Raman spectroscopic analysis method and microscopic raman spectrometer

Abstract

Provided is a Raman spectroscopic analysis method and a microscopic Raman spectrometer that can identify data of Raman scattered light obtained before an analysis target sample is damaged by laser light and analyze the structure of the analysis target sample based only on the data. The Raman spectroscopic analysis method determines the number of irradiations of laser light that damages the analysis target sample in a plurality of Raman spectroscopic measurements and performs structural analysis of the analysis target sample using data of Raman scattered light obtained when the analysis target sample is in an undamaged state. A Raman spectroscopic analysis method that spectrally separates obtained Raman scattered light and determines the upper limit of the number of irradiations in which the analysis target sample is not damaged based on the total scattering intensity in a specific wave number range, the ratio of the total scattering intensity in the specific wave number range of each irradiation to the total scattering intensity in the specific wave number range of the first irradiation, and the correlation coefficient thereof, and uses data of Raman scattered light up to the upper limit of the number of irradiations.

Description

Technical Field

[0001] This invention relates to a Raman spectrophotometric analysis method and a micro Raman spectrophotometric device. Background Technology

[0002] The Raman spectrometer is used for the following determination method: structural analysis of a sample is achieved by performing spectroscopic analysis on Raman scattered light of different wavelengths generated from the sample when it is irradiated with an excitation laser (e.g., Patent Document 1). Among these methods, microscopic Raman spectrometry has been developed as a means of analyzing the chemical structure of minute parts and has been widely used in recent years.

[0003] Because Raman scattered light has a much lower intensity than laser light, high-intensity laser light is required. Furthermore, the low intensity of Raman scattered light results in a low signal-to-noise (S / N) ratio in the obtained spectrum. Therefore, it is necessary to subject the analyte to laser light multiple times, measure the Raman scattered light multiple times, and accumulate the results to obtain a high S / N ratio.

[0004] However, if the laser light intensity is too strong or the number of laser beams is too high, the damage to the analyte sample caused by the laser light will increase. Especially when the analyte sample is an organic material, the sample may be burned due to carbonization or thermal decomposition caused by laser light irradiation. In micro Raman spectrometry, where the analyte is a very small area, the area irradiated by the laser light is concentrated in a very small part, so the burn damage to the analyte sample becomes significant.

[0005] If the sample is burned, the structure of the sample to be analyzed will change, so it is impossible to obtain Raman scattering data based on the original structure. Therefore, in order to perform accurate structural analysis, it is necessary to measure the Raman scattering again.

[0006] However, because the structure of the burned part is destroyed, even if the same location is measured, it is impossible to obtain Raman scattered light that reflects the original structure.

[0007] [Existing Technical Documents]

[0008] [Patent Literature]

[0009] Patent Document 1: Japanese Patent Application Publication No. 2006-113021 Summary of the Invention

[0010] [The problem the invention aims to solve]

[0011] Therefore, it is necessary to identify the Raman scattering data obtained before the analyte sample is damaged by laser light during Raman spectrometry, and to perform structural analysis of the analyte sample solely based on this pre-damage Raman scattering data.

[0012] The purpose of this invention is to provide a Raman spectrophotometric analysis method, which determines the number of times the sample is irradiated by laser light that causes damage during multiple Raman spectrophotometric measurements, and uses the Raman scattered light data obtained when the sample is in an undamaged state to perform structural analysis of the sample.

[0013] Therefore, the present invention aims to provide a micro Raman spectrometer for performing the Raman spectroscopic analysis method.

[0014] [Technical means to solve the problem]

[0015] That is, the present invention provides

[0016] A Raman spectrophotometric analysis method,

[0017] It uses the objective lens optical elements to illuminate the sample being analyzed with laser light emitted from the laser source.

[0018] Raman scattered light was obtained from the sample being analyzed.

[0019] The total scattering intensity within a specific wavenumber range is determined by spectroscopying the obtained Raman scattered light.

[0020] The process of repeatedly calculating the total scattering intensity within a specific wavenumber range based on the irradiation by the laser light is performed multiple times.

[0021] Calculate the ratio of the total scattered intensity in each specific wavenumber range of the irradiation to the total scattered intensity in the specific wavenumber range of the first irradiation.

[0022] Calculate the correlation coefficient between the total scattered intensity within the specific wavenumber range of the first irradiation and the total scattered intensity within the specific wavenumber range for each subsequent irradiation.

[0023] Based on at least one of the following relationships: the number of measurements and the total scattered intensity at each of the irradiation numbers, or the ratio of the total scattered intensity in the specific wavenumber range for each irradiation number to the total scattered intensity in the specific wavenumber range relative to the first irradiation; and

[0024] The relationship between the number of measurements and the correlation coefficient.

[0025] To determine the upper limit of the number of irradiations required to ensure the sample remains undamaged during analysis.

[0026] And use the data of Raman scattered light prior to the number of irradiations at the upper limit.

[0027] In addition, the present invention provides

[0028] A micro Raman spectrometer,

[0029] It has the following characteristics:

[0030] Laser source;

[0031] Microscope Optics;

[0032] A plate is used to fix the sample being analyzed.

[0033] A beam splitter and Raman scattering detection system, which has the following features:

[0034] The storage section stores the number of laser irradiations and the Raman scattering spectrum at that time.

[0035] A computation unit that calculates the total scattering intensity of Raman scattered light within a specific wavenumber range under each laser irradiation;

[0036] A calculation unit that calculates the ratio of the total scattered intensity in each specific wavenumber range of irradiation, relative to the total scattered intensity in the specific wavenumber range of the first irradiation;

[0037] The computational unit calculates the correlation coefficient between the total scattered intensity in the specific wavenumber range of the first irradiation and the total scattered intensity in the specific wavenumber range for each irradiation number; and

[0038] The display unit shows the relationship between at least one of the number of measurements and the total scattering intensity at each of the irradiation numbers, or the ratio of the total scattering intensity in the specific wavenumber range for each irradiation number to the total scattering intensity in the specific wavenumber range for each irradiation number, relative to the total scattering intensity in the specific wavenumber range for the first irradiation, and...

[0039] The relationship between the number of measurements and the correlation coefficient;

[0040] The analysis unit determines the relationship between at least one of the following: the number of measurements and the total scattering intensity at each of the irradiation numbers; or the ratio of the total scattering intensity in the specific wavenumber range for each irradiation number to the total scattering intensity in the specific wavenumber range relative to the first irradiation; and

[0041] The upper limit of the number of irradiations required to ensure that the sample remains undamaged is determined based on the relationship between the number of measurements and the correlation coefficient.

[0042] [The effects of the invention]

[0043] According to the present invention, a Raman spectrophotometric analysis method is provided, which can identify the Raman scattered light data obtained before the analyte sample is damaged by laser light during Raman spectrophotometry, and perform structural analysis of the analyte sample based solely on this pre-damage Raman scattered light data.

[0044] Furthermore, according to the present invention, a micro Raman spectrophotometer for performing the Raman spectrophotometric analysis method is provided. Attached Figure Description

[0045] Figure 1 This is a flowchart illustrating the Raman spectrophotometric analysis method of the present invention.

[0046] Figure 2 This is a schematic diagram of a Raman spectrum.

[0047] Figure 3 This is a schematic diagram showing the changes in the Raman spectrum of the sample before and after it was damaged by laser light.

[0048] Figure 4 It is relative to n and plots Sn or s n A diagram showing the time.

[0049] Figure 5 This is a diagram showing r relative to n.

[0050] Figure 6 This is a schematic diagram illustrating one aspect of the micro Raman spectrometer of the present invention. Detailed Implementation

[0051] Figure 1 This is a flowchart illustrating the Raman spectrophotometric analysis method of the present invention using a micro Raman spectrophotometer.

[0052] In steps 1 and 2, laser light is irradiated onto the desired analyte region of the sample using the objective lens optical element, thereby obtaining Raman scattered light from the sample. The obtained Raman scattered light is then dispersed, and the wavelength or wavenumber is determined accordingly. Figure 2 The diagram illustrates how Raman spectra are obtained.

[0053] Typically, because the intensity of Raman spectra is very weak, by repeatedly performing steps 1 to 3, a result such as... can be obtained. Figure 2 The spectrum is schematically shown in the diagram.

[0054] However, if steps 1 to 3 are repeated multiple times, the analyte sample is easily damaged by the laser light, such as decomposition, oxidation, and charring. This is especially true when the analyte sample is organic, where burning can occur, and the damage caused by the laser light becomes more severe.

[0055] Furthermore, in the case of analysis by micro Raman spectroscopy, the laser light is locally concentrated through the objective lens optical elements, thus the burn-off of the analyte sample becomes significant.

[0056] Figure 3 The diagram schematically illustrates the changes in the Raman scattering spectrum of the sample before and after it was burned by laser light.

[0057] like Figure 3 As shown, when the analyte sample is damaged by laser light, such as ablation, the baseline of the Raman scattering spectrum rises. Furthermore, when the analyte sample is organic, a 1350 cm⁻¹ peak appears due to carbonization. -1 Nearby D-band and 1590cm -1 The nearby G-band. As a result, the previously obtainable Raman scattering spectrum becomes smaller and broader, which can sometimes hinder structural analysis.

[0058] Because the changes in the Raman scattering spectrum caused by damage occur gradually, it is difficult to determine from the specific laser irradiation episode that the damage occurred based solely on the spectral changes. Furthermore, since damage to the analyte sample is sometimes determined after Raman analysis, the analysis may be futile, or the sample may need to be readjusted.

[0059] Once the number of laser irradiations that caused the damage can be determined, accurate analysis can be performed by using the Raman scattering spectra prior to the number of irradiations that caused the damage. Furthermore, the analysis will not be in vain, and there will be no need to readjust the sample being analyzed.

[0060] Therefore, in step 3, the analytical method of the present invention calculates the total scattering intensity within a specific wavenumber range in the Raman scattering spectrum obtained in step 2. Regarding the wavenumber range, it is not necessary to calculate the total scattering intensity for all wavenumbers; only the wavenumbers of the spectrum expected to be possessed by the analyte sample are required.

[0061] Calculate the total scattering intensity Sn within the specified wavenumber range. The total scattering intensity is equivalent to the area enclosed by the spectrum and the horizontal axis of the spectrum within the specified wavenumber range. For example, when Raman scattering intensity is represented by an electrical signal, it is represented by the integral of all electrical signals within the specified wavenumber range. Furthermore, Sn represents the total scattering intensity at the nth laser irradiation.

[0062] In step 4, steps 1 to 3 are repeated to determine Sn under each laser irradiation. The number of irradiations n and the total scattering intensity Sn can then be stored and retrieved when appropriate, or n and Sn can be displayed on a display device for each number of irradiations.

[0063] Additionally, in step 5, the intensity ratio s of Sn relative to the total scattering intensity S1 during the first laser irradiation is calculated. n . s n It is represented by the following formula (1).

[0064] s n =Sn / S1 (1)

[0065] In step 5, Sn can be calculated each time it is calculated in step 4, or it can be calculated from s2 to S after the Raman spectrometry measurement is completed. n The calculation.

[0066] In step 6, S1 and each S are calculated. n The correlation coefficient r is the coefficient used in statistical processing and is the value obtained by dividing the covariance by the standard deviation.

[0067] The covariance is the value obtained by dividing the deviation of Sn by the number of measurements n, and the standard deviation is the square root of the sum of the squares of the average of the total scattering intensity obtained under n laser irradiation and the differences between each Sn.

[0068] Similar to n and Sn, s can be... n And r are stored and retrieved when appropriate, or s is displayed on the display device simultaneously with n and Sn for each irradiation cycle. n 、r.

[0069] In step 7, according to the Sn or s n The upper limit of n for the sample being undamaged is determined by the relationship between n and r.

[0070] like Figure 3 As shown, if the analyte sample is damaged, the baseline of the Raman scattering spectrum rises. That is, Sn is constant before damage, but increases as the baseline rises after damage. n Similarly, it increases after the analyte sample is damaged. Therefore, it is only necessary to determine Sn or s. n If n increases, then the next n-1 becomes the upper limit of the number of times the sample being analyzed remains undamaged.

[0071] Furthermore, such as Figure 3 As shown, when the analyte sample is an organic compound, a 1350 cm³ layer appears due to carbonization. -1 Nearby D-peak and 1590cm -1 The nearby G-peak. As a result, Sn or s rises as described above. n It will increase, while r will decrease due to the influence of new peak values ​​caused by burning, etc.

[0072] Therefore, by determining n as r decreases, the amount of organic damage caused by burn-off can be determined. The next n-1 before n represents the upper limit of the number of times the analyte sample has not been burned off.

[0073] Regarding the n and Sn or s n The relationship between n and r, and the relationship between n and r, are determined by retrieving the values ​​of n, Sn, or s that have been stored so far. n By comparing Sn and s with n, the upper limit of the number of times the analyzed sample remained undamaged can be determined. If Sn or s is plotted relative to n... n Compared to plotting r with n, it is easier to understand visually.

[0074] Figure 4 and Figure 5 This schematically illustrates Sn or s plotted relative to the n. n The result is plotted relative to n when r is plotted.

[0075] like Figure 4 As shown, Sn or s is plotted relative to n. n In the case of Sn or s relative to a certain n n As the value of increases, when the points are connected by a straight line, the line that was originally parallel to the x-axis changes into a continuously rising n. Here, n is the number of times the analyzed sample was irradiated with damaging laser light.

[0076] In addition, such as Figure 5 As shown, when r is plotted relative to n, the value of r decreases relative to a certain n. When the points are connected by a straight line, the straight line that was originally parallel to the x-axis changes into a continuously decreasing n. Here, n is the number of times the analytical sample exhibits a new peak value due to burn-off, etc., and is also the number of times the analytical sample has been irradiated by the burn-off laser light.

[0077] That is, when the sample being analyzed is damaged, Sn or s exists. n The value of n increases. Therefore, Sn is compared with its previous Sn-1 or s. n Compared to the previous s n-1 By comparison, we can determine whether Sn-1 < Sn or s n-1 <s n From n, we can determine the number of times the sample was irradiated by the laser light that caused the burn, and thus determine the upper limit of the number of times the sample was not burned.

[0078] Alternatively, a certain threshold d can be predetermined, which will result in Sn-Sn-1≥d or s n -s n-1The upper limit of the number of times the sample was not burned is determined by the number of times n, such as ≥d, was irradiated by the laser light that caused the burn.

[0079] The same applies to r and n.

[0080] also, Figure 4 and Figure 5 This schematically illustrates Sn or s plotted relative to n. n Compared to the result when r is plotted with n, there are also cases where the change is very small. Therefore, by adjusting Sn or s n Linear regression analysis performed relative to the plotting of n and r relative to n, and determining the upper limit of the number of times the sample under analysis is not damaged based on the change in the slope of the straight line, can more accurately determine the number of times, and is therefore preferred.

[0081] Once the number of times n of laser light that caused damage to the sample is determined using the method described above, the number of times the sample was irradiated without damage before the (n-1)th time can be identified. Therefore, by using the data before the (n-1)th time to perform structural analysis on the sample, accurate analysis can be achieved.

[0082] As described above, if each n and its Raman scattering spectrum are stored, then the analysis can be performed by simply retrieving the Raman scattering spectrum up to the upper limit of the number of times the sample has been irradiated with laser light without damage, as determined above.

[0083] Figure 6 The diagram shows a schematic representation of the morphology of the micro Raman spectrometer used for the analytical method described above.

[0084] Figure 6 The micro Raman spectrometer shown includes: a laser light source A, a microscope optics unit 4, a plate 2 for fixing the sample to be analyzed, a spectrometer 5, and a Raman scattering light detection system 6. Figure 6 In the preferred embodiment, it also includes a stage 3 for fixing the plate 2 and an optical imaging element 11 for displaying and analyzing the field of view using images.

[0085] Furthermore, the micro Raman spectrometer of the present invention includes: a storage unit 7 for storing the number of laser irradiations and the Raman scattered light spectrum at that time; a calculation unit 81 for calculating the total scattering intensity of Raman scattered light in a specific wavenumber range under each laser irradiation; a calculation unit 82 for calculating the ratio of the total scattering intensity in the specific wavenumber range of each irradiation relative to the total scattering intensity in the specific wavenumber range of the first irradiation; a calculation unit 83 for calculating the correlation coefficient between the total scattering intensity in the specific wavenumber range of the first irradiation and the total scattering intensity in the specific wavenumber range under each irradiation number; and a display unit 9 for displaying the number of measurements and the total scattering intensity in the specific wavenumber range under each irradiation number. The analysis unit 10 determines the upper limit of the number of irradiations for which the analyte sample will not be damaged based on at least one of the relationships between the total scattering intensity, or the ratio of the total scattering intensity in the specific wavenumber range relative to the total scattering intensity in the first irradiation, and the relationship between the number of measurements and the correlation coefficient.

[0086] Laser source A is a source of laser light used to obtain the Raman scattered light.

[0087] The microscope optics section 4 can be exemplified by a structure in which an objective lens (not shown) composed of a combination of a convex lens and a concave lens is used as an objective lens optical element (not shown). Light incident on the microscope optics section 3 is focused onto the measurement object sample fixed on the plate 2 by these objective lens optical elements.

[0088] The Raman scattered light reflected from the sample is guided to the beam splitter 5 and the Raman scattered light detection system 6 via a condenser lens (not shown) and a focusing point (not shown). The Raman scattered light focused by the condenser lens is focused at the focusing point and guided to the beam splitter 5.

[0089] At this point, from the viewpoint of resolution, it is preferable that the microscope optics 4 is a confocal optical system in which the positions of the light source A, the plate 2, and the focusing point are in a conjugate relationship.

[0090] The optical imaging element 11 may include, for example, a charge-coupled device (CCD) image sensor or a complementary metal-oxide-semiconductor (CMOS) image sensor, configured to capture still or moving images of the sample. The optical imaging element can capture all or at least any of the following images of the sample: bright-field images, dark-field images, phase-contrast images, fluorescence images, polarized microscope images, etc., depending on the structure of the microscope optics 4 or the transmitted illumination (not shown). The optical imaging element may output the captured images to other information processing devices as needed.

[0091] The microscopic Raman spectrometer of the present invention includes a storage unit 7, which stores the number of times the laser light irradiates (n) and the Raman scattered light spectrum (Wn) at that time. The storage unit 7 is configured not only to store the values ​​of n and Wn, but also to be able to retrieve them when needed. Preferably, the storage unit 7 stores n and Wn as a set of data.

[0092] The micro Raman spectrometer of the present invention includes a calculation unit 81 that calculates the total scattering intensity Sn of Raman scattered light within a specific wavenumber range under each laser irradiation and is part of a calculation unit 8. The method for determining Sn is as described above, and the calculation unit 81 is configured to calculate Sn.

[0093] Furthermore, the micro Raman spectrometer of the present invention includes: determining the ratio s of Sn to S1. n The arithmetic unit 82, which is part of the arithmetic unit 8, and the arithmetic unit 83, which is part of the arithmetic unit 8, calculate the correlation coefficient r between S1 and Sn.

[0094] The arithmetic units 81 to 83 may be the same arithmetic device or they may be independent arithmetic devices.

[0095] s n The calculation methods for r are as described above.

[0096] Sn and s obtained in the arithmetic unit 8 n r can be sent to the storage unit 7 and stored. In the case of storage, it is preferable to store previously stored n, Sn, and s. n Stored in groups. Additionally, the stored Sn and s... n Preferably, it is configured to be retrieved when needed.

[0097] The Sn or s obtained in the calculation unit 8 n The relationship between the number of measurements n and at least one of the measurements n, and the relationship between n and r, are displayed on display unit 9. For example, the display method may include: relative to n, displaying the corresponding Sn or s...n And the method of displaying n and r as a group, relative to n, Sn or s n Methods such as displaying r as a group are preferred, as described above, where Sn or s is plotted relative to n. n To display, relative to n plot r.

[0098] For example, if the display is as follows Figure 4 or Figure 5 A diagram that illustrates this would be visually easy to understand and to determine the number of times the sample was damaged by laser light.

[0099] Furthermore, the micro Raman spectrometer of the present invention includes an analysis unit, which analyzes Sn or s obtained from the calculation unit 8. n The relationship between the number of measurements n and at least one of the measurements n, and the relationship between n and r, is used to determine the upper limit of the number of laser irradiations that will not damage the sample being analyzed.

[0100] The method for determining the upper limit of the number of laser irradiations that will not damage the sample in the analysis unit 10 is as described above. The obtained upper limit of the number of laser irradiations that will not damage the sample can be displayed on the display unit 9. For example, the range of the number of laser irradiations that will not damage the sample can be related to Sn or s displayed on the display unit 9. n The plots relative to n, or r relative to n, are displayed together.

[0101] As mentioned above, the range of laser irradiation times that can prevent damage to the analyte sample is related to Sn or s. n The plotting relative to n or the plotting of r relative to n are displayed together on the display unit 9, thereby allowing the range to be selected on the screen of the display unit 9.

[0102] By selecting a range on the screen of display unit 9, storage unit 7, display unit 9, and analysis unit 10 can be linked together to retrieve Wn from storage unit 7, which stores n and Raman scattering spectra Wn, corresponding to the range of n that was not damaged by laser light. The selection method can be set to automatically retrieve Raman scattering spectra from storage unit 7 below the upper limit of the number of times the sample was irradiated by laser light that did not damage it, as determined by analysis unit 10. Alternatively, the sample can be retrieved from storage unit 7 by the analyst specifying the range on the screen of display unit 9 using a mouse or keyboard.

[0103] When the range is selected by the analyst, it is not necessary to specify the (n-1)th time determined by the analysis unit 10; the range can be selected by the analyst's judgment.

[0104] By using the aforementioned micro Raman spectrometer, data of Raman scattered light obtained before the sample was damaged by laser light during Raman spectrometry can be identified, and the structural analysis of the sample can be performed solely based on this data of Raman scattered light before damage.

[0105] According to the Raman spectrophotometric analysis method of the present invention, it is possible to identify the Raman scattered light data obtained before the sample to be damaged by laser light during Raman spectrophotometric determination, and to perform structural analysis of the sample to be analyzed solely based on this Raman scattered light data before damage.

[0106] Furthermore, according to the present invention, a micro Raman spectrophotometer for performing the Raman spectrophotometric analysis method is provided.

[0107] [form]

[0108] It will be understood by those skilled in the art that the exemplary embodiments described are specific examples of the following forms.

[0109] [1] A Raman spectrophotometric analysis method

[0110] The laser light emitted from the laser source is projected onto the sample being analyzed through the objective lens optical elements.

[0111] Raman scattered light was obtained from the sample being analyzed.

[0112] The total scattering intensity within a specific wavenumber range is determined by spectroscopying the obtained Raman scattered light.

[0113] The process of repeatedly calculating the total scattering intensity within a specific wavenumber range based on the irradiation by the laser light is performed multiple times.

[0114] Calculate the ratio of the total scattered intensity in each specific wavenumber range of the irradiation to the total scattered intensity in the specific wavenumber range of the first irradiation.

[0115] Calculate the correlation coefficient between the total scattered intensity within the specific wavenumber range of the first irradiation and the total scattered intensity within the specific wavenumber range for each subsequent irradiation.

[0116] Based on at least one of the following relationships: the number of measurements and the total scattered intensity at each of the irradiation numbers, or the ratio of the total scattered intensity in the specific wavenumber range for each irradiation number to the total scattered intensity in the specific wavenumber range relative to the first irradiation; and

[0117] The relationship between the number of measurements and the correlation coefficient.

[0118] To determine the upper limit of the number of irradiations required to ensure the sample remains undamaged during analysis.

[0119] And use the data of Raman scattered light prior to the number of irradiations at the upper limit.

[0120] According to the invention described in [1], a Raman spectrophotometric analysis method is provided, which can identify the Raman scattered light data obtained before the sample to be analyzed is damaged by laser light during Raman spectrophotometric determination, and perform structural analysis of the sample to be analyzed based solely on the Raman scattered light data before the damage.

[0121] [2] According to the Raman spectrophotometric analysis method described in [1], wherein at least one of the number of measurements is plotted and the total scattering intensity at each of the irradiations, or the ratio of the total scattering intensity in the specific wavenumber range of each irradiation relative to the total scattering intensity in the specific wavenumber range of the first irradiation.

[0122] [3] According to the Raman spectrophotometric analysis method described in [1] or [2], wherein the number of measurements and the correlation coefficient are plotted.

[0123] [4] According to the Raman spectrophotometric analysis method described in [2], a linear regression analysis is performed on at least one of the plot of the number of measurements and the total scattering intensity at each of the irradiations, or the ratio of the total scattering intensity in the specific wavenumber range of each irradiation relative to the total scattering intensity in the specific wavenumber range of the first irradiation, and an upper limit of the number of irradiations at which the sample of analysis is not damaged is determined based on the number of measurements in which the slope changes.

[0124] [5] According to the Raman spectrophotometric analysis method described in [4], a linear regression analysis is performed on the plotting of the number of measurements and the correlation coefficient, and the upper limit of the number of irradiations without damage to the sample is determined based on the number of measurements in which the slope changes.

[0125] According to the invention described in [2] to [5], it is possible to more easily identify the data of Raman scattered light obtained before the sample of the analyte is damaged by laser light in Raman spectrometry.

[0126] Furthermore, those skilled in the art will understand that the exemplary embodiments described are specific examples of the following forms.

[0127] [6] A micro Raman spectrometer, comprising:

[0128] Laser source;

[0129] Microscope Optics;

[0130] A plate is used to fix the sample being analyzed.

[0131] A beam splitter and Raman scattering detection system, which features:

[0132] The storage section stores the number of laser irradiations and the Raman scattering spectrum at that time.

[0133] A computation unit that calculates the total scattering intensity of Raman scattered light within a specific wavenumber range under each laser irradiation;

[0134] A calculation unit that calculates the ratio of the total scattered intensity in each specific wavenumber range of irradiation, relative to the total scattered intensity in the specific wavenumber range of the first irradiation;

[0135] The computational unit calculates the correlation coefficient between the total scattering intensity in the specific wavenumber range for the first irradiation and the total scattering intensity in the specific wavenumber range for each irradiation cycle; and

[0136] The display unit shows the relationship between at least one of the number of measurements and the total scattering intensity at each of the irradiation numbers, or the ratio of the total scattering intensity in the specific wavenumber range for each irradiation number to the total scattering intensity in the specific wavenumber range for each irradiation number, relative to the total scattering intensity in the specific wavenumber range for the first irradiation, and...

[0137] The relationship between the number of measurements and the correlation coefficient; and

[0138] The analysis unit determines the relationship between at least one of the following: the number of measurements and the total scattering intensity at each of the irradiation numbers; or the ratio of the total scattering intensity in the specific wavenumber range for each irradiation number to the total scattering intensity in the specific wavenumber range relative to the first irradiation; and

[0139] The relationship between the number of measurements and the correlation coefficient is used to determine the upper limit of the number of irradiations required to ensure that the sample remains undamaged.

[0140] According to the invention described in [6], a micro Raman spectrometer is provided, which can identify the Raman scattered light data obtained before the sample to be analyzed is damaged by laser light in Raman spectrometry, and simply perform Raman spectrometry analysis on the sample to be analyzed based solely on the Raman scattered light data before the damage.

[0141] [7] According to the micro Raman spectrometer described in [6], the display unit plots and displays at least one of the number of measurements and the total scattering intensity at each of the irradiation numbers, or the ratio of the total scattering intensity at each of the irradiation numbers to the total scattering intensity at each of the irradiation numbers relative to the total scattering intensity at the first irradiation at the specific wavenumber range.

[0142] [8] According to the micro Raman spectrometer described in [6] or [7], wherein the display unit plots and displays the number of measurements and the correlation coefficient.

[0143] [9] The micro Raman spectrometer according to any one of [6] to [8], wherein the analysis unit performs linear regression analysis on at least one of the plot of the number of measurements and the total scattering intensity at each of the irradiation numbers, or the ratio of the total scattering intensity at each of the specific wavenumber ranges relative to the total scattering intensity at the first irradiation, to determine the upper limit of the number of irradiation numbers at which the sample to be analyzed is not damaged.

[0144]

[10] The micro Raman spectrometer according to any one of [6] to [9], wherein the analysis unit performs linear regression analysis on the plotting of the number of measurements and the correlation coefficient to determine the upper limit of the number of irradiations without damage to the sample to be analyzed.

[0145]

[11] The micro Raman spectrometer described in [6] to

[10] also has the function of retrieving and displaying the Raman scattering spectrum of the sample to be analyzed after a number of irradiations without damage from the storage unit.

[0146] According to the invention described in [7] to

[11] , a micro Raman spectrometer is provided that can more easily identify data of Raman scattered light obtained before the sample being damaged by laser light in Raman spectrometry.

[0147] [Explanation of Symbols]

[0148] 1: Micro Raman Spectrometer

[0149] 2: Board

[0150] 3: Platform

[0151] 4: Microscope Optical Section

[0152] 5: Spectrometer

[0153] 6: Raman scattering light detection system

[0154] 7: Storage Department

[0155] 8: Arithmetic Department

[0156] 81: Arithmetic Department

[0157] 82: Arithmetic Department

[0158] 83: Arithmetic Department

[0159] 9: Display Section

[0160] 10: Analysis Department

[0161] 11: Optical camera element

[0162] A: Laser light source.

Claims

1. A Raman spectrophotometric analysis method, wherein laser light emitted from a laser source is irradiated onto the sample to be analyzed by means of an objective lens optical element. Raman scattered light was obtained from the sample being analyzed. The total scattering intensity within a specific wavenumber range is determined by spectroscopying the obtained Raman scattered light. The process of repeatedly calculating the total scattering intensity within a specific wavenumber range based on the irradiation by the laser light is performed multiple times. Calculate the ratio of the total scattered intensity in each specific wavenumber range of the irradiation to the total scattered intensity in the specific wavenumber range of the first irradiation. Calculate the correlation coefficient between the total scattered intensity within the specific wavenumber range of the first irradiation and the total scattered intensity within the specific wavenumber range for each subsequent irradiation. Based on at least one of the following relationships: the number of measurements and the total scattered intensity at each of the irradiation numbers, or the ratio of the total scattered intensity in the specific wavenumber range for each irradiation number to the total scattered intensity in the specific wavenumber range relative to the first irradiation; and The upper limit of the number of irradiations required to prevent damage to the sample is determined based on the relationship between the number of measurements and the correlation coefficient. And use the data of Raman scattered light prior to the number of irradiations at the upper limit.

2. The Raman spectrophotometric analysis method according to claim 1, wherein, The plotting measurement number is at least one of the total scattering intensity at each of the irradiation numbers, or the ratio of the total scattering intensity in the specific wavenumber range of each irradiation number relative to the total scattering intensity in the specific wavenumber range of the first irradiation.

3. The Raman spectrophotometric analysis method according to claim 1, wherein, Plot the number of measurements against the correlation coefficient.

4. The Raman spectrophotometric analysis method according to claim 2, wherein, Linear regression analysis is performed on at least one of the plots of the number of measurements and the total scattering intensity at each of the irradiations, or the ratio of the total scattering intensity in the specific wavenumber range of each irradiation relative to the total scattering intensity in the specific wavenumber range of the first irradiation, and an upper limit of the number of irradiations without damage to the analyte sample is determined based on the number of measurements in which the slope changes.

5. The Raman spectrophotometric analysis method according to claim 3, wherein, Linear regression analysis was performed on the plot of the number of measurements and the correlation coefficient, and the upper limit of the number of irradiations without damage to the sample was determined based on the number of measurements in which the slope changed.

6. A micro Raman spectrometer, comprising: Laser source; Microscope Optics; A plate is used to fix the sample being analyzed. A beam splitter; and a Raman scattering light detection system, and it has the following features: The storage section stores the number of times the laser light irradiated the object and the Raman scattering spectrum at that time. A computation unit that calculates the total scattering intensity of Raman scattered light within a specific wavenumber range under each laser irradiation; A calculation unit that calculates the ratio of the total scattered intensity in each specific wavenumber range of irradiation, relative to the total scattered intensity in the specific wavenumber range of the first irradiation; A computational unit for calculating the correlation coefficient between the total scattered intensity in the specific wavenumber range of the first irradiation and the total scattered intensity in the specific wavenumber range for each irradiation number; as well as The display unit shows the relationship between at least one of the number of measurements and the total scattering intensity at each of the irradiation numbers, or the ratio of the total scattering intensity in the specific wavenumber range for each irradiation number to the total scattering intensity in the specific wavenumber range for each irradiation number, relative to the total scattering intensity in the specific wavenumber range for the first irradiation, and... The relationship between the number of measurements and the correlation coefficient; The analysis unit determines the relationship between at least one of the following: the number of measurements and the total scattering intensity at each of the irradiation numbers; or the ratio of the total scattering intensity in the specific wavenumber range for each irradiation number to the total scattering intensity in the specific wavenumber range relative to the first irradiation; and The relationship between the number of measurements and the correlation coefficient. To determine the upper limit of the number of irradiations required to ensure that the sample being analyzed is not damaged.

7. The micro Raman spectrometer according to claim 6, wherein, The display unit plots and displays at least one of the following: the number of measurements and the total scattering intensity for each of the irradiations, or the ratio of the total scattering intensity for each of the irradiations to the total scattering intensity in the specific wavenumber range relative to the first irradiation.

8. The micro Raman spectrometer according to claim 6, wherein, The display unit plots and displays the number of measurements and the correlation coefficient.

9. The micro Raman spectrometer according to claim 6, wherein, The analysis unit performs linear regression analysis on at least one of the plots of the number of measurements and the total scattering intensity at each of the irradiation numbers, or the ratio of the total scattering intensity at each of the irradiation numbers to the total scattering intensity at each of the irradiation numbers relative to the total scattering intensity at the first irradiation at the specified wavenumber range, to determine the upper limit of the number of irradiation numbers at which the sample to be analyzed can be irradiated without damage.

10. The micro Raman spectrometer according to claim 6, wherein, The analysis unit performs linear regression analysis on the plotting of the number of measurements and the correlation coefficient to determine the upper limit of the number of irradiations without damage to the sample being analyzed.

11. The micro Raman spectrometer according to claim 6 further has the function of retrieving and displaying the Raman scattering spectrum of the sample to be analyzed without damage from the storage unit.

Images