JP2020071155A - Data processing device for fourier transform infrared spectrophotometer and fourier transform infrared spectrophotometer - Google Patents

Abstract

To provide a data processing device for FTIR capable of easily specifying a functional group included in a component contained in a specimen.SOLUTION: A data processing device 20 for FTIR includes: a measurement spectrum data acquisition part 22 for acquiring data of measurement spectrum which is an absorbance spectrum or a transmittance spectrum of a specimen to be measured; and a functional group data storage part 211 in which data on a peak of an absorbance spectrum or a transmission spectrum derived from a known functional group is stored in association with information indicating the functional group; and a functional group specification part 24 for specifying the functional group included in a component contained in the specimen to be measured by comparing data of the measurement spectrum with data on the peak stored in the functional group data storage part 211.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a processing device for processing data obtained by a Fourier Transform InfraRed Spectrophotometer (hereinafter referred to as “FTIR”), and a Fourier transform infrared spectrophotometer including the processing device.

  In FTIR, an infrared interference light whose amplitude fluctuates is generated by an interferometer typified by a Michelson interferometer, and the sample is irradiated with the transmitted light that has passed through the sample or the reflected light that is reflected by the sample. Then, a Fourier transform process is performed on this interferogram to obtain a spectrum (power spectrum) in which the horizontal axis represents wave number (or wavelength) and the vertical axis represents intensity. Here, the Michelson interferometer is a device that includes a beam splitter (half mirror), a fixed mirror, a moving mirror, etc., and splits light into two with a beam splitter, one with a fixed mirror and the other with a moving mirror. After being reflected, these two reflected lights are caused to interfere with each other. By moving the movable mirror, the amplitude of the obtained interference light changes. By thus dividing the power spectrum obtained when the sample is irradiated with the infrared interference light by the background power spectrum obtained without the sample, the absorbance spectrum or the transmittance spectrum of the sample can be obtained. Hereinafter, the absorbance spectrum and the transmittance spectrum obtained by the FTIR measurement are collectively referred to as "measurement spectrum".

The measurement spectrum has a peak at a wave number corresponding to the functional group of the component contained in the sample. For example, when the component contains a CH functional group, a peak derived from it appears near the wave number of 2900 cm ⁻¹ , and when it contains a C═O functional group, a peak appears near the wave number of 1770 cm ⁻¹ . Therefore, the functional group can be identified from the peak appearing in the measurement spectrum.

Specifying the functional groups contained in the components contained in the sample in this manner can be used to confirm chemical changes such as synthesis and deterioration of the sample. For example, Patent Document 1 describes that when a polycarbonate (PC) resin is deteriorated by heat, a peak derived from a carbonyl group (C = O functional group) appears near a wave number of 1770 cm ^{-1 in} a measurement spectrum. Further, in the ABS resin, when it is deteriorated by heat, a C═O functional group is generated, and a peak appears near the wave number of 1770 cm ^{−1 in the} measurement spectrum. Therefore, the presence or absence of deterioration of the resin and the progress of deterioration can be grasped from the presence or absence of these peaks and the strength of the peaks when they appear.

JP 2018-031739

  The FTIR has a library that collects the spectrum data of known substances, and by comparing the measured spectrum obtained from an unknown sample with the data of the library, a device that has the function of identifying the components contained in the unknown sample is available. is there. However, in such a device, the functional group contained in the component cannot be specified, and the operator has to specify the functional group by examining literatures and the like.

  The problem to be solved by the present invention is to provide a data processing device for FTIR capable of easily specifying a functional group contained in a component contained in a sample, and an FTIR having the device.

A data processing device for Fourier transform infrared spectrophotometer (FTIR) according to the present invention made to solve the above problems,
A measurement spectrum data acquisition unit that acquires the data of the measurement spectrum that is the absorbance spectrum or the transmittance spectrum of the sample to be measured,
Data of a peak of an absorbance spectrum or a transmittance spectrum derived from a known functional group, a functional group data storage unit that is stored in association with information indicating the functional group,
A functional group specifying unit for specifying a functional group contained in the component contained in the sample to be measured by comparing the data of the measurement spectrum with the data of the peak stored in the functional group data storage unit. It is characterized by

  In the data processing apparatus for FTIR according to the present invention, the data of the measurement spectrum obtained from the sample to be measured, and the peak data stored in the functional group data storage unit obtained from the known functional group, the functional group identification unit. By comparing with, it is possible to specify the functional group contained in the component contained in the sample to be measured. This eliminates the need for the operator to search a document or the like to specify the functional group, and the functional group can be easily specified.

  For example, the wave number at the peak top of the peak in the measurement spectrum obtained from the sample to be measured (wavelength or frequency may be used instead of wave number; the same applies below) and a certain functional group stored in the functional group data storage unit. When the wave number of the peak top in the peak data derived from is within a predetermined error range, it indicates the functional group stored in the functional group data storage unit in association with the peak derived from the functional group. Based on the information, the component contained in the sample to be measured is identified as having the functional group. Alternatively, in a predetermined wave number range determined for each functional group, the degree of coincidence between the peak obtained from the sample to be measured and the peak stored in the functional group data storage unit is determined, and the degree of coincidence is a predetermined value or more. In some cases, it may be specified that the component has the functional group.

  The information indicating the functional group stored in the functional group data storage unit includes the name of the functional group, the structural formula, and the like.

  The measurement spectrum data acquisition unit may be one that acquires by obtaining an absorbance spectrum or a transmittance spectrum from an interferogram obtained by FTIR, or by another device (for example, a data processing device that an existing FTIR has). It may be one that acquires the obtained absorbance spectrum or transmittance spectrum. Alternatively, it may be compatible with both of these two acquisition methods.

The data processing device for FTIR according to the present invention further comprises
An input section through which an operator performs input operation,
From the measurement spectrum acquired by the measurement spectrum data acquisition unit, a measurement spectrum data extraction unit that extracts data of the measurement spectrum within a wave number range set by an input operation by the input unit,
Data of the measurement spectrum extracted by the measurement spectrum data extraction unit, and information indicating a functional group set by an input operation by the input unit, the functional group data to be stored in the functional group data storage unit in association with each other A storage operation unit is preferably provided.

  According to the configuration including such an input unit, the measurement spectrum data extraction unit, and the functional group data storage operation unit, the operator shows the peak data derived from the functional group and the functional group from the obtained measurement spectrum. Information and information can be newly stored in the functional group data storage unit, and can be used when processing the measurement data obtained thereafter.

Fourier transform infrared spectrophotometer (FTIR) according to the present invention,
An interferometer that generates infrared interference light with varying amplitude, an infrared interference light irradiation unit that irradiates the sample with the infrared interference light, and detects transmitted light that passes through the sample or reflected light that is reflected by the sample An infrared spectrophotometer body having a detector to
The power spectrum is obtained by subjecting the interferogram, which is the intensity data detected by the detector, to a Fourier transform process, and the power spectrum is divided by the power spectrum of the background to obtain an absorbance spectrum or transmittance of the sample. A measurement spectrum data acquisition unit that acquires data of a measurement spectrum that is a spectrum,
Data of a peak of an absorbance spectrum or a transmittance spectrum derived from a known functional group, a functional group data storage unit that is stored in association with information indicating the functional group,
A functional group specifying unit for specifying a functional group contained in the component contained in the sample to be measured by comparing the data of the measurement spectrum with the data of the peak stored in the functional group data storage unit. It is characterized by

  It is preferable that the FTIR according to the present invention further includes the input unit, the measured spectrum data extraction unit, and the functional group data storage operation unit, similarly to the Fourier transform infrared spectrophotometer data processing device.

  According to the data processing device for FTIR and the FTIR of the present invention, the functional group contained in the sample can be easily specified.

1 is a schematic configuration diagram showing an embodiment of a FTIR data processing device and FTIR according to the present invention. Absorbance spectrum data derived from (a) C = O functional group and (b) C-H functional group. The figure which shows the light absorption spectrum data and the data processing result before (a) ABS resin heating and (b) heating. FIG. 8 is a schematic configuration diagram showing a modification of the FTIR data processing device and FTIR of the present embodiment. From the measurement spectrum obtained by FTIR, an example of a screen displayed on the display unit when performing an operation of newly storing the data of the peak derived from the functional group and the information indicating the functional group in the functional group data storage unit. FIG.

  Embodiments of an FTIR data processing device and FTIR according to the present invention will be described with reference to FIGS. 1 to 5.

  FIG. 1 shows a schematic configuration of the FTIR 1 of this embodiment. The FTIR 1 has an FTIR main body 10, a data processing device 20, an input unit 30, and a display unit 40. The data processing device 20 corresponds to the embodiment of the FTIR data processing device of the present invention. The input unit 30 is a normal input device such as a keyboard, a mouse and a touch panel, and the display unit 40 is a normal display device such as a display and a touch panel. Hereinafter, the configurations of the FTIR main body 10 and the data processing device 20 will be described in detail.

  The FTIR main body 10 includes an infrared light source 11, a beam splitter 12, a fixed mirror 13, a moving mirror 14, a sample chamber 15, a first detector 161, a second detector 162, a semiconductor laser 17, a laser first mirror 181, and a laser. It has a second mirror for use 182 and a control unit 19. Among these components, the infrared light source 11, the beam splitter 12, the fixed mirror 13, and the movable mirror 14 constitute a main interferometer which is an interferometer for infrared light used for measurement. On the other hand, the semiconductor laser 17, the first laser mirror 181, the beam splitter 12, the fixed mirror 13, and the movable mirror 14 constitute a control interferometer for controlling the movement of the movable mirror 14.

  The infrared light source 11 is a light source that generates infrared light in which many wavelengths are superimposed. The beam splitter 12 is arranged at a position where infrared light emitted from the infrared light source 11 is incident, and transmits half of the incident infrared light in terms of intensity ratio and reflects the other half in the 90 ° direction. Is. The fixed mirror 13 is arranged at a position where the infrared light reflected by the beam splitter 12 is incident, and the movable mirror 14 is arranged at a position where the infrared light transmitted through the beam splitter 12 is incident. The positions of the fixed mirror 13 and the movable mirror 14 may be opposite to each other. Both the fixed mirror 13 and the movable mirror 14 are arranged so as to reflect the incident infrared light in the direction of 180 ° and thereby cause the infrared light to enter the beam splitter 12. The fixed mirror 13 has a fixed position, while the movable mirror 14 moves in a direction parallel to the optical path so as to change the distance from the beam splitter 12.

  The infrared light reflected by the fixed mirror 13 and the infrared light reflected by the movable mirror 14 enter the beam splitter 12 and are overlapped with each other to form interference light in which the two infrared lights interfere with each other. The sample chamber 15 is arranged at a position on which the interference light output from the beam splitter 12 is incident. A sample is stored in the sample chamber 15. The first detector 161 is arranged at a position where the interference light passing through the sample chamber 15 (and the sample in the sample chamber 15) is incident, and detects the intensity of the interference light.

  The semiconductor laser 17 is composed of monochromatic (one wavelength) light, and emits a monochromatic laser beam having a diameter sufficiently smaller than that of the infrared light generated by the infrared light source 11. In FIG. 1, the optical path of the infrared light generated by the infrared light source 11 is represented by a shaded band, and the optical path of the laser beam is represented by a thick broken line. The first laser mirror 181 is arranged in the optical path of the infrared light between the infrared light source 11 and the beam splitter 12, and makes the laser beam emitted from the semiconductor laser 17 parallel to the infrared light. The light is reflected in the direction of incidence on the beam splitter 12. As a result, the laser beam is split into two by the beam splitter 12, one of which is reflected by the fixed mirror 13 and the other of which is reflected by the movable mirror 14 and enters the beam splitter 12 again. Here, when the optical path difference between the laser beam reflected by the fixed mirror 13 and the laser beam reflected by the movable mirror 14 becomes an integral multiple of the wavelength of the laser beam, the intensities of the laser beams are interfered with each other. Be strengthened. The second laser mirror 182 is arranged between the beam splitter 12 and the sample chamber 15, and reflects the laser beam (monochromatic interference light) that has interfered as described above and makes it enter the second detector 162. The second detector 162 detects the intensity of the interfered laser beam. The sizes of the laser first mirror 181 and the laser second mirror 182 are sufficiently smaller than the diameter of the infrared light, and the infrared light is reflected by the laser first mirror 181 and the laser second mirror 182. There is little interruption.

  The control unit 19 controls ON / OFF of the outputs of the infrared light source 11 and the semiconductor laser 17, and the movement of the movable mirror 14.

  The data processing device 20 creates data of the measured absorbance spectrum or transmittance spectrum of the sample (hereinafter collectively referred to as “measurement spectrum”) based on the infrared interference light measured by the FTIR main body 10. In addition, it is an apparatus for performing a process of specifying a functional group contained in a sample based on the measured spectra thereof. The data processing device 20 functionally includes a storage unit 21, a measurement spectrum data creation unit 22, a measurement spectrum data acquisition unit 23, and a functional group identification unit 24. Of these units, the storage unit 21 is embodied by a storage medium such as a hard disk or a memory, and the other units are embodied by a central processing unit (CPU) and software.

  The storage unit 21 functionally has a functional group data storage unit 211 and a measurement spectrum data storage unit 212. The functional group data storage unit 211 stores, for various known functional groups, the wave number (or wavelength or frequency) of the peak top of the measurement spectrum derived from the functional groups. Value) and the data of the measured spectrum (peak profile data) within a predetermined wave number range before and after the wave number of the peak top are stored together with the name of the functional group corresponding to the wave number of the peak top. ing. These data may be input in advance to the functional group data storage unit 211 by the manufacturer of the FTIR 1 or the data processing device 20 alone, or may be input by the operator using the input unit 30. The measurement spectrum data storage unit 212 stores the data of the measurement spectrum created by the measurement spectrum data creation unit 22 described below. Note that, at a minimum, it is possible to specify the functional group if there is peak top wave number data. Therefore, the peak profile data is not recorded in the storage unit 21, but only the peak top wave number and the functional group name. May be recorded in the storage unit 21.

  While the movable mirror 14 is moving, the measurement spectrum data creating unit 22 moves based on the intensity and the oscillation wavelength of the interference light of the laser beam detected by the second detector 162, and moves the optical path through the fixed mirror 13. After the optical path difference of the optical path passing through the mirror 14 is obtained, the intensity of the infrared interference light detected by the first detector 161 is calculated by the fast Fourier transform with respect to the interferogram showing the distribution by the optical path difference obtained as described above. Data of the measured spectrum is created by performing the conversion.

  The measurement spectrum data acquisition unit 23 acquires the measurement spectrum data of the sample for which the functional group is specified from the measurement spectrum data of each sample stored in the measurement spectrum data storage unit 212. Note that the measurement spectrum data acquisition unit 23 may acquire the data at the same time that the measurement spectrum data creation unit 22 creates the measurement spectrum data.

  The functional group identification unit 24 performs measurement by comparing the measurement spectrum data acquired by the measurement spectrum data acquisition unit 23 with the peak data (functional group peak data) stored in the functional group data storage unit 211. This is intended to specify the functional group contained in the component contained in the target sample. The comparison of these two data is, for example, for each of the plurality of functional group peak data stored in the functional group data storage unit 211 within a predetermined wave number range from the peak top wave number of the functional group peak data. The degree of coincidence between the peak profile of the functional group peak data and the peak profile of the measurement spectrum is obtained, and when the value of the degree of coincidence is a predetermined value or more, the component in the measurement target sample is a functional group corresponding to the functional group peak data. To have. Alternatively, without using the peak profile, when the peak top wave number of the measurement spectrum exists within a predetermined wave number range from the peak top wave number of the functional group peak data, the component in the measurement target sample is the functional group peak data. May have a functional group corresponding to.

  After the functional group identification unit 24 identifies the functional groups contained in the components in the measurement target sample, the display unit 40 displays the measurement spectrum acquired by the measurement spectrum data acquisition unit 23, and the functional group identification unit 24 displays the functional groups. The peak profile of the functional group peak data used for the specification and the name or structural formula of the specified functional group are displayed.

Next, an example in which the components contained in the sample are specified by using the data processing device 20 of the present embodiment will be described with reference to FIGS. 2 and 3. The measurement spectra measured before heating the ABS resin and after heating it at 250 ° C. for 2 hours were the targets for data processing. As described above, in the ABS resin, when it is deteriorated by heat, a C = O functional group is generated, and a peak appears near the wave number 1770 cm ^{-1 of the} measured spectrum. The functional group peak data (FIG. 2A), which is the peak profile of the peak due to the C = O functional group, and the structural formula (C = O) of the functional group are stored in the functional group data storage unit 211 in advance. In this experiment, the functional group data storage unit 211 was also made to store the functional group peak data of the CH functional group (FIG. 2B) and the structural formula (CH) of the functional group. In the peak profile of CH functional group, two peaks appear close to each other near the wave number of 2900 cm ^-1 . If the data processing device 20 operates correctly, the CH functional group peak is not detected in the measurement spectrum of the ABS resin before and after heating. The functional group peak data for the C = O functional group was extracted from the polyethylene terephthalate (PET) absorption spectrum data, and the CH functional group functional group peak data was derived from the polyethylene (PE) absorption spectrum data. It was extracted. In addition, for the sake of simplicity in this experiment, data other than the C═O functional group and the CH functional group is not stored in the functional group data storage unit 211.

The results of data processing are shown in FIG. 3 (a) before heating the ABS resin and in FIG. 3 (b) after heating to 250 ° C., respectively. 3A and 3B, the measurement spectrum (absorbance spectrum) is displayed on the upper stage, and the horizontal axis represents the same wave number range as the measurement spectrum, and the C = O functional group stored in the functional group data storage unit 211. The peak profile of the peak due to the group is displayed in the middle row. Regarding the C = O functional group and the CH functional group, the lower row shows a score indicating the degree of agreement between the measured spectrum data and the functional group peak data, the file name of the functional group peak data file, the structural formula of the functional group, and the file. Comments are shown in the table. Before heating the ABS resin, no peak was observed in the vicinity of 1770 cm ^{-1 in the} measured spectrum, and the lower table shows that both the C = O functional group and the CH functional group have a similarly low score. .. On the other hand, after heating the ABS resin to 250 ° C., a peak having a wider width than the peaks seen in other wave numbers is observed near 1770 cm ^{−1 in the} measurement spectrum. Then, the score of the C = O functional group shown in the lower table is higher than the score of the C = O functional group in (a) and the score of the CH functional group in (a) and (b), The peak around 1770 cm ⁻¹ in this measurement spectrum is shown to be derived from the C═O functional group.

  In addition, here, although the data processing is performed for the entire wave number range in which the data of the measured spectrum is obtained, the operator uses the input unit 30 to specify a part of the wave number range, Data processing may be performed only within this designated range.

  Next, a modified example of the FTIR and the FTIR data processing device of the above embodiment will be described with reference to FIG. The FTIR 1A of this modified example has an FTIR main body 10 which is the same as the FTIR 1 described above, and a data processing device 20A which differs from the data processing device 20 in the following points. The data processing device 20A functionally has a measurement spectrum data extraction unit 25 and a functional group data storage operation unit 26 together with the respective components of the data processing device 20. These are also embodied by a CPU and software, like the measurement spectrum data creation unit 22, the measurement spectrum data acquisition unit 23, and the functional group identification unit 24.

  The measurement spectrum data extraction unit 25 causes the display unit 40 to display the measurement spectrum acquired by the measurement spectrum data acquisition unit 23, and then causes the operator to use the input unit 30 to extract the measurement spectrum data. The operation for setting the range is executed. For example, as shown in FIG. 5, the wave number range 41 displays two marks 411 and 412 composed of vertically extending lines or triangular marks on the measured spectrum displayed on the display unit 40. It can be set by designating the upper limit value and the lower limit value of the wave number range by the operator laterally moving 412 using the input unit 30 such as a mouse. Alternatively, the operator may be allowed to input the upper limit value and the lower limit value of the wave number range.

  The functional group data storage operation unit 26 executes an operation of causing the operator to input the name or structural formula of the functional group as information indicating the functional group that is the origin of the peak existing in the set wave number range, The operation of storing the measurement spectrum data extracted by the measurement spectrum data extraction unit 25 in the functional group data storage unit 211 together with the information is executed. The information indicating the functional group is input to the “functional group” column in the table 42 displayed on the display unit 40, as shown in FIG. 5, for example. In the example shown in FIG. 5, the operator can input “file name” and “comment” in addition to “functional group”.

  By the operations of the measurement spectrum data extraction unit 25 and the functional group data storage operation unit 26, from the measurement spectrum obtained by the FTIR main body 10 (created by the measurement spectrum data creation unit 22 based on the interferogram) to the functional group. The derived peak data and the information indicating the functional group can be newly stored in the functional group data storage unit 211, and can be used for data processing of measurement data obtained thereafter.

  The present invention is not limited to the above-described embodiments and modified examples, and various modifications can be made within the scope of the gist of the present invention. For example, although the FTIR main body 10 and the data processing device 20 or 20A are combined in the above-described embodiment and modification, the data processing device 20 or 20A may be used alone. In this case, the data processing device 20 or 20A is provided with a data input device, and the data of the interferogram acquired by the FTIR provided outside the data processing device 20 or 20A is transferred from the data input device to the measured spectrum data creation unit 22. To the measurement spectrum data creation unit 22 or the measurement spectrum data creation unit 22 creates measurement spectrum data created outside the data processing device 20 or 20A. You may make it input into 22.

1, 1A ... FTIR
Reference numeral 10 ... FTIR main body 11 ... Infrared light source 12 ... Beam splitter 13 ... Fixed mirror 14 ... Moving mirror 15 ... Sample chamber 161 ... First detector 162 ... Second detector 17 ... Semiconductor laser 181 ... Laser first mirror 182 ... Second laser mirror 19 ... Control units 20, 20A ... Data processing device 21 ... Storage unit 211 ... Functional group data storage unit 212 ... Measurement spectrum data storage unit 22 ... Measurement spectrum data creation unit 23 ... Measurement spectrum data acquisition unit 24 ... Functional group identification section 25 ... Measured spectrum data extraction section 26 ... Functional group data storage operation section 30 ... Input section 40 ... Display section 41 ... Wave number range 411, 412 ... Mark 42 ... Table

Claims (4)

A measurement spectrum data acquisition unit that acquires the data of the measurement spectrum that is the absorbance spectrum or the transmittance spectrum of the sample to be measured,
Data of a peak of an absorbance spectrum or a transmittance spectrum derived from a known functional group, a functional group data storage unit that is stored in association with information indicating the functional group,
A functional group specifying unit for specifying a functional group contained in the component contained in the sample to be measured by comparing the data of the measurement spectrum with the data of the peak stored in the functional group data storage unit. A data processing device for a Fourier transform infrared spectrophotometer, characterized in that further,
An input section through which an operator performs input operation,
From the measurement spectrum acquired by the measurement spectrum data acquisition unit, a measurement spectrum data extraction unit that extracts data of the measurement spectrum within a wave number range set by an input operation by the input unit,
Data of the measurement spectrum extracted by the measurement spectrum data extraction unit, and information indicating a functional group set by an input operation by the input unit, the functional group data to be stored in the functional group data storage unit in association with each other The data processing apparatus for a Fourier transform infrared spectrophotometer according to claim 1, further comprising a storage operation unit. An interferometer that generates infrared interference light with varying amplitude, an infrared interference light irradiation unit that irradiates the sample with the infrared interference light, and detects transmitted light that passes through the sample or reflected light that is reflected by the sample An infrared spectrophotometer body having a detector to
The power spectrum is obtained by subjecting the interferogram, which is the intensity data detected by the detector, to a Fourier transform process, and the power spectrum is divided by the power spectrum of the background to obtain an absorbance spectrum or transmittance of the sample. A measurement spectrum data acquisition unit that acquires data of a measurement spectrum that is a spectrum,
Data of a peak of an absorbance spectrum or a transmittance spectrum derived from a known functional group, a functional group data storage unit that is stored in association with information indicating the functional group,
A functional group specifying unit for specifying a functional group contained in the component contained in the sample to be measured by comparing the data of the measurement spectrum with the data of the peak stored in the functional group data storage unit. A Fourier transform infrared spectrophotometer characterized by the following. further,
An input section through which an operator performs input operation,
From the measurement spectrum acquired by the measurement spectrum data acquisition unit, a measurement spectrum data extraction unit that extracts data of the measurement spectrum within a wave number range set by an input operation by the input unit,
Data of the measurement spectrum extracted by the measurement spectrum data extraction unit, and information indicating a functional group set by an input operation by the input unit, the functional group data to be stored in the functional group data storage unit in association with each other The Fourier transform infrared spectrophotometer according to claim 3, further comprising a storage operation unit.

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