JP3615480B2 - Sample analysis method - Google Patents

Description

【００４２】
【表２】

【００４３】
表１から明らかなように、試料とした粘着テープＡの粘着剤の第１の合算マススペクトルは、データベースの３種の粘着テープの粘着剤（データライブラリ＃１，＃２，＃３）のいずれとも類似した結果を示し、同定が困難である。
【００４４】
しかし、表２から、試料とした粘着テープの粘着剤の第２の合算マススペクトルは、データライブラリ＃５，＃６に比較して、データライブラリ＃４と特に高い一致率を示し、試料とした粘着テープの粘着剤が粘着テープＡの粘着剤と同定できることが明らかである。
【００４５】
前記各実施形態は、粘着テープの粘着剤を例として説明しているが、本発明の分析方法は、加工食品、香料、麻薬、薬剤等、主要成分が同一である複数の高分子試料の異同識別、同定に用いることができる。また、前記各実施形態は、高分子試料について説明しているが、本発明の分析方法は、高分子試料以外の試料の異同識別、同定にも用いることができる。
【図面の簡単な説明】
【図１】本発明の分析方法に使用する装置の一実施形態を示すシステム構成図。
【図２】図１示のパーソナルコンピュータの構成を示すブロック図。
【図３】図１示の装置により得られた高分子試料の熱分解ガスクロマトグラム（パイログラム）。
【図４】図３示の全てのピークに対応する第１の合算マススペクトル。
【図５】図３の拡大図。
【図６】図５の主要成分のピークを除く残余のピークに対応する第２の合算マススペクトル。
【符号の説明】
２…熱分解装置、 ４…キャピラリーカラム、 ５…質量分析計、 ６…パーソナルコンピュータ。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for analyzing a plurality of samples having the same main component.
[0002]
[Prior art]
In recent years, in criminal investigations and the like, it is performed to analyze differences between a plurality of polymer samples having the same main component. For example, an adhesive tape in which an adhesive is applied to the surface of a tape such as kraft paper, cloth, or resin film is used for packaging and the like, and the manufacturer can be specified by analyzing the difference between the adhesives. This is the same in that the pressure-sensitive adhesive contains natural rubber as a main component. However, additives such as a tackifier resin, a softening agent, an antioxidant for antioxidants, and the like added to the rubber by the manufacturer. It is due to being different. Also, in the case of narcotics and the like, the main components are the same, but the produced region may be identified by the difference in trace components.
[0003]
Conventionally, as a method for analyzing a polymer sample such as a resin, data obtained by a method (Py-GC / MS method) combining pyrolysis gas chromatography (Py-GC method) and mass spectrometry is used as a database. A method of comparing and identifying a known polymer sample stored in the database that matches the data is known. However, even if the Py-GC method, the Py-GC / MS method, or the like is used, it takes time and high skill and experience to identify the polymer sample.
[0004]
Therefore, the applicant of the present application has already proposed a technique for improving the Py-GC / MS method and easily identifying a polymer sample in a short time (see Japanese Patent Application Laid-Open No. 2000-35422).
[0005]
In the method described in the above publication, first, a mixture of pyrolysis products obtained by introducing the polymer sample into a pyrolysis furnace and pyrolyzing instantaneously or by heating at elevated temperature is converted into each pyrolysis product using a capillary column. The separated pyrolysis product is detected by a mass spectrometer such as a magnetic field type mass spectrometer or a quadrupole mass spectrometer. In the mass spectrometer, the gaseous pyrolysis product separated by the capillary column is irradiated with electrons every predetermined time, for example, every 0.008 minutes, to generate molecular ions or fragment ions, and a predetermined range. The molecular ions and fragment ions corresponding to the mass / charge (m / z) ratio are continuously scanned. As a result, in the mass spectrometer, each ion intensity corresponding to the mass / charge (m / z) ratio in the predetermined range is obtained as a set of detection data for each predetermined time.
[0006]
Next, the ion intensity obtained by scanning at the predetermined time is set as one set, and is added for each set to obtain a total ion intensity. The total ion intensity is arranged in the detection order, and the peak of each total ion intensity is set. When tied, a pyrolysis gas chromatogram (pyrogram) indicating the intensity of ions detected corresponding to the retention time is obtained. Therefore, next, for all the peaks included in the pyrogram, the respective ion intensities are summed for each mass / charge (m / z) ratio of each molecular ion and fragment ion, and these are arranged in order of mass. To create a combined mass spectrum.
[0007]
Then, the polymer sample is identified by comparing the summed mass spectrum with a database constructed by collecting summed mass spectra created in the same manner for known polymer samples.
[0008]
The total mass spectrum can be considered as a mass spectrum detected by immediately applying a mixture of pyrolysis products obtained by pyrolyzing the polymer sample to a mass spectrometer without applying to a capillary column. Therefore, according to the method described in the above publication, since only one combined mass spectrum corresponds to one polymer sample, the polymer sample can be easily identified in a short time.
[0009]
Further, since the mixture of pyrolysis products obtained by pyrolyzing the polymer sample is the same regardless of the separation conditions in the Py-GC method, the total mass spectrum is different even when the separation conditions are different. The polymer sample can be easily identified.
[0010]
However, the combined mass spectrum used in the method for identifying an unknown polymer sample described in the above publication is difficult to distinguish between differences when comparing a plurality of polymer samples having the same main component.
[0011]
[Problems to be solved by the invention]
In view of the circumstances described above, an object of the present invention is to provide an analysis method that can easily identify differences between a plurality of samples having the same main component.
[0012]
[Means for Solving the Problems]
In order to achieve such an object, the sample analysis method of the present invention includes a step of separating each sample into individual contained components using a chromatographic apparatus, with respect to a plurality of samples having the same main component. Detects the intensity of molecular ions and fragment ions generated by ionizing each contained component of each sample every predetermined time to obtain detection data for each sample, and also detects each sample obtained by detection at each predetermined time Chromatograms of each sample are created by connecting the vertices of a histogram formed by adding the detection data for each set to obtain the total ion intensity, and arranging the total ion intensity in the order of detection. And adding the detection data included in the total ion intensity corresponding to each peak of the chromatogram for each ion of the same mass, Creating a first summed mass spectrum of each sample in which the summed data is arranged in the order of mass of the molecular ions and fragment ions, and the first summed data of each sample. The step of comparing the differences in mass spectra with each other and the total corresponding to each peak smaller than the peak of the main component of the chromatogram for each sample when the first combined mass spectrum of each sample is recognized as the same The detection data included in the ion intensity is added up for each ion of the same mass to obtain the second combined data of the intensity of the molecular ion and the fragment ion, and the combined data is arranged in the order of the mass of the molecular ion and the fragment ion Comparing the step of creating the second combined mass spectrum of each sample with the difference of the second combined mass spectrum of each sample Characterized in that comprising the that step.
[0013]
According to the analysis method of the present invention, first, each of a plurality of samples having the same main component is separated into individual components using a chromatograph such as a liquid chromatograph or a gas chromatograph, The first combined mass spectrum is created from the total ion intensity corresponding to all the peaks of the chromatogram by the method described in JP 2000-35422 A, and the difference between the first combined mass spectra is mutually determined. Compare. However, when the main components are the same, it is difficult to identify the difference from the first combined mass spectrum. This is presumably because the ratio of the ion intensity derived from the main component is higher than the ion intensity of the molecular ions and fragment ions of the entire sample in the first combined mass spectrum.
[0014]
Therefore, when the first combined mass spectrum is recognized to be the same, each peak smaller than the peak of the main component of the chromatogram, that is, the total ion corresponding to the remaining peak excluding the peak of the main component A second combined mass spectrum is created from the intensity, and the differences in the second combined mass spectrum are compared with each other. The main component may be plural.
[0015]
By doing so, the ionic strength of molecular ions and fragment ions contained in the peak of the main component is excluded, so ions are generated by molecular ions and fragment ions contained in the remaining peaks excluding the peak of the main component. The difference in intensity becomes remarkable, and the difference between the samples can be easily identified.
[0016]
The second total mass spectrum of the sample is further compared with a database constructed by collecting the total mass spectra created by the method described in JP 2000-35422 A for a plurality of known samples, Each sample may be identified by searching for a combined mass spectrum of known samples with a high percentage that matches the second combined mass spectrum of the sample. By doing in this way, the said difference can be confirmed with the said database.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. FIG. 1 is a system configuration diagram showing an embodiment of an apparatus used in the analysis method of the present invention, and FIG. 2 is a block diagram showing the configuration of the personal computer shown in FIG. 3 is a pyrolysis gas chromatogram (pyrogram) of the polymer sample obtained by the apparatus shown in FIG. 1, and FIG. 4 is a first combined mass spectrum corresponding to all the peaks shown in FIG. 5 is an enlarged view of FIG. 3, and FIG. 6 is a second combined mass spectrum corresponding to the remaining peaks excluding the peaks of the main components of FIG.
[0018]
As shown in FIG. 1, the unknown sample retrieval apparatus of the present embodiment includes a pyrolysis apparatus 2 including a pyrolysis furnace 1, a capillary column 4 connected to the pyrolysis apparatus 2 via an inlet 3, and a capillary column 4. From a connected mass spectrometer 5, a personal computer (hereinafter abbreviated as a personal computer) 6 capable of inputting detection data obtained by the mass spectrometer 5, and a printer 7 serving as an output means connected to the personal computer 6. Become.
[0019]
The thermal decomposition apparatus 2 instantaneously thermally decomposes the sample introduced from the sample introduction unit 8 through the sample cup 9 in the thermal decomposition furnace 1 to generate a mixture of thermal decomposition products composed of a plurality of gaseous organic compounds. Let The pyrolysis product is guided to the capillary column 4 through the inlet 3 by a carrier gas introduced from an inlet (not shown).
[0020]
The capillary column 4 is accommodated in a thermostatic chamber 11 controlled by a temperature controller 10, and the temperature of the thermostatic chamber 11 is raised from a low temperature to a high temperature to raise the mixture from a low boiling point compound to a high boiling point compound. In the order of the compounds, each pyrolysis product is separated and guided to the mass spectrometer 5. As the capillary column 4, a fused silica capillary column made of fused silica or a metal capillary column made of metal such as stainless steel can be used.
[0021]
The mass spectrometer 5 generates molecular ions by irradiating the pyrolysis product, which is a gaseous organic compound introduced from the capillary column 4, with electrons every predetermined time, and at the position unique to the organic compound. The bond is cleaved to generate fragment ions, and by scanning molecular ions and fragment ions corresponding to a predetermined range of mass / charge (m / z) ratio, the ionic strength of each ion is detected, and the predetermined time One set of ion intensity detection data is obtained for each scan.
[0022]
The mass spectrometer 5 shown in FIG. 1 is a quadrupole mass spectrometer, and an electric field is formed by applying a high frequency voltage to the four electrodes 12, and ions are surrounded by the four electrodes 12. Upon entering, only ions having a specific mass / charge ratio reach a detector (not shown) due to the interaction between the ions and the electric field. When the ions reach the detector, they discharge and generate a current. By measuring the current, detection data indicating the relative intensity of each mass of the ions can be obtained. The detection data is input to the personal computer 6 in the form of an electric signal. In the apparatus shown in FIG. 1, a quadrupole mass spectrometer is used as the mass spectrometer 5, but a magnetic field type mass spectrometer can also be used.
[0023]
The personal computer 6 includes a personal computer main body 13 and a display 14 as shown in FIGS. The personal computer main body 13 includes a main control unit 15 including a CPU, a RAM, a ROM, and the like, a pyrogram creation unit 16, a summation processing unit 17, a data storage unit 18, a search processing unit 19, and an output processing unit 20.
[0024]
The personal computer 6 controls the pyrogram creation unit 16, the summation processing unit 17, the data storage unit 18, the search processing unit 19, and the output processing unit 20 according to the processing procedure stored and held in advance in the main control unit 15. The processing procedure may be read and stored in the main control unit 15 in advance, and what is recorded in advance on a recording medium such as a flexible disk or a CD-ROM as application software processed by the personal computer 6 It may be read from the recording medium into the main control unit 15 and stored.
[0025]
The data storage unit 18 of the personal computer 6 stores the total mass spectrum collected for a plurality of known polymer samples as a database, and the database is read and stored in the data storage unit 18 in advance. Alternatively, what is recorded in advance on a recording medium such as a flexible disk or a CD-ROM may be read from the recording medium into the data storage unit 18 and stored therein.
[0026]
Next, the unknown sample search method of this embodiment using the apparatus shown in FIGS. 1 and 2 will be described.
[0027]
In this embodiment, the case where the difference is analyzed about the adhesive of two types of adhesive tapes A and B is demonstrated as an example. First, the same type of pressure-sensitive adhesive tape was attached to each other and then peeled off, and the pressure-sensitive adhesive layer to be peeled was scraped with tweezers to obtain about 1 mg.
[0028]
Next, about 0.1 mg of the adhesive of the adhesive tapes A and B collected as described above is put in the sample cup 9, and the thermal decomposition apparatus 2 (heating furnace type thermal decomposition manufactured by Frontier Laboratories, Inc.) shown in FIG. Equipment, product name: double shot pyrolyzer, model PY2020D) is introduced into the pyrolysis furnace 1 from the sample inlet 8 and heated to a pyrolysis temperature of 600 ° C. in the pyrolysis furnace 1 for instant pyrolysis. To do. Then, 1/50 of the mixture of pyrolysis products formed of the gaseous organic compound is divided at the inlet 3, and the carrier gas (inlet pressure: 0.8 kg / cm ² ) is passed through the inlet 3. It injects into the capillary column 4 (The metal capillary column by a Frontier Laboratories, brand name: UltraALLOY-5). The capillary column 4 is made of stainless steel having a length of 30 m and an inner diameter of 0.25 mm, and a 5% -diphenylpolymethylsiloxane film having a film thickness of 0.25 μm formed on the inner wall of the tube is used as a fixed layer. The capillary column 4 is accommodated in a thermostat 11 of a gas chromatograph apparatus (trade name: GC / MS, model 5972, manufactured by Hewlett-Packard Co.) comprising a temperature controller 10, a thermostat 11, and a mass spectrometer 5.
[0029]
Next, the temperature controller 10 holds the temperature in the thermostatic chamber 11 at 40 ° C. for 2 minutes, and then heats up to 320 ° C. at a rate of temperature increase of 20 ° C./min, and the mixture of the pyrolysis products is heated. To separate. As a result, the mixture is generally separated from the low boiling point compound to the high boiling point compound, and the separated compounds are introduced into the mass spectrometer 5 in order from the low boiling point compound.
[0030]
In the mass spectrometer 5, a gaseous compound introduced every 0.008 minutes is irradiated with electrons to generate a molecular ion unique to the compound, or the compound is cleaved at a specific position to generate fragment ions. And the molecular ions and fragment ions corresponding to a mass / charge (m / z) ratio in the range of 10 to 150 are continuously scanned to detect the ion intensity of each ion. As a result, one set of ion intensity detection data is obtained per scan every 0.008 minutes.
[0031]
Next, in accordance with the processing procedure stored and held in the main control unit 15, the personal computer 6 once detects the detected data of the ion intensity detected in the capillary column 4 during the holding time of 1 to 16 minutes. The pyrogram creation unit 16 creates a pyrogram. The pyrogram creation unit 16 adds the detection data obtained in each scan to each set corresponding to the scan every 0.008 minutes to obtain a total ion intensity, and arranges the total ion intensity in the order of detection. Thus, the pyrogram shown in FIG. 3 is obtained. 3, the pyrogram of the adhesive of the adhesive tape A is shown in the upper row, and the pyrogram of the adhesive of the adhesive tape B is shown in the lower row (hereinafter, the adhesive tape A is similarly shown in the upper row of FIGS. The data of the pressure-sensitive adhesive and the data of the pressure-sensitive adhesive of the pressure-sensitive adhesive tape B are shown in the lower part).
[0032]
Next, the personal computer 6 follows the processing procedure stored and held in the main control unit 15 and the ionic strength included in the total ionic strength corresponding to each peak of the pyrogram shown in FIG. Are added for each same mass / charge (m / z) ratio, and first sum data of the ion intensity of the molecular ions and fragment ions is calculated. Next, the summation processing unit 17 creates a first summed mass spectrum in which the first summed data is arranged in the mass order of the molecular ions and fragment ions. As a result, the first combined mass spectrum shown in FIG. 4 is obtained.
[0033]
In addition, about the method of producing the said pyrogram and a total mass spectrum, Unexamined-Japanese-Patent No. 2000-35422 has detailed description.
[0034]
In the method of the present embodiment, first, the differences in the first combined mass spectrum shown in FIG. 4 for the adhesive tapes A and B are compared with each other. However, the first combined mass spectrum shown in FIG. 4 is very similar to the adhesive tapes A and B, and it is difficult to distinguish between them.
[0035]
As shown in FIG. 3, both pyrograms of adhesive tapes A and B have the same main component, an isoprene peak at a retention time of about 2 minutes and a limonene peak at a retention time of about 7 minutes. This is probably because the ionic strength of molecular ions and fragment ions contained in the peak occupies a large proportion in the first combined mass spectrum shown in FIG. Note that isoprene is a component that forms the main chain of natural rubber, and limonene is a kind of terpenes that are dimers of isoprene, both of which are abundant in natural rubber, which is the main component of the adhesive. ing.
[0036]
Therefore, in the method of this embodiment, the personal computer 6 is then operated to exclude the isoprene peak and the limonene peak, which are the same main component, and correspond to the residual peak smaller than the main component peak. The detection data of ionic strength is added up for every same mass / charge (m / z) ratio, and second combined data of ionic strength of the molecular ions and fragment ions is calculated. Then, the summation processing unit 17 creates a second summed mass spectrum in which the second summed data is arranged in the mass order of the molecular ions and fragment ions.
[0037]
When the strength of the pyrogram of FIG. 3 is expanded 10 times, it can be seen that the pressure-sensitive adhesive contains a large number of minute components other than isoprene and limonene, as shown in FIG. The minute component is, for example, a thermal decomposition product of an additive such as a tackifier resin, a softener, and an antioxidant for preventing oxidation. Accordingly, the second combined mass spectrum corresponds to the molecular ions and fragment ions constituting the minute component.
[0038]
The obtained 2nd total mass spectrum is shown in FIG. In FIG. 6, regarding the adhesive tapes A and B, different peaks are recognized in the range of 100 to 150 (m / z), and it is clear that the two are different adhesives.
[0039]
In the embodiment, the second combined mass spectrum is compared between the adhesives of the adhesive tapes A and B, and the difference between the two is identified. A database is constructed by collecting the first and second combined mass spectra created by the method described in Japanese Patent No. 35422, and the first and second combined mass spectra of the sample are compared with the database. It may be.
[0040]
Next, using the adhesive of the adhesive tape A as a sample, the result of comparing the first and second combined mass spectra of the adhesive of the adhesive tape A obtained in the above embodiment with the database is shown as each combined mass spectrum. Table 1 and Table 2 show the percentage of coincidence (%). The database is prepared by creating the first and second combined mass spectra for the adhesives of the three types of adhesive tapes A, B, and C by the same method as in the above embodiment. The first combined spectra of the adhesives were designated as data libraries # 1, # 2, and # 3, respectively, and the second combined spectra of the adhesives of the adhesive tapes A, B, and C were designated as data libraries # 4, # 5, and # 6. Is.
[0041]
[Table 1]

[0042]
[Table 2]

[0043]
As is clear from Table 1, the first combined mass spectrum of the pressure-sensitive adhesives of the pressure-sensitive adhesive tape A used as a sample is one of the three types of pressure-sensitive adhesives (data library # 1, # 2, # 3) in the database. Both show similar results and are difficult to identify.
[0044]
However, from Table 2, the second combined mass spectrum of the adhesive of the adhesive tape used as the sample showed a particularly high coincidence rate with the data library # 4 as compared with the data libraries # 5 and # 6. It is clear that the adhesive of the adhesive tape can be identified as the adhesive of the adhesive tape A.
[0045]
Each of the above embodiments has been described by taking the adhesive of the adhesive tape as an example. However, the analysis method of the present invention is different for a plurality of polymer samples having the same main components such as processed food, fragrance, narcotic and drug. It can be used for identification and identification. Moreover, although each said embodiment has demonstrated the polymer sample, the analysis method of this invention can be used also for difference identification and identification of samples other than a polymer sample.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram showing an embodiment of an apparatus used for an analysis method of the present invention.
FIG. 2 is a block diagram showing the configuration of the personal computer shown in FIG.
FIG. 3 is a pyrolysis gas chromatogram (pyrogram) of a polymer sample obtained by the apparatus shown in FIG.
4 is a first combined mass spectrum corresponding to all the peaks shown in FIG.
FIG. 5 is an enlarged view of FIG. 3;
6 is a second combined mass spectrum corresponding to the remaining peaks excluding the peak of the main component in FIG. 5. FIG.
[Explanation of symbols]
2 ... thermal decomposition apparatus, 4 ... capillary column, 5 ... mass spectrometer, 6 ... personal computer.

Claims (2)

For a plurality of samples having the same main component, a step of separating each sample into individual components using a chromatographic apparatus;
Intensities of molecular ions and fragment ions generated by ionizing each component contained in each separated sample at predetermined times are detected and used as detection data for each sample, and each obtained by detection at each predetermined time Chromatogram of each sample by connecting the vertices of the histogram composed of sample detection data as a set and adding the detection data for each set to obtain the total ion intensity and arranging the total ion intensity in the order of detection And the process of creating
The detection data included in the total ion intensity corresponding to each peak of the chromatogram is summed up for each ion of the same mass to obtain first summed data of the intensity of the molecular ion and fragment ion. Creating a first combined mass spectrum of each sample arranged in the order of mass of molecular ions and fragment ions;
Comparing the differences of the first combined mass spectra of each sample with each other;
When the first combined mass spectrum of each sample is recognized to be the same, the detection data included in the total ion intensity corresponding to each peak smaller than the peak of the main component of the chromatogram for each sample is the same mass. Summing up each ion to obtain second summed data of the intensity of the molecular ion and fragment ion, and creating a second summed mass spectrum of each sample in which the summed data is arranged in the order of mass of the molecular ion and fragment ion. Process,
A method for analyzing a sample, comprising the step of comparing the differences in the second total mass spectrum of each sample with each other. Intensities of molecular ions and fragment ions generated by ionizing individual contained components obtained by separating a known sample with a chromatographic apparatus every predetermined time are detected and used as detection data. The detection data of a known sample obtained by detection is set as a set, and the detection data is added for each set to obtain a total ion intensity, and the total ion intensity is arranged in the detection order to connect each vertex of the histogram. The detection data included in the total ion intensity corresponding to each peak in the predetermined range of the chromatogram obtained by adding the ions for each ion of the same mass to obtain the combined data of the intensity of the molecular ions and fragment ions, Creating a combined mass spectrum of the known sample in which the combined data is arranged in the mass order of the molecular ions and fragment ions; Compares the database configured by assembling the combined mass spectra of known samples of several, and said second summer mass spectrum of each sample,
The sample analysis method according to claim 1, wherein each sample is identified by searching a summed mass spectrum of known samples having a high ratio matching the second summed mass spectrum of each sample.

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