ICP emission spectrophotometer

Abstract

To enable a user to easily check to see whether or not an optical element is fouled in an ICP emission spectrophotometer.SOLUTION: Provided is an ICP emission spectrophotometer equipped with a plurality of optical elements, the ICP emission spectrophotometer including: a dirt determination unit 204 that compares the current emission spectrum obtained by measuring a prescribed sample with a contrast spectrum which is an emission spectrum obtained by measuring a sample of the same composition as the prescribed sample in the past, and determines whether or not any of the plurality of optical elements is fouled, on the basis of a degree of reduction in the intensity from the contrast spectrum to the current spectrum; and notification units 205, 212 that, when it is determined that fouling is found, notify a user of the fouling. The dirt determination unit 204 determines that one of the plurality of optical elements is fouled when the degree of reduction is larger on a short wavelength side than on a long wavelength side in a predetermined wavelength range.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an ICP (Inductively Coupled Plasma) optical emission spectrometer. [Background technology]

[0002] In an ICP optical emission spectrometer, a liquid sample is introduced into a nebulizer, and the liquid sample is atomized by argon gas supplied to the nebulizer. The atomized sample is mixed with argon gas and sent to a plasma torch. Then, high-frequency power is supplied to an induction coil disposed around the periphery of the plasma torch to turn the gas introduced into the torch into a plasma state. When the atomized sample passes through the plasma flame, the molecules or atoms of the sample are heated and excited to emit light. This emitted light is extracted, dispersed by a spectroscope, and detected by a detector to obtain an emission spectrum. Qualitative analysis of the elements contained in the sample is performed from the wavelengths of the spectral lines (brightness spectrum) appearing in the emission spectrum, and quantitative analysis of the elements is performed from the intensity of the spectral lines.

[0003] Such an ICP optical emission spectrometer is provided with a reflector (hereinafter referred to as an external mirror) that guides light from the plasma flame to the spectrometer, a transmission window for introducing the light into the spectrometer, and multiple optical elements such as a reflector, a prism, or a diffraction grating housed in the spectrometer (see, for example, Patent Document 1). These optical elements gradually become dirty over time, and as a result, the light reaching the detector is attenuated, making it impossible to perform measurements with sufficient sensitivity.

[0004] Therefore, conventionally, the degree of dirt on the optical elements installed in an ICP optical emission spectrometer (hereinafter sometimes simply referred to as the device) has been checked according to the following procedure. (1) Immediately after the installation of the equipment, the manufacturer's installation staff measures a specified sample (evaluation sample) and stores the obtained emission spectrum as control data in a personal computer or the like attached to the equipment. (2) At any time, the user measures the same evaluation sample under the same conditions as those immediately after installation, and compares the obtained emission spectrum with the control data to determine whether the optical element is contaminated. (3) If the optical elements are determined to be dirty, the user cleans (wipes) the external mirror and the transmission window. (4) After cleaning, the evaluation sample is measured again, and the obtained emission spectrum is compared with the control data, allowing the user to determine whether the contamination of the optical element has been eliminated. (5) If it is determined that the dirt has not been eliminated, it is assumed that the optical elements inside the spectrometer are dirty and a maintenance request is made to the manufacturer. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2007-322261 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the conventional method, the user must visually compare the emission spectrum (the control data) obtained by measuring the evaluation sample immediately after the installation of the device with the emission spectrum obtained by measuring the evaluation sample at the arbitrary timing, and determine whether or not the optical element is dirty based on the difference between the two. In addition, the measurement results (emission spectrum) of the ICP optical emission spectrometer may vary due to various factors other than the dirt on the optical element. Therefore, it is difficult for an inexperienced user to correctly determine whether or not the optical element is dirty using the conventional method.

[0007] The present invention has been made in consideration of the above points, and an object of the present invention is to enable a user to easily know whether or not an optical element in an ICP optical emission spectrometer is dirty. [Means for solving the problem]

[0008] The ICP optical emission spectrometer according to the present invention, which has been made to solve the above problems, is an analysis unit having a light-emitting unit that excites components in the sample liquid to emit light by atomizing the sample liquid and introducing it into a plasma flame, a spectroscope that wavelength-disperses the emitted light from the plasma flame, a photodetector that detects the wavelength-dispersed emitted light, and a plurality of optical elements arranged on an optical path from the plasma flame to the photodetector; a spectrum generating unit that generates an emission spectrum based on a detection signal from the photodetector; a contamination determination unit that compares a determination spectrum, which is a current emission spectrum obtained by measuring a specific sample with the analysis unit, with a control spectrum, which is an emission spectrum obtained by measuring the same sample in the past with the analysis unit, and determines whether or not contamination has occurred in any of the plurality of optical elements based on the degree of decrease in intensity of the determination spectrum from the intensity of the control spectrum; a notification unit that notifies a user when it is determined that the stain has occurred; having The dirt determination unit determines that dirt has occurred in any of the plurality of optical elements when the degree of decrease is greater on the short wavelength side than on the long wavelength side within a predetermined wavelength range. Effect of the Invention

[0009] According to the ICP optical emission spectrometer of the present invention having the above-mentioned configuration, the user can easily know whether or not the optical element is dirty. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram showing the overall configuration of an ICP optical emission spectrometer according to one embodiment of the present invention. [Diagram 2] 11 is a first half of a flowchart showing a procedure for determining whether or not dirt has occurred on an optical element in the embodiment. [Diagram 3] The latter half of the flowchart. [Figure 4] FIG. 4 is a diagram showing an example of a notification screen displayed on a display unit in the embodiment. [Diagram 5] FIG. 2 is a diagram showing the overall configuration of an ICP optical emission spectrometer according to another embodiment of the present invention. [Figure 6] 13 is a graph showing the wavelength dependence of the intensity ratio of the emission spectra in a test example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a diagram showing the overall configuration of an ICP optical emission spectroscopic analyzer (hereinafter, sometimes simply referred to as "the apparatus") according to this embodiment. This apparatus is roughly divided into an analysis section 100 and a control / processing section 200. The analysis section 100 includes a light emitting section 110, a light guiding section 120, and a spectroscope 130.

[0012] In the light emission unit 110, the sample solution contained in the sample container 111 is sucked by a pump (not shown) or naturally sucked by the structure of the nebulizer, and then sprayed from the nebulizer 112 into the spray chamber 113. The atomized sample is introduced into the plasma torch 115 together with argon (Ar) gas supplied as a carrier gas from the gas supply unit 114. The plasma torch 115 is equipped with a quartz tube having a triple-tube structure and an induction coil 116 wound around its outer periphery, and the sample and carrier gas are supplied to the innermost tube of the triple tube. In addition, Ar gas as a plasma gas (coolant gas) and Ar gas as an auxiliary gas are supplied from the gas supply unit 114 to the outermost tube and the middle tube of the triple tube, respectively, at different flow rates. Furthermore, a high-frequency current is supplied from a high-frequency power source 117 to the induction coil 116 of the plasma torch 115, and a high-temperature plasma flame 118 is formed from the Ar gas by the action of the high-frequency magnetic field generated by this. When a sample is introduced into this plasma flame 118, the components of the sample are atomized and excited, generating light of a wavelength specific to the component.

[0013] Light guiding unit 120 has a cylindrical housing (hereinafter referred to as light guiding unit housing 121) that covers the optical path from plasma flame 118 to spectrometer 130. In the example of Fig. 1, light guiding unit 120 has an optical path that extracts emitted light in the axial direction of plasma flame 118 (upward in Fig. 1). That is, a fixed mirror 122 is disposed inside light guiding unit housing 121 that guides the emitted light to spectrometer 130 by bending the optical path of the emitted light extracted upward at a substantially right angle.

[0014] The configuration of light guiding section 120 is not limited to that shown in FIG. 1, and various configurations can be adopted (details will be described later).

[0015] The spectroscope 130 has a substantially sealed housing 131 and an entrance window 132 for taking in the light guided by the light guide unit 120 into the housing 131. Inside the housing 131, a toroidal mirror 139, a plane mirror 140, a slit plate 141, a collimator mirror 133, an echelle diffraction grating 134, a prism 135, a Schmidt mirror 136, a telemeter mirror 137, and a photodetector 138 are arranged along an optical path. The light that enters the housing 131 from the entrance window 132 is collected by the toroidal mirror 139, and its optical path is bent at a substantially right angle. The light collected and reflected by the toroidal mirror 139 has its optical path further bent at a substantially right angle by the plane mirror 140, and is irradiated onto the slit plate 141. The light passes through a slit formed in the slit plate 141, passes through the collimator mirror 133, and is two-dimensionally wavelength-dispersed by the echelle diffraction grating 134 and the prism 135, and is introduced into the photodetector 138 via the Schmidt mirror 136 and the telemeter mirror 137. As the photodetector 138, for example, a two-dimensional detector such as a CCD image sensor can be used. A detection signal by the photodetector 138 is converted into digital data by the A / D converter 142 and sent to the control / processing unit 200.

[0016] Hereinafter, fixed mirror 122, entrance window 132, toroidal mirror 139, plane mirror 140, collimator mirror 133, echelle diffraction grating 134, prism 135, Schmidt mirror 136, and telemeter mirror 137 may be collectively referred to as "optical elements".

[0017] The spectrometer 130 is not limited to the structure shown in FIG. 1 (that is, the Echelle type), and may be, for example, a Paschen-Runge type or a Czerny-Turner type.

[0018] The control / processing unit 200 includes a spectrum generating unit 201 that processes the above-mentioned digital data to generate an emission spectrum, a spectrum storage unit 202 that stores the emission spectrum obtained by the spectrum generating unit 201, an analysis control unit 203 that controls the operation of each unit of the analysis unit 100 (e.g., the high-frequency power supply 117 and the gas supply unit 114, etc.), a contamination determination unit 204 (details will be described later) that determines whether or not an optical element included in the analysis unit 100 is contaminated, a display control unit 205 that controls a display unit 212 described later, and an improvement rate storage unit 207. The contamination determination unit 204 includes an improvement rate specifying unit 206. Details of the contamination determination unit 204, the improvement rate specifying unit 206, and the improvement rate storage unit 207 will be described later.

[0019] The functions of the control / processing unit 200 are realized by a computer including a CPU, a memory, and a large-capacity storage medium (such as a hard disk). The computer may be a dedicated computer built into the main body of the ICP optical emission spectrometer, but typically a personal computer or the like is used. A predetermined program is installed in the computer in advance, and the functions of the spectrum generating unit 201, the analysis control unit 203, the dirt determining unit 204, the improvement rate identifying unit 206, and the display control unit 205 described above are realized in software by the CPU executing this program. In addition, the functions of the spectrum storage unit 202 and the improvement rate storage unit 207 are realized by the large-capacity storage medium. The computer is connected to an operation unit 211 for a user to input various instructions and a display unit 212 for displaying various information. The display unit 212 is, for example, a liquid crystal display, and the operation unit 211 is, for example, a keyboard, a pointing device such as a mouse, or a touch panel attached to the display unit 212. The display control unit 205 and the display unit 212 in this embodiment correspond to the "notification unit" in the present invention.

[0020] The characteristic operations of the device according to this embodiment will now be described.

[0021] In the apparatus according to this embodiment, first, at a time when the above-mentioned multiple optical elements are considered to be free of contamination (for example, immediately after the installation of the apparatus or immediately after maintenance by the manufacturer), a predetermined sample is measured by the analysis unit 100 by a user or a person in charge of the manufacturer, and the emission spectrum generated by the spectrum generation unit 201 through the measurement is called a control spectrum S A The spectrum is stored in the spectrum storage unit 202 as a spectrum. Note that it is desirable to use, as the predetermined sample, one having bright lines in both the long wavelength region and the short wavelength region (details will be described later) of the wavelength range used for the determination in the dirt determination unit 204. Note that in this embodiment, a sample for wavelength calibration (hereinafter referred to as a "calibration sample") is used as the predetermined sample.

[0022] Thereafter, every time the wavelength calibration of the device is performed, the contamination determination unit 204 automatically (i.e., without the user giving any explicit instruction) determines whether the optical element is contaminated. The procedure for this determination will be described with reference to the flowcharts of FIG. 2 and FIG. 3. Specifically, first, the user determines whether the calibration sample (control spectrum S A The operator sets a sample for calibration (having the same composition as the sample used to obtain the reference spectrum S) in the analysis unit 100 and instructs the operation unit 211 to perform wavelength calibration. A The measurement is performed under the same measurement conditions as when the calibration sample was acquired. As a result, the calibration sample is measured in the analysis unit 100 under the control of the analysis control unit 203 (Yes in step 301), and an emission spectrum, which is the measurement result of the calibration sample, is generated in the spectrum generation unit 201. Then, wavelength calibration is performed based on the emission spectrum, and the emission spectrum is stored in the spectrum storage unit 202 (hereinafter, this emission spectrum is referred to as the "spectrum for determination S"). B The details of wavelength calibration are not directly related to the present invention, so a detailed explanation is omitted here.

[0023] Next, the dirt determination unit 204 detects the determination spectrum S B and the above-mentioned control spectrum S A The present inventors read out the spectrum S from the spectrum storage unit 202 (step 302), and judge whether any of the plurality of optical elements is dirty based on these spectra. If any of the plurality of optical elements is dirty, the present inventors read out the control spectrum S A The intensity of the spectrum S is compared to the B It was found that the intensity of the light decreases, and the degree of the decrease increases from the long wavelength side to the short wavelength side. Based on this finding, the dirt determination unit 204 determines whether or not dirt has occurred on any of the plurality of optical elements.

[0024] Specifically, first, the dirt determination unit 204 calculates the determination spectrum S B and contrast spectrum S AData in a predetermined wavelength range is extracted from each of the above. As the wavelength range, it is desirable to use a region with as short wavelengths as possible within the wavelength range that can be measured by the analysis unit 100. As such a wavelength range, for example, a wavelength range of 130 nm to 900 nm (preferably 130 nm to 650 nm, more preferably 130 nm to 400 nm) can be used. As the wavelength range, it is desirable not to use a wavelength range that is easily affected by impurities contained in the calibration sample (for example, minerals contained in trace amounts in pure water) (for example, near 393.366 nm and near 396.847 nm when calcium is contained as an impurity).

[0025] And the control spectrum S A The judgement spectrum S for B It is determined whether the degree of decrease is greater on the short wavelength side than on the long wavelength side in the wavelength range (step 303). The short wavelength side means a wavelength range less than a predetermined reference wavelength in the wavelength range, and the long wavelength side means a wavelength range equal to or greater than the reference wavelength in the wavelength range. Here, the reference wavelength can be any wavelength within a range of 130.1 nm to 700 nm (preferably 150 nm to 450 nm, more preferably 150 nm to 300 nm). In the following, the case where the degree of decrease is greater on the short wavelength side than on the long wavelength side in the wavelength range is referred to as "reaching the dirt determination standard", and the case where this is not the case is referred to as "not reaching the dirt determination standard".

[0026] In step 303, the spectrum for judgment S B A method for determining whether the stain level reaches the stain criterion is, for example, as follows.

[0027] First, the control spectrum S at a predetermined wavelength on the short wavelength side is A The spectrum S for determining the intensity of B Hereinafter, this ratio is referred to as the intensity ratio (B1 / A1) on the short wavelength side. Similarly, the intensity ratio of the control spectrum S at a predetermined wavelength on the long wavelength side is calculated.A Determination spectrum S for the intensity of B Obtain the ratio of the intensities of. Hereinafter, this ratio is referred to as the intensity ratio on the long-wavelength side (B2 / A2). For a plurality of predetermined wavelengths on the short-wavelength side, the control spectrum S A Determination spectrum S for the intensity of B Obtain the ratio of the intensities of, and the representative value (for example, the average value or the median value, the same hereinafter) of the obtained plurality of ratio values may be used as the intensity ratio on the short-wavelength side (B1 / A1). Similarly, for a plurality of predetermined wavelengths on the long-wavelength side, the control spectrum S A Determination spectrum S for the intensity of B Obtain the ratio of the intensities of, and the representative value of the obtained plurality of ratio values may be used as the intensity ratio on the long-wavelength side (B2 / A2).

[0028] And the intensity ratio on the short-wavelength side (B1 / A1) is less than 1, the intensity ratio on the short-wavelength side (B1 / A1) is less than the intensity ratio on the long-wavelength side (B2 / A2) (that is, B1 / A1 < B2 / A2), and moreover, the difference between the intensity ratio on the long-wavelength side (B2 / A2) and the intensity ratio on the short-wavelength side (B1 / A1) is a predetermined threshold value T V or more (that is, (B2 / A2 - B1 / A1) ≧ T V ), in this case, it is determined that the determination spectrum S B has reached the dirt determination criterion. The threshold value T V For example, the user can set a predetermined value, for example, any value in the range of 0.1 to 0.7 (more preferably, any value in the range of 0.3 to 0.5).

[0029] However, the method for determining whether or not the determination spectrum S B has reached the dirt determination criterion is not limited to the above, and as long as it can determine whether the degree of decrease of the determination spectrum S A with respect to the control spectrum S B is greater on the short-wavelength side than on the long-wavelength side within the wavelength range, it can be any method.

[0030] For example, the ratio of the intensity ratio (B2 / A2) on the long wavelength side to the intensity ratio (B1 / A1) on the short wavelength side is calculated, and the intensity ratio (B1 / A1) on the short wavelength side is smaller than 1 and the value is equal to or smaller than a predetermined threshold value T W (i.e., (B2 / A2) / (B1 / A1)≧T W ), the judgment spectrum S B It may be determined that the control spectrum S reaches the contamination criterion. A The spectrum S for determining the intensity of B The intensity ratio (S B / S A ), and an approximate curve is obtained. The slope of the approximate curve at a predetermined wavelength (for example, any one point in the range of 130 nm to 900 nm (preferably 130 nm to 400 nm)) is determined to be equal to or smaller than a predetermined threshold T X In addition, S in the entire wavelength range (or a part of the wavelength range including the predetermined wavelength) B / S A If the value of is smaller than 1, the judgment spectrum S B Alternatively, it may be determined that the stain determination criterion is reached when the slope of a straight line connecting a predetermined point on the long wavelength side and a predetermined point on the short wavelength side in the graph or the approximation curve is greater than or equal to a predetermined threshold value T Y If it is equal to or greater than this, the judgment spectrum S B Alternatively, it may be determined that the control spectrum S on the short wavelength side reaches the contamination criterion. A Intensity and judgment spectrum S B The difference between the intensity of the reference spectrum S on the long wavelength side (A1-B1) and the intensity of the reference spectrum S on the long wavelength side A Intensity and judgment spectrum S B The difference (A2-B2) between the intensity of the first and second values ​​is calculated, and if both the first and second values ​​are positive and the value obtained by dividing the first by the second ((A1-B1) / (A2-B2)) is equal to or smaller than a predetermined threshold value T Z If it is equal to or greater than this, the judgment spectrum S BIt may be determined that the stain has reached the stain determination standard.

[0031] The judgment spectrum S B If the amount of dirt does not reach the dirt determination criterion (No in step 303), the dirt determination unit 204 determines that the dirt is not present, and ends the series of processes related to the dirt determination of the optical element.

[0032] On the other hand, the judgment spectrum S B When the dirt determination criterion is reached (when the result is Yes in step 303), the dirt determination unit 204 determines that dirt has occurred in any of the plurality of optical elements (step 304). Then, the display control unit 205 displays a predetermined notification screen on the display unit 212 to notify the user of the device according to this embodiment that the optical element is dirty and the maintenance method that the user should perform (step 305). The maintenance method is to clean (wipe clean) or replace those of the plurality of optical elements that can be maintained by the user. Note that, among the plurality of optical elements, those that can be maintained by the user refer to, for example, optical elements (in this embodiment, the fixed mirror 122) that are arranged under the atmosphere (i.e., outside the spectrometer 130) that can be cleaned or replaced by the user, or a part of an optical element that is arranged at the boundary between the vacuumed space and the atmosphere and faces the atmosphere (in this embodiment, the surface of the entrance window 132 located outside the spectrometer 130) that can be cleaned by the user. In addition, even if an optical element is placed in the atmosphere, if it is easily scratched, such as a surface reflector, and the user cannot replace it, it does not fall under the above-mentioned category of "items that can be maintained by the user."

[0033] An example of a notification screen displayed on the display unit 212 in step 305 is shown in Fig. 4. In addition to a message indicating that the optical system (optical element) is dirty and indicating a method of maintenance that the user should perform, this notification screen has a "Maintenance Complete" button 401. After the user performs maintenance according to the message, the user presses the "Maintenance Complete" button 401 by performing a predetermined operation on the operation unit 211, and the control / processing unit 200 is notified that the maintenance by the user (hereinafter referred to as "user maintenance") has been completed (i.e., step 306 becomes Yes). Here, the display unit 212, the operation unit 211, and the display control unit 205 cooperate to function as a "maintenance completion input receiving unit" in the present invention.

[0034] When the control / processing unit 200 is notified of the completion of the user maintenance, the analysis control unit 203 controls the analysis unit 100 to execute a remeasurement of the calibration sample contained in the sample container 111 (step 307), and the spectrum generating unit 201 generates an emission spectrum (hereinafter, "spectrum for re-determination S") as a result of the remeasurement. C ") is generated and stored in the spectrum storage unit 202. Note that the remeasurement is performed using a control spectrum S A and the judgment spectrum S B The measurement shall be performed under the same conditions as when the measurement was taken.

[0035] Next, the improvement rate specifying unit 206 determines the re-evaluation spectrum S C and the above-mentioned judgment spectrum S B The spectrum storage unit 202 reads out the spectrum S and the spectrum S at one wavelength in the wavelength range, and compares the two to determine the improvement rate of the dirt on the optical element due to the user maintenance (step 309). C Intensity and judgment spectrum S B (or the ratio of the intensity of the re-evaluation spectrum S C Intensity and judgment spectrum SB (representative value of the ratio of the intensity of the spectrum S B The re-evaluation spectrum S when the intensity is set to 100 (or 1) C The improvement rate identified in step 309 is stored in the improvement rate storage unit 207 as the improvement rate due to the current user maintenance.

[0036] Next, the dirt determination unit 204 reads out from the improvement rate storage unit 207 the value of the improvement rate due to the current user maintenance and the value of the improvement rate that was specified in the same manner as above when the most recent user maintenance was performed in the past and stored in the improvement rate storage unit 207 (hereinafter referred to as the "improvement rate due to the previous user maintenance"). Then, if the improvement rate due to the current user maintenance is higher than the improvement rate due to the previous user maintenance, or if the improvement rate due to the current user maintenance is lower than the improvement rate due to the previous user maintenance but the degree of the decrease (for example, the difference between the improvement rate in the previous and current user maintenance) is lower than a predetermined threshold value T U If it is smaller than (that is, if No in step 310), the dirt determining unit 204 determines that the dirt on the optical element has been eliminated by user maintenance, and ends the series of processes.

[0037] On the other hand, the improvement rate due to the current user maintenance is lower than the improvement rate due to the previous user maintenance, and the degree of the decrease is smaller than a predetermined threshold T U If this is the case (i.e., if Yes in step 310), the dirt determination unit 204 determines that the dirt has not been sufficiently eliminated even by user maintenance, that is, that dirt has accumulated in an optical element that cannot be user-maintained (step 311). Then, the display control unit 205 displays a predetermined notification screen on the display unit 212 (step 312). The notification screen displays, for example, a message indicating that the optical element that cannot be user-maintained is dirty (or an error code indicating that), and a message urging the user to request maintenance from the manufacturer.

[0038] In this embodiment, in step 310, the improvement rate by the current user maintenance is compared with the improvement rate by the previous user maintenance to determine whether dirt has accumulated on the optical element that cannot be user-maintained. However, instead of this, the improvement rate by the current user maintenance is compared with a predetermined threshold T S In this case, for example, the improvement rate by the user maintenance may be compared with the threshold value T S If the contrast spectrum S at one wavelength in the wavelength range is less than or equal to the reference spectrum S at one wavelength in the wavelength range, it can be determined that dirt has accumulated in the optical element that cannot be maintained by the user. A Intensity and judgment spectrum S B The difference between the intensity of the reference spectrum S at the same wavelength (AB) A Intensity and re-evaluation spectrum S C The difference (AC) between the intensity of the AB and the intensity of the AC is calculated, and the ratio ((AC) / (AB)) is calculated as the improvement rate. The improvement rate is then set to a predetermined threshold T R The determination in step 310 above may be made by comparing with

[0039] In this way, in the device according to this embodiment, the current emission spectrum obtained by measuring the calibration sample (the determination spectrum S B ) and the emission spectrum obtained by measuring a sample having the same composition as the calibration sample in the past (control spectrum S A), the device automatically determines whether the optical element is dirty or not, so even an inexperienced user can accurately and easily know whether the optical element is dirty or not. In addition, if the optical element is dirty, the user is notified of the method of user maintenance, and if the remeasurement after the user maintenance determines that the improvement rate of the dirt is low, the user is notified of a message urging the user to request maintenance from the manufacturer, so that the user can easily know what action to take without referring to a manual or the like. Furthermore, in the device according to this embodiment, even if the user does not explicitly instruct the device to determine whether the optical element is dirty or not, the determination is automatically made every time wavelength calibration is performed, so that the burden on the user regarding the maintenance and management of the device can be reduced.

[0040] Although the embodiment of the present invention has been described above with specific examples, the present invention is not limited to the above embodiment, and appropriate modifications are permitted within the scope of the present invention. For example, in the above embodiment, it is assumed that the determination of whether the optical element is dirty is performed automatically every time the wavelength calibration of the device is performed, but instead, it may be determined whether the optical element is dirty in response to an explicit instruction from the user. In this case, the sample (the "predetermined sample" in the present invention) measured to obtain the determination spectrum and the re-determination spectrum does not necessarily have to be a calibration sample. Also, in the above embodiment, it is assumed that the re-measurement and re-determination of the dirt on the optical element are automatically performed by the user pressing the "Maintenance Complete" button 401, but instead, the re-measurement and re-determination may be performed in response to an explicit instruction from the user.

[0041] Further, the device according to the above embodiment includes the improvement rate specifying unit 206 and the improvement rate storage unit 207, but may be configured not to include these. In that case, instead of the processes of steps 308 to 310 described above, the dirt determining unit 204 determines the re-determination spectrum S C and the above-mentioned control spectrum S Aand are read out from the spectrum storage unit 202, and the two are compared to obtain a re-determination spectrum S C It may be possible to determine whether the re-evaluation spectrum S satisfies the contamination evaluation criterion. C If the spectrum for reassessment S satisfies the contamination judgment criterion, the contamination judgment unit 204 judges that the improvement of contamination by user maintenance is insufficient (hence, contamination has accumulated in an optical element that cannot be maintained by the user), and notifies the user by the display control unit 205 to request maintenance from the manufacturer. C The method of determining whether the spectrum S satisfies the contamination determination criterion is as follows: B Since this method is similar to the method for determining whether or not the stain criterion is satisfied, the explanation will be omitted here.

[0042] In the above embodiment, the light guide 120 forms an optical path that extracts only the emitted light in the axial direction of the plasma flame 118 (hereinafter referred to as the vertical direction), but is not limited thereto. Alternatively, the light guide 120 may form an optical path that extracts only the emitted light in the direction perpendicular to the axial direction of the plasma flame 118 (hereinafter referred to as the horizontal direction), or may simultaneously form an optical path that extracts the emitted light in the vertical direction and an optical path that extracts the emitted light in the horizontal direction, or may alternatively form either of the two optical paths. FIG. 5 shows a configuration example in which the present invention is applied to an ICP optical emission spectrometer equipped with a light guide configured to alternatively form either of the two optical paths. In this figure, the same or corresponding components as those shown in FIG. 1 are assigned reference numerals with the same last three digits, and the description will be omitted as appropriate. In this ICP optical emission spectrometer, a first fixed mirror 1122 that bends the optical path of the emitted light extracted vertically at a substantially right angle, a second fixed mirror 1123 that bends the optical path of the emitted light extracted horizontally at a substantially right angle, and a movable mirror 1124 that selectively guides either the light reflected by the first fixed mirror 1122 or the light reflected by the second fixed mirror 1123 to the spectrometer 1130 are arranged inside the light guide housing 1121. A half mirror may be used instead of the movable mirror 1124. In addition, the ICP optical emission spectrometer according to the present invention may be an ICP optical emission spectrometer equipped with a light guide having any of the above configurations, in which at least a part of the optical path from the plasma flame 118, 1118 to the spectrometer 130, 1130 is replaced with a light guide material such as an optical fiber. EXAMPLES

[0043] Test examples conducted to confirm the effects of the present invention will now be described.

[0044] In this test example, an ICP optical emission spectrometer having a configuration similar to that shown in FIG. 5 was used, and a control spectrum S was obtained by measuring a given sample in a state where the optical elements inside and outside the spectrometer 1130 were free of dirt. A Then, the predetermined sample is measured in a state where the optical elements inside and outside the spectroscope 1130 are dirty, to obtain a spectrum for determination S BAfter that, the optical elements outside the spectroscope 1130 (mirrors 1122 to 1124 of the light guide 1120 and the outer surface of the entrance window 1132) are cleaned by user maintenance, and the predetermined sample is measured to obtain a reassessment spectrum S C was obtained.

[0045] Figure 6 shows the control spectrum S A The spectrum S for determining the intensity of B A graph showing the ratio of the intensities of (solid line) vs. wavelength, and a reference spectrum S A Spectrum S for re-evaluation of the intensity of C The graph (dotted line) shows the relationship between the intensity ratio of the reference spectrum S and the wavelength. In this figure, the horizontal axis shows the wavelength, and the vertical axis shows the reference spectrum S. A The spectrum S for determining the intensity of B or spectrum S for re-determination C The intensity ratio is shown as a percentage.

[0046] As is clear from the solid line graph in the same figure, when the optical elements inside and outside the spectroscope 1130 are dirty, the judgment spectrum S B The intensity of the control spectrum S A The intensity of the spectrometer 1130 was lower than that of the spectrometer 1130, and the decrease was more noticeable on the short wavelength side (e.g., in the range below 400 nm) than on the long wavelength side (e.g., in the range of 400 nm or more) in the wavelength range of the graph (approximately 170 nm to 770 nm). As is clear from the dotted line graph in the same figure, in the state after user maintenance (i.e., the optical elements outside the spectrometer 1130 were not dirty, but the optical elements inside the spectrometer 1130 were dirty), the decrease was somewhat recovered, but the decrease was still greater on the short wavelength side than on the long wavelength side.

[0047] From this, it was confirmed that, like the ICP optical emission spectrometer of the present invention, it is possible to determine whether or not an optical element is dirty by comparing a determination spectrum, which is the current emission spectrum obtained by measuring a specified sample, with a control spectrum, which is an emission spectrum obtained in the past by measuring a sample of the same composition as the specified sample, and determining whether or not the degree of decrease in intensity of the determination spectrum from the intensity of the control spectrum is greater on the short wavelength side than on the long wavelength side within a predetermined wavelength range.

[0048] [Aspects] It will be apparent to those skilled in the art that the above-described exemplary embodiments are illustrative of the following aspects.

[0049] (Item 1) An ICP optical emission spectrometer according to one aspect of the present invention comprises: an analysis unit having a light-emitting unit that excites components in the sample liquid to emit light by atomizing the sample liquid and introducing it into a plasma flame, a spectroscope that wavelength-disperses the emitted light from the plasma flame, a photodetector that detects the wavelength-dispersed emitted light, and a plurality of optical elements arranged on an optical path from the plasma flame to the photodetector; a spectrum generating unit that generates an emission spectrum based on a detection signal from the photodetector; a contamination determination unit that compares a determination spectrum, which is a current emission spectrum obtained by measuring a specified sample in the analysis unit, with a control spectrum, which is an emission spectrum obtained by measuring a sample having the same composition as the specified sample in the past in the analysis unit, and determines whether or not contamination has occurred in any of the plurality of optical elements based on the degree of decrease in intensity of the determination spectrum from the intensity of the control spectrum; a notification unit that notifies a user when it is determined that the stain has occurred; having The dirt determination unit determines that dirt has occurred in any of the plurality of optical elements when the degree of decrease is greater on the short wavelength side than on the long wavelength side within a predetermined wavelength range.

[0050] According to the ICP optical emission spectrometer of paragraph 1, the device automatically determines whether or not the optical elements are contaminated based on the determination spectrum, which is the current emission spectrum obtained by measuring a specified sample, and the control spectrum, which is the emission spectrum obtained in the past by measuring a sample of the same composition as the specified sample, so that even an inexperienced user can accurately and easily know whether or not the optical elements are contaminated.

[0051] (2) The ICP optical emission spectrometer according to the second paragraph is an ICP optical emission spectrometer according to the first paragraph, The predetermined wavelength range includes at least a part of the range from 130 nm to 400 nm.

[0052] According to the ICP optical emission spectrometer according to the second aspect, it is possible to more appropriately determine whether or not any of the plurality of optical elements is soiled.

[0053] (3) The ICP optical emission spectrometer according to the third paragraph is an ICP optical emission spectrometer according to the first or second paragraph, The contamination determination unit calculates a short wavelength side intensity ratio, which is the ratio of the intensity of the determination spectrum to the intensity of the control spectrum on the shorter wavelength side than a reference wavelength defined in the wavelength range, and a long wavelength side intensity ratio, which is the ratio of the intensity of the determination spectrum to the intensity of the control spectrum on the longer wavelength side that is equal to or greater than the reference wavelength, and determines that the contamination has occurred if the short wavelength side intensity ratio is smaller than the long wavelength side intensity ratio and the difference between the two is equal to or greater than a predetermined threshold value.

[0054] According to the ICP optical emission spectrometer according to the third aspect, it is possible to more appropriately determine whether or not any of the plurality of optical elements is contaminated.

[0055] (4) The ICP optical emission spectrometer according to the 4th aspect is an ICP optical emission spectrometer according to any one of the 1st to 3rd aspects, When the dirt determination unit determines that the dirt has occurred, The notification section further notifies the user of a message urging the user to perform predetermined maintenance on those optical elements among the plurality of optical elements that can be maintained by the user.

[0056] According to the ICP optical emission spectrometer of paragraph 4, if the optical element is dirty, the user is notified of the maintenance method that can be performed, so that the user can easily know what action to take without having to refer to a manual, etc.

[0057] (5) The ICP optical emission spectrometer according to 5 is an ICP optical emission spectrometer according to 4, a maintenance completion input receiving unit that receives an input from a user indicating that the maintenance has been completed; an analysis control unit that controls the analysis unit to perform remeasurement of the predetermined sample when the maintenance completion input reception unit receives the input; and After performing said remeasurement, the dirt determination unit determines whether or not dirt has accumulated in an optical element that cannot be maintained by a user among the plurality of optical elements by comparing a re-determination spectrum, which is an emission spectrum acquired by the re-measurement, with the control spectrum or the determination spectrum, or both; When it is determined that dirt has accumulated on the optical element that cannot be maintained by the user, the notification unit notifies the user that maintenance by the manufacturer is required.

[0058] According to the ICP atomic emission spectrometer of paragraph 5, if it is determined from the comparison result between the re-evaluation spectrum and the control spectrum and / or the evaluation spectrum that dirt has accumulated in an optical element that cannot be maintained by the user, the user is notified that he or she should request maintenance from the manufacturer, so that the user can easily know what action he or she should take without having to refer to a manual, etc. [Explanation of symbols]

[0059] 100…Analysis Department 110…Light emitting part 115...Plasma torch 116…Induction coil 118...Plasma flame 120...Light guide section 122…Fixed mirror 130...Spectrometer 132…Entrance window 133...Collimator mirror 134...Echelle diffraction grating 135...Prism 136…Schmidt mirror 137...Telemeter mirror 138...Photodetector 139…Toroidal mirror 140…Plane mirror 141...Slit plate 200...Control / processing section 201...Spectrum generation unit 202...Spectral storage unit 203...Analysis control section 204…Dirt detection section 205...Display control unit 204…Improvement rate identification section 207…Improvement rate storage unit 211...Operation unit 212...Display section

Claims

1. an analysis unit having a light-emitting unit that excites components in the sample liquid to emit light by atomizing the sample liquid and introducing it into a plasma flame, a spectroscope that wavelength-disperses the emitted light from the plasma flame, a photodetector that detects the wavelength-dispersed emitted light, and a plurality of optical elements arranged on an optical path from the plasma flame to the photodetector; a spectrum generating unit that generates an emission spectrum based on a detection signal from the photodetector; a contamination determination unit that compares a determination spectrum, which is a current emission spectrum obtained by measuring a specified sample in the analysis unit, with a control spectrum, which is an emission spectrum obtained by measuring a sample having the same composition as the specified sample in the past in the analysis unit, and determines whether or not contamination has occurred in any of the plurality of optical elements based on the degree of decrease in intensity of the determination spectrum from the intensity of the control spectrum; a notification unit that notifies a user when it is determined that the stain has occurred; having The dirt determination unit determines that dirt has occurred in any of the plurality of optical elements when the degree of decrease is greater on the short wavelength side than on the long wavelength side within a predetermined wavelength range. ICP optical emission spectrometer.

2. The predetermined wavelength range includes at least a portion of the range from 130 nm to 400 nm. The ICP optical emission spectrometer according to claim 1 .

3. The dirt determination unit determines a short wavelength side intensity ratio, which is the ratio of the intensity of the determination spectrum to the intensity of the control spectrum on the shorter wavelength side than a reference wavelength defined in the wavelength range, and a long wavelength side intensity ratio, which is the ratio of the intensity of the determination spectrum to the intensity of the control spectrum on the longer wavelength side that is equal to or greater than the reference wavelength, and determines that the dirt has occurred when the short wavelength side intensity ratio is smaller than the long wavelength side intensity ratio and the magnitude of the difference between the two is equal to or greater than a predetermined threshold value. The ICP optical emission spectrometer according to claim 1 .

4. When the dirt determination unit determines that the dirt has occurred, the notification unit further notifies a user of a message urging the user to perform predetermined maintenance on those of the plurality of optical elements that can be maintained by the user. The ICP optical emission spectrometer according to claim 1 .

5. a maintenance completion input receiving unit that receives an input from a user indicating that the maintenance has been completed; an analysis control unit that controls the analysis unit to perform remeasurement of the predetermined sample when the maintenance completion input reception unit receives the input; Further comprising: After performing said remeasurement, the dirt determination unit determines whether or not dirt has accumulated in an optical element that cannot be maintained by a user among the plurality of optical elements by comparing a re-determination spectrum, which is an emission spectrum acquired by the re-measurement, with the control spectrum or the determination spectrum, or both; When it is determined that dirt has accumulated on the optical element that cannot be maintained by the user, the notification unit notifies the user that maintenance by the manufacturer is required. The ICP optical emission spectrometer according to claim 4.

Images