not particularly limited, but the sample: matrix = 1: 1 molar ratio to 1: 1000 molar ratio is preferable. More preferably, the molar ratio is from 1: 2 to 1: 500. The substance to be measured is not particularly limited, but considering that the ionization of the matrix itself does not disturb the spectrum, when the substance to be measured has a single molecular weight, The molecular weight is preferably at least 500, more preferably at least 100. When the substance to be measured has a molecular weight distribution, the weight average molecular weight is preferably 500 or more in terms of polystyrene measured by size exclusion chromatography (GPC), and the weight average molecular weight is 100 or more. More preferably, it is a compound.

Since such a matrix for MA LDI mass spectrometry of the present invention can maintain a strong signal intensity even after being placed in a vacuum for a long period of time, by using the matrix of the present invention, Mass spectrometry can be performed efficiently by installing a large number of samples. Therefore, MALDI mass spectrometry using the matrix of the present invention can be suitably used for quality control of synthetic polymers. To perform quality control using MA LDI mass spectrometry using the matrix of the present invention, A sample is randomly sampled from the produced synthetic polymer, a solution of the substance to be measured is mixed with a matrix solution and, if necessary, an ionization aid, and applied on a target to remove the solvent, thereby obtaining a sample. Data is obtained by placing the target on the MA LDI mass spectrometer and performing mass spectrometry on each sample in turn. From the signal intensity data for each mZ z, we estimate the standard deviation of the population using statistical quality control methods, estimate the average value of the population, etc. A test can be performed. In addition, a control chart can be created to manage the process so that it is kept stable.

The signal intensity maintenance performance under vacuum can be evaluated by the following method. After the target with a fixed amount of sample mixed with a fixed amount of matrix is inserted into the MA LDI mass spectrometer, it is left under vacuum for a certain period of time, and then the laser irradiation energy and the number of laser irradiations on the target are measured. The signal intensity of the mass spectrum of the sample obtained when the measurement was performed at a constant level was high, but the signal intensity maintenance performance under vacuum was high. At this time, the signal maintenance performance is high, and for matrixes, the signal intensity of the mass spectrum obtained when the target is measured immediately after insertion into the MALDI mass spectrometer is high, improving the measurement sensitivity. You can also.

In MALDI mass spectrometry, ions generated from a sample by laser irradiation are detected separately. A time-of-flight mass spectrometer is a device that separates and detects these ions, and is a device suitable for using a polymer compound as a substance to be measured. By combining with a time-of-flight mass spectrometer, it is possible to measure a high molecular compound having an extremely large molecular weight, and it can be suitably used for measuring a molecular weight distribution of a biopolymer or a synthetic polymer.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

Example 1

Using 1,1,4,4-tetraphenyl-1,3-butadiene (PFALTZ & BAUER Co., Ltd.) as matrix, Tosoh Corporation polystyrene standard Article A—250.000 (molecular weight 250.000) was used as a substance to be measured, and silver trifluoroacetate was used as an ionization aid. Matrix, samples, ionization aid mixing ratio, J. Am. S oc. Ma ss S pectr om. 1 9 9 6, 7, in accordance with 1 1 one 24, matrix 2x 1 0 one ¹ M, of the analyte A THF solution prepared at a concentration of 3.3 × 10 ⁴ M and silver trifluoroacetate at a concentration of 4.5 × 10— ° M was mixed at a volume ratio of 5: 1: 1. After μ 1 was impregnated and the solvent was distilled off, the target was inserted into a time-of-flight mass spectrometer equipped with a Ref 1 e χΙΠ type MALD I ion source manufactured by Bunoreka Danoretonitas. After the target was inserted into the mass spectrometer, it was left under vacuum for 60 minutes, and then the measurement was performed in the positive ionization mode with an acceleration voltage of 26.5 kV and an integrated laser shot of 200 times. . In the evaluation of the signal strength maintaining performance, a sign nanore strength of mZz = 2561, which indicates a styrene monomer trimer in the obtained mass spectrum, was used.

The signal intensity indicating the performance of maintaining the signal intensity when the matrix of Example 1 was used was 193232 counts.

Comparative Example 1

About the matrix used in Example 1 1,1,4,4-tetraphenyl-1,3-butadiene is trans-, trans-1,4-diphenyl-1,3-butadiene (Reagent from Lancaster) The measurement was performed under the same conditions as in Example 1 except that the measurement was changed to.

The signal intensity showing the performance of maintaining the signal intensity when the matrix of Comparative Example 1 was used was 248 counts.

Comparative Example 2

For the matrix used in Example 1, the measurement was carried out under the same conditions as in Example 1 except that 1,1,4,4-tetraphenyl_13-butadiene was changed to disulanol (a reagent manufactured by Aldrich).

The signal intensity showing the performance of maintaining the signal intensity when the matrix of Comparative Example 1 was used was 249 counts.

Table 1 summarizes the results of Example 1 and Comparative Examples 1 and 2. 1, 1, 4, 4- When tetraphenyl-1,3-butadiene is used for matrix, even if the sample and matrix mixture are left under vacuum for 60 minutes, a very strong signal is obtained as compared to the conventional matrix used in Comparative Examples 1 and 2. Since the strength was obtained, it was found that the matrix of Example 1 was excellent in maintaining the signal strength under vacuum. table 1

Industrial applicability

The matrix of the present invention is excellent in that it maintains a high signal intensity even under a high vacuum for a long time. Therefore, the MALDI mass spectrometry method using the matrix of the present invention can be used to measure many substances to be measured at once, and the efficiency of the measurement can be increased, which is extremely industrially important.

Claims

The scope of the claims

(In the formula, Rl, R2, R3, and R4 may be the same or different, and at least two of them each have a total carbon number of 6 to 18 and are a halogen atom, a hydroxyl group, a sulfonate group, a carboxyl group, An aryl group which may be substituted with an alkyl group or an alkoxy group,

(i) When two of Rl, R2, R3, and R4 are the above aryl groups, the remaining two are each independently substituted with a halogen atom, a hydroxyl group, and a sulfonate group having 1 to 10 total carbon atoms. Or one of the remaining two is a hydrogen atom, and the remaining Λ are the above-mentioned alkyl groups.

(ii) All of Rl, R2, R3, and R4 are the aryl groups.

R5, R6, R ai, and R bi may be the same or different from each other, and are each independently a hydrogen atom or an alkyl group having 1 carbon atom and a total of 10 carbon atoms, and n is 0 or more. Is an integer less than or equal to 3, and i is an integer from 1 to n. A matrix for matrix-assisted laser desorption mass spectrometry, comprising a compound represented by:

2. In formula (1), Rl, R2, R3, and R4 are each a halogen atom, a hydroxyl group, a sulfonic acid group, a carboxyl group, an alkyl group, or an alkoxy group in which at least three have a total carbon number of 6 to 18, and 2. The matrix according to claim 1, which is an aryl group which may be substituted.

3. The matrix according to claim 1, wherein R5, R6 and Ra or Rbi in the formula (1) are each a hydrogen atom or a methyl group.

4. Rl, R2, R3, and R4 in Formula (1) have at least three of which have a total carbon number of 6 to 18 and are substituted with a halogen atom, a hydroxyl group, a sulfonic acid group, an alkyl group, or an alkoxy group. 4. The matrix according to claim 2, wherein the aryl group is an aryl group, R5 and R6 are each a hydrogen atom, and n is 0.

5. A composition for matrix-assisted laser desorption mass spectrometry, comprising the matrix according to any one of claims 1 to 4.

6. A matrix-assisted laser desorption mass spectrometry method using the matrix according to any one of claims 1 to 4.

7. A method for quality control of a synthetic polymer, using the matrix-assisted laser desorption mass spectrometry method according to claim 6.