JP7845017B2 - Plasma-based elemental analysis device - Google Patents

Description

This invention relates to elemental analysis devices using plasma, such as inductively coupled plasma mass spectrometers (ICP-MS) and inductively coupled plasma atomic emission spectrometers (ICP-AES).

ICP-MS is a method for qualitative and quantitative analysis of individual elements in a sample. It involves introducing a sample into an argon plasma generated within a plasma torch containing an induction coil through which high-frequency current flows. The generated ions are then focused by an ion focusing unit such as an ion lens, followed by mass separation using a mass separator such as a quadrupole mass filter, and finally detected by a detector.

For accurate analysis using ICP-MS, it is necessary that the instrument is free from contamination by samples introduced in previous analyses. To ensure such contamination-free analysis of a sample, the ICP-MS described in Patent Document 1 performs an analysis using pure water after the instrument is started and before analyzing the sample. If the analysis with pure water does not detect any elements exceeding predetermined levels for any of the pre-set analyte elements, the sample analysis is performed. On the other hand, if the analysis with pure water detects one or more analyte elements exceeding predetermined levels, the instrument notifies the analyst of contamination through a text display or indicator light. Upon receiving this notification, the analyst stops the instrument and performs maintenance such as cleaning or replacing parts.

Japanese Patent Application Publication No. 10-106483

In the ICP-MS described in Patent Document 1, analysis of pure water is performed before the start of sample analysis, which requires time before the sample analysis can begin. Furthermore, if contamination is detected as a result of the pure water analysis, the device must be stopped for maintenance, and only after restarting the device can the analysis of the sample to be measured begin. This further increases the time required before the sample analysis can begin.

Up to this point, we have explained using ICP-MS with inductively coupled plasma as the ion source as an example. However, similar problems arise in ICP-AES with inductively coupled plasma as the light source, and even in elemental analyzers that perform elemental analysis of liquid and powder samples using plasmas other than inductively coupled plasma as the ion source or light source.

The problem that this invention aims to solve is to provide a plasma-based elemental analyzer that can shorten the time from device startup to the start of analysis.

To solve the above problems, the plasma-based elemental analysis apparatus according to the present invention was developed.
A plasma generation unit that generates plasma,
A sample/rinse liquid introduction unit selectively introduces either a sample or a rinse liquid into the plasma generated by the plasma generation unit,
An elemental analysis unit that performs elemental analysis by detecting ions or light generated when elements contained in the sample or rinse solution are ionized or atomized by the plasma,
An analysis execution control unit controls the sample/rinse liquid introduction unit and the elemental analysis unit, so that after performing elemental analysis of the sample by the elemental analysis unit, before turning off the plasma, the rinse liquid is introduced into the plasma and then the elemental analysis of the rinse liquid is performed by the elemental analysis unit.
The system includes an elemental analysis result display unit that displays the results of the elemental analysis performed on the rinse solution after the elemental analysis of the rinse solution has been performed and before the plasma is lit for the elemental analysis of the next sample .

In the elemental analyzer according to the present invention, after the analysis of the sample is completed, the analysis execution control unit, before turning off the plasma (without stopping the plasma), introduces a rinse solution (e.g., pure water) into the plasma from the sample/rinse solution introduction unit, and then executes control to perform elemental analysis of the rinse solution in the elemental analysis unit. After the elemental analysis of the rinse solution is performed, the plasma is turned off (stopped). If an amount of element exceeding a predetermined value is detected by the elemental analysis of the rinse solution, the result is displayed on the elemental analysis result display unit, and the analyst then performs maintenance such as cleaning the device or replacing parts. On the other hand, if an amount of element exceeding a predetermined value is not detected by the elemental analysis of the rinse solution, the operation can be terminated as is. In either case (by performing maintenance before the next device startup in the former case), it is not necessary to perform analysis of the rinse solution (pure water) when the device is started up again, and the analysis of the sample can be performed immediately, thus shortening the time until the start of sample analysis.

A schematic diagram showing an ICP-MS, which is a first embodiment of the elemental analyzer according to the present invention. A flowchart illustrating the operation of the ICP-MS in the first embodiment. A diagram showing an example of an image displayed on the display in the ICP-MS of the first embodiment, in which the detection intensity of ions in the sample is below the threshold. This figure shows another example of an image displayed on the display in the ICP-MS of the first embodiment, in which the detection intensity of ions in the sample is above a threshold. A schematic diagram showing an ICP-AES, which is a second embodiment of the elemental analyzer according to the present invention.

An embodiment of the plasma-based elemental analysis apparatus according to the present invention will be explained using Figures 1 to 4.

(1) Configuration of the ICP-MS, an elemental analyzer using plasma according to the first embodiment Figure 1 shows the configuration of the ICP-MS10, an elemental analyzer using plasma according to the first embodiment. The ICP-MS10 comprises an ICP ion source 11, an autosampler 12, and a mass spectrometer (corresponding to the elemental analysis unit described above) 15. The ICP ion source 11 is housed in an ionization chamber 100 at approximately atmospheric pressure, and the mass spectrometer 15 is housed in a vacuum chamber 103 that is evacuated by a rotary pump and a turbomolecular pump (these pumps are not shown). A first intermediate vacuum chamber 101 and a second intermediate vacuum chamber 102 are provided between the ionization chamber 100 and the vacuum chamber 103.

The ICP ion source 11 includes a nebulizer 111 that atomizes the liquid sample supplied from the autosampler 12 with a carrier gas 91, a spray chamber 112 that separates and passes smaller particles of the liquid sample mist generated by the nebulizer 111, and a plasma torch (plasma generation unit) 113. The plasma torch 113 has a sample tube through which the liquid sample mist and carrier gas that have passed through the spray chamber 112 flow, an auxiliary gas tube formed on the outer circumference of the sample tube through which an auxiliary gas passes, and a plasma tube formed on the outer circumference of the auxiliary gas tube through which plasma gas passes (these tubes are not shown). A coil 1131 is wound around the outside of the plasma tube.

The autosampler 12 has a liquid sample storage section 121 for storing the liquid sample to be analyzed and a rinse solution storage section 122 for storing pure water, which is the rinse solution, and corresponds to the sample/rinse solution introduction section. Although only one liquid sample storage section 121 is shown in Figure 1, multiple liquid sample storage sections 121 may be provided to sequentially analyze multiple types of samples. These liquid sample storage sections 121 and rinse solution storage sections 122 are connected to the nebulizer 111 by a liquid introduction tube 123. The liquid introduction tube 123 is provided with an arm 124 that can move between the liquid sample storage section 121 and the rinse solution storage section 122, and by moving this arm 124, only one of the liquid sample storage section 121 or the rinse solution storage section 122 can be selectively connected to the nebulizer 111. Alternatively, instead of using the arm 124, the liquid introduction tube 123 may be branched and connected to the liquid sample storage section 121 and the rinse liquid storage section 122, respectively, and a switching valve may be provided to switch the flow path, thereby selectively connecting only one of the liquid sample storage section 121 or the rinse liquid storage section 122 to the nebulizer 111.

The mass spectrometer 15 comprises a quadrupole mass filter 151 including a pre-rod electrode and a main rod electrode, and an ion detector 152.

An ion lens 14 for focusing ions is located in the second intermediate chamber 102.

The ICP-MS10 further comprises an analysis execution control unit 17, a data analysis unit 18, a data storage unit 181, and an elemental analysis result display unit 19.

The analysis execution control unit 17 controls the operation of the ICP ion source 11, autosampler 12, ion lens 14, and mass spectrometer 15. For the autosampler 12, the analysis execution control unit 17 controls the movement of the arm 124 to connect the liquid sample reservoir 121 and the nebulizer 111, thereby performing analysis of the liquid sample. Then, without stopping the plasma torch 113, the arm 124 is moved to connect the rinse solution reservoir 122 and the nebulizer 111, thereby performing analysis of the rinse solution.

The mass spectrometer 15 is controlled to perform either qualitative or quantitative analysis depending on the purpose of the analysis. If the purpose is to identify the types of elements contained in the sample, the quadrupole mass filter 151 is controlled to switch the m/z of the ions reaching the ion detector 152 within a predetermined range (qualitative analysis). On the other hand, if the content of a specific element needs to be precisely determined, the quadrupole mass filter 151 is controlled to fix the m/z to the value of that element, detection is performed by the ion detector 152 over a longer period than in qualitative analysis, and quantification is performed by applying the detection results to a pre-prepared calibration curve (quantitative analysis). Alternatively, the types of elements contained in the sample may be identified first through qualitative analysis, and then quantitative analysis may be performed on the identified elements. Or, if a rough determination of the element content is sufficient, quantification may be performed based on the detection intensity for each m/z obtained during the qualitative analysis (semi-quantitative analysis).

The data analysis unit 18 receives a detection signal from the ion detector 152 and determines the detection intensity for each m/z based on that detection signal. In the case of qualitative analysis, the elements contained in the sample are identified based on the detection intensity data. The obtained detection intensity data and the results of element identification are stored in the data storage unit 181. In the elemental analysis of the rinse solution described later, a qualitative analysis is performed, and the detection intensity for each m/z obtained during that qualitative analysis is stored in the data storage unit 181.

The elemental analysis result display unit 19 comprises an elemental analysis result display control unit 191 and a display 192. The elemental analysis result display control unit 191 controls the display 192 to show the quantitative results of the elements contained in the sample obtained by quantitative analysis, based on the data obtained by the data analysis unit 18. It also controls the display to highlight the element names and their quantitative values for elements whose detection intensity exceeds a predetermined value. Furthermore, the elemental analysis result display unit 19 controls the display to highlight the element names and their semi-quantitative values for elements whose detection intensity exceeds a predetermined value, obtained from semi-quantitative analysis of the rinse solution (pure water) sample.

The analysis execution control unit 17, the data analysis unit 18, and the elemental analysis result display control unit 191 are implemented using hardware such as a CPU and software.

In addition, the ICP-MS10 has input devices such as a keyboard, mouse, and touch panel for the analyst to input instructions for starting and ending the analysis (not shown in the diagram).

(2) Operation of the ICP-MS of the first embodiment The operation of the ICP-MS 10 of the first embodiment will be explained using the flowchart in Figure 2.

First, the analyst opens the method file containing the measurement conditions by performing a predetermined operation (Step 1). However, at this point, only the hardware and software constituting the analysis execution control unit 17, data analysis unit 18, and elemental analysis result display unit 19 are activated; the plasma torch 113, etc., are not activated.

The elemental analysis result display control unit 191 displays the results of the elemental analysis of the rinse solution (pure water) performed at the end of the previous analysis, along with the method file, stored in the data storage unit 181, on the display 192 (Step 2. For details regarding the elemental analysis of the rinse solution and its display, see Steps 7-9 below). The analyst confirms the analysis results of the rinse solution displayed on the display 192.

As a result, if the elemental names or semi-quantitative values (or detection intensities) indicating contamination of the instrument are not highlighted (details below), or if they are displayed but maintenance such as cleaning or parts replacement has been performed on the instrument since the last analysis, then it is acceptable to proceed with the sample analysis. In these cases, the analyst will perform the prescribed operation to start the sample analysis, thereby igniting the plasma (YES in Step 3 → Step 5). On the other hand, if the above indications are displayed and maintenance has not been performed since the last analysis, the analyst will perform the maintenance without igniting the plasma (NO in Step 3 → Step 4). After the maintenance is complete, the analyst will perform the prescribed operation, proceeding to Step 5, and the plasma will be ignited.

After the plasma is lit, the analysis execution control unit 17 moves the arm 124 of the autosampler 12 so that the liquid sample storage unit 121 and the nebulizer 111 are in communication. This allows for the analysis of the sample contained in the liquid stored in the liquid sample storage unit 121 to be performed as follows (step 6).

The liquid containing the sample in the liquid sample storage unit 121 is atomized and introduced into the plasma torch 113 via the nebulizer 111 and spray chamber 112. The sample is ionized by the plasma generated in the plasma torch 113. The ionized sample passes through the first intermediate vacuum chamber 101 and the second intermediate vacuum chamber 102 and is introduced into the mass spectrometer 15 in the vacuum chamber 103. In the mass spectrometer 15, by varying the voltage applied to the quadrupole mass filter 151 over time, ions with different m/z values at each time interval are detected by the ion detector 152. The data analysis unit 18 identifies the elements contained in the sample based on the detection timing (m/z) and detection intensity of these ions. The detection intensity for each m/z and the identified elements are stored in the data storage unit 181. In this step, or instead of the above operation, a quantitative analysis is performed on the sample to be analyzed, detecting ions with the m/z fixed to a specific value.

After performing the analysis of one sample, if there are other samples to be analyzed (No in step 7), the process returns to step 6 to perform the analysis of the other samples. On the other hand, if there are no other samples to be analyzed (Yes in step 7), the plasma remains lit, and the analysis of the rinse solution is performed (step 8). For the analysis of the rinse solution, the analysis execution control unit 17 first moves the arm 124 of the autosampler 12 so that the rinse solution reservoir 122 and the nebulizer 111 are in communication. This introduces a mist of the rinse solution (pure water) stored in the rinse solution reservoir 122 into the plasma torch 113. The rinse solution serves to clean the inside of the plasma torch 113 and the flow path leading to it, and also to detect the presence or absence of contamination by the sample. That is, if the inside of the plasma torch 113 and the flow path leading to it are not contaminated with the sample, the ion detector 152 will not detect ions originating from the sample. Conversely, if contamination occurs, ions originating from the sample will be detected by the ion detector 152 through the same process as when analyzing the sample.

The data analysis unit 18 identifies the detected elements and their semi-quantitative values based on the detection intensity for each m/z obtained from the analysis of the rinse solution, and analyzes whether the semi-quantitative value (or detection intensity) for each identified element exceeds a predetermined threshold. The elements to be detected here may be limited to elements that can be contained in the sample being measured, or other elements may be included. If the elements to be detected are limited to elements that can be contained in the sample being measured, the elements to be limited and the thresholds corresponding to those elements may be stored in a method file in advance, and the data analysis unit 18 may refer to them. Alternatively, the software may determine the threshold corresponding to the element based on the concentration range set in the calibration curve used for the quantification of the elements to be detected, which is registered in the method file. The elemental analysis result display control unit 191 acquires the analysis result data from the data analysis unit 18, displays the identified elements and their semi-quantitative values (same as above), and further controls the display 192 to highlight the elements whose semi-quantitative values (same as above) exceed the threshold and the semi-quantitative values (same as above) (step 9). The analyst will check the analysis results of the rinse solution displayed on display 192. If a highlighting indicating contamination of the device is shown, the device will be maintained immediately or before the next analysis begins.

After confirming the display on display 192, the analyst performs a predetermined operation to turn off the plasma (step 10), thereby completing the series of operations.

Figures 3A and 3B show examples of elemental analysis results for the rinse solution displayed on the display 192 in steps 2 and 9. Both Figures 3A and 3B display a table on the display 192 showing the identified elements and semi-quantitative values determined based on the detection intensity of each element. In the example in Figure 3A, none of the multiple elements to be analyzed were detected, so they are not highlighted. On the other hand, in the example in Figure 3B, two of the multiple elements to be analyzed (Fe and Ni) have semi-quantitative values above the threshold, which are thought to be due to contamination by the sample. Therefore, these two elements are highlighted by displaying their element names and semi-quantitative values in bolder letters and using a different background color than the other elements, allowing the analyst to notice the presence of contamination. Note that the highlighting method is not limited to this example; for example, element names and semi-quantitative values could be displayed in a different color than other elements, or symbols such as arrows or warning text could be displayed. Alternatively, detection intensity could be displayed instead of semi-quantitative values.

In conventional ICP-MS systems, the plasma is lit and pure water is analyzed during startup. If elements indicating contamination of the system are detected, the plasma torch is turned off for maintenance. Afterward, the plasma is lit again before starting the sample analysis. This required analysis of pure water before sample analysis, and if the system was contaminated, the plasma torch had to be repeatedly turned on and off, resulting in a significant delay before sample analysis could begin. In contrast, with the ICP-MS 10 of this embodiment, there is no need to analyze the rinse solution (pure water) during startup. Once the plasma is lit, sample analysis can be performed without turning it off, thus shortening the time from system startup to the start of analysis.

(3) Configuration of the ICP-AES, an elemental analyzer using plasma according to the second embodiment Figure 4 shows the configuration of the ICP-AES 20, an elemental analyzer using plasma according to the second embodiment. The ICP-AES 20 includes an ICP ion source 21, an autosampler 22, a focusing lens 23, a slit 24, a diffraction grating 25, and a multi-channel detector 26.

The ICP ion source 21 has the same configuration as the ICP ion source 11 in the ICP-MS 10 of the first embodiment. The autosampler 22 has the same configuration as the autosampler 12 in the ICP-MS 10 of the first embodiment, and includes a liquid sample storage section 221, a rinse liquid storage section 222, a liquid introduction tube 223, and an arm 224. By moving the arm 224, either the liquid sample or the rinse liquid is introduced into the nebulizer 211 of the ICP ion source 21. In the ICP ion source 21, the introduced liquid sample or rinse liquid is atomized by the nebulizer 211, introduced into the plasma torch 213 via the spray chamber 212, and then excited by the plasma flame. This causes light with a specific wavelength corresponding to the elements contained in the liquid sample or rinse liquid to be emitted.

The focusing lens 23 is a lens that focuses the light emitted by the plasma torch 213. The slit 24 allows a portion of the light focused by the focusing lens 23 to pass through. The diffraction grating 25 disperses the light that has passed through the slit 24 by wavelength. The multi-channel detector 26 detects the intensity of the light dispersed by the diffraction grating 25 at each wavelength. The intensity of the light at each wavelength detected here corresponds to the amount of the element corresponding to each wavelength contained in the liquid sample or rinsing solution. The diffraction grating 25 and the multi-channel detector 26 having the above functions correspond to the elemental analysis unit in this invention.

The ICP-AES20 further comprises an analysis execution control unit 27, a data analysis unit 28, a data storage unit 281, and an elemental analysis result display unit 29. The elemental analysis result display unit 29 includes an elemental analysis result display control unit 291 and a display 292.

The analysis execution control unit 27 controls the plasma torch 213 and the autosampler 22. Here, the analysis execution control unit 27 controls the autosampler 22 by moving the arm 224 to connect the liquid sample storage unit 221 and the nebulizer 211 to perform analysis of the liquid sample. Then, without stopping the plasma torch 213, it moves the arm 224 to connect the rinse solution storage unit 222 and the nebulizer 211 to perform analysis of the rinse solution.

The data analysis unit 28 receives detection signals from the multi-channel detector 26 corresponding to the light intensity for each wavelength detected by the detector, and identifies and quantifies the elements contained in the sample based on these detection signals. The results of element identification and quantification are stored in the data storage unit 281.

The elemental analysis result display control unit 291 controls the display 292 to display the results of the identification and quantification of elements contained in the sample, obtained by the data analysis unit 28. The display 192 displays the results based on the control of the elemental analysis result display control unit 291.

In addition, the ICP-AES20 has input devices such as a keyboard, mouse, and touch panel for the analyst to input instructions for starting and ending the analysis (not shown in the diagram).

(4) Operation of ICP-AES in the second embodiment The operation flow of analysis using ICP-AES20 is basically the same as that of ICP-MS. Therefore, its operation will be explained with reference to Figure 2.

First, the analyst turns on the ICP-AES20 by performing a predetermined operation. At this point, only the hardware and software constituting the analysis execution control unit 27, data analysis unit 28, and elemental analysis result display unit 29 are activated; the plasma torch 213 and other components are not activated.

The elemental analysis result display control unit 291 displays the results of the elemental analysis of the rinse solution (pure water) performed at the end of the previous analysis, which are stored in the data storage unit 281, on the display 292 (Step 2). The analyst confirms the analysis results of the rinse solution displayed on the display 292. If no indication of contamination of the device is displayed, or if maintenance has been performed since the end of the previous analysis even if such indications are displayed, the plasma is turned on by performing a predetermined operation to start the sample analysis (YES in Step 3 → Step 5). On the other hand, if the above indications are displayed and maintenance has not been performed since the end of the previous analysis, maintenance is performed without turning on the plasma, and the plasma is turned on after the maintenance is completed (Step 5).

After the plasma is lit, the analysis execution control unit 27 moves the arm 224 of the autosampler 22 so that the liquid sample storage unit 221 and the nebulizer 211 are in communication. This performs the analysis of the liquid sample (step 6). Specifically, the liquid containing the sample in the liquid sample storage unit 221 is atomized by the nebulizer 211, introduced into the plasma torch 213 via the spray chamber 212, and then excited by the plasma flame, emitting light with a specific wavelength corresponding to the elements contained in the liquid sample. The emitted light passes through the focusing lens 23 and slit 24, is wavelength-dispersed by the diffraction grating 25, and the intensity for each wavelength is detected by the multi-channel detector 26. The detection signal from the multi-channel detector 26 is transmitted to the data analysis unit 28, where the elements contained in the sample are identified and quantified.

After performing the analysis of the liquid samples described above on all liquid samples to be analyzed (YES in step 7), the analysis of the rinse solution is performed while the plasma torch 213 remains lit (step 8). Specifically, the analysis execution control unit 27 moves the arm 224 of the autosampler 22 so that the rinse solution reservoir 222 and the nebulizer 211 are in communication, thereby introducing a mist of rinse solution (pure water) into the plasma torch 213. The light emitted by the plasma torch 211 is then wavelength-dispersed by the diffraction grating 25, and the intensity of each wavelength is detected by the multi-channel detector 26.

The data analysis unit 28 performs element identification and quantification based on the detection signal from the multi-channel detector 26. If the plasma torch 213 and the flow path leading to it are not contaminated with the sample during liquid sample analysis, no ions originating from the sample will be detected during rinse solution analysis. Conversely, if the aforementioned areas are contaminated with the sample during liquid sample analysis, light originating from the sample will be detected during rinse solution analysis. The elemental analysis result display control unit 291 acquires the analysis result data from the data analysis unit 28 and displays the analysis result on the display 292 (step 9). The analysis result data displayed here, as in the first embodiment, represents the identified elements and semi-quantitative values (or detection intensities), and elements with semi-quantitative values (or detection intensities) above a threshold can be highlighted.

The analyst checks the analysis results of the rinse solution displayed on display 292. If peaks in the spectrum indicating contamination or characters indicating the presence of contamination are displayed, the analyst performs maintenance on the device immediately or before starting the next analysis. After checking the display on display 292, the analyst performs the prescribed operation to turn off the plasma (step 10), thereby completing the series of operations.

According to the ICP-AES20 of this embodiment, similar to the ICP-MS10, it is not necessary to analyze the rinsing solution (pure water) when starting the device. Once the plasma torch is lit, the sample can be analyzed without turning it off, thus shortening the time from device startup to the start of analysis. Furthermore, the analysis of the rinsing solution (pure water) after sample analysis can also be performed without turning off the plasma torch, further reducing working time.

(5) Modifications The present invention is not limited to the embodiments described above, and various modifications are possible.

In the above embodiment, pure water was used as the rinsing solution, but other rinsing solutions may be used. For example, a solvent used to dissolve solid samples when preparing liquid samples may be used as the rinsing solution.

The configurations of the ICP-MS and ICP-AES shown in the above embodiments are merely examples, and various configurations commonly used in ICP-MS and ICP-AES can be applied to the present invention. For example, in the ICP-MS, a collision cell/reaction cell may be provided in addition to the configuration of the above embodiments. In the ICP-AES, the optical system between the plasma torch 211 and the spectroscopic crystal 25 is not limited to that shown in the above embodiments, and various types can be used. Furthermore, in the ICP-AES, instead of detecting light of different wavelengths with a multi-channel detector 26, a sequential configuration may be adopted in which the wavelength detected by the detector is changed by rotating the diffraction grating. The plasma generation unit is not limited to a plasma torch, and other means for generating plasma may be used.

[Pattern]
It will be obvious to those skilled in the art that the exemplary embodiments described above are specific examples of the following embodiments.

(Section 1)
The elemental analysis apparatus using plasma as described in paragraph 1 is
A plasma generation unit that generates plasma,
A sample/rinse liquid introduction unit selectively introduces either a sample or a rinse liquid into the plasma generated by the plasma generation unit,
An elemental analysis unit that performs elemental analysis by detecting ions or light generated when elements contained in the sample or rinse solution are ionized or atomized by the plasma,
An analysis execution control unit controls the sample/rinse liquid introduction unit and the elemental analysis unit, so that after performing elemental analysis of the sample by the elemental analysis unit, before turning off the plasma, the rinse liquid is introduced into the plasma and then the elemental analysis of the rinse liquid is performed by the elemental analysis unit.
The system includes an elemental analysis result display unit that displays the results of elemental analysis performed on the rinse solution.

In the elemental analyzer described in paragraph 1, the analysis execution control unit, after the analysis of the sample is completed, and before turning off the lights (without stopping the plasma), introduces a rinse solution (e.g., pure water) into the plasma through the sample/rinse solution introduction unit, and then executes control to perform elemental analysis of the rinse solution in the elemental analysis unit. After the elemental analysis of the rinse solution is performed, the plasma is turned off (stopped). If an amount of element exceeding a predetermined value is detected by the elemental analysis of the rinse solution, the result is displayed on the elemental analysis result display unit, and the analyst then performs maintenance such as cleaning the device or replacing parts. On the other hand, if an amount of element exceeding a predetermined value is not detected by the elemental analysis of the rinse solution, the operation can be terminated as is. In either case (by performing maintenance before the next device startup in the former case), it is not necessary to perform analysis of the rinse solution (pure water) when the device is started up again, and the analysis of the sample can be performed immediately, thus shortening the time until the start of sample analysis.

The timing at which the elemental analysis result display unit displays the elemental analysis results of the rinse solution may be after the elemental analysis of the rinse solution has been performed but before the predetermined termination operation (e.g., turning off the plasma), or it may be after the termination operation. Alternatively, the elemental analysis results of the rinse solution may be displayed after the predetermined start operation (e.g., opening the measurement method) for the next sample analysis has been performed.

(Section 2)
The elemental analysis apparatus using plasma according to paragraph 2 is an elemental analysis apparatus using plasma according to paragraph 1, wherein the elemental analysis result display unit displays the elements identified as being contained in the rinse liquid as a result of elemental analysis performed on the rinse liquid, and the quantitative value (including the semi-quantitative value) or detection intensity of the elements, and displays elements whose quantitative value or detection intensity is above a predetermined threshold, distinguishing them from other elements.

According to the elemental analyzer described in paragraph 2, the elemental analysis results of the rinse solution will clearly indicate elements with a quantitative value or detection intensity above a predetermined threshold on the spectrum that are highly likely to be due to contamination of the analyzer, thereby allowing the analyst to easily recognize contamination of the analyzer. Here, the quantitative value or detection intensity can be obtained by mass spectrometry if the elemental analyzer is an ICP-MS, or by wavelength spectrometry if the elemental analyzer is an ICP-AES.

As stipulated in Section 4 below, when the results of elemental analysis of the rinse solution are displayed twice, the possibility of the user overlooking an element can be further reduced by distinguishing it from other elements in both displays, where the quantitative value or detection intensity is above a predetermined threshold.

(Section 3)
In the elemental analysis apparatus using plasma according to paragraph 3, the threshold is set for an element selected based on the information of the element to be measured, which is set when a predetermined start operation is performed to start the elemental analysis of the sample in the elemental analysis apparatus using plasma according to paragraph 2.

According to the elemental analyzer described in paragraph 3, the threshold is set for the element selected based on the information of the element to be measured (which may be contained in the sample) that is set when the start operation is performed (for example, registered in the method file). Therefore, it is possible to accurately detect whether the element to be measured is mixed into the rinse solution, i.e., whether the device is contaminated by the sample to be measured.

(Section 4)
The elemental analyzer using plasma described in paragraph 4 is an elemental analyzer using plasma described in any one of paragraphs 1 to 3,
The elemental analysis result display unit is,
After elemental analysis of the rinse solution has been performed and before the predetermined start operation for starting the elemental analysis of the next sample is carried out, the results of the elemental analysis of the rinse solution are displayed.
From the time the start operation for the elemental analysis of the next sample is performed until the elemental analysis of the next sample begins, the results of the elemental analysis of the rinse solution performed after the completion of the elemental analysis of the previous sample will be displayed.

According to the elemental analyzer described in paragraph 4, the results of the elemental analysis of the rinse solution are displayed twice: once after the elemental analysis of the rinse solution is performed and before the start of the elemental analysis of the next sample, and again after the start of the elemental analysis of the next sample. Therefore, the possibility of the user overlooking the detection of an element exceeding a predetermined value in the rinse solution is reduced.

10... ICP-MS
100...Ionization chamber 101...First intermediate vacuum chamber 102...Second intermediate vacuum chamber 103...Vacuum chamber 11...ICP ion source 111, 211...Nebulizer 112, 212...Spray chamber 113, 213...Plasma torch 12, 22...Autosampler 121, 221...Liquid sample storage section 122, 222...Rinse liquid storage section 123, 223...Liquid introduction tube 124, 224...Arm 14...Ion lens 151...Quadrupole mass filter 152...Ion detector 17, 27...Analysis execution control section 18, 28...Data analysis section 181, 281...Data storage section 19, 29...Elemental analysis result display section 191, 291...Elemental analysis result display control section 192, 292...Display 20...ICP-AES
23... Focusing lens 24... Slit 25... Diffraction grating 26... Multi-channel detector

Claims (4)

A plasma generation unit that generates plasma,
A sample/rinse liquid introduction unit selectively introduces either a sample or a rinse liquid into the plasma generated by the plasma generation unit,
An elemental analysis unit that performs elemental analysis by detecting ions or light generated when elements contained in the sample or rinse solution are ionized or atomized by the plasma,
An analysis execution control unit controls the sample/rinse liquid introduction unit and the elemental analysis unit, so that after performing elemental analysis of the sample by the elemental analysis unit, before turning off the plasma, the rinse liquid is introduced into the plasma and then the elemental analysis of the rinse liquid is performed by the elemental analysis unit.
A plasma-based elemental analyzer comprising: an elemental analysis result display unit that displays the results of the elemental analysis performed on the rinse solution after the elemental analysis of the rinse solution has been performed and before the plasma is lit for the elemental analysis of the next sample. The elemental analysis result display unit displays the elements identified as being present in the rinse solution as a result of elemental analysis performed on the rinse solution, as well as the quantitative value or detection intensity of those elements, and distinguishes and displays elements whose quantitative value or detection intensity is above a predetermined threshold from other elements, as described in claim 1. The elemental analyzer using plasma according to claim 2, wherein the threshold is set for an element selected based on information about the element to be measured, which is set when a predetermined start operation is performed to initiate elemental analysis of the sample. A plasma generation unit that generates plasma,
A sample/rinse liquid introduction unit selectively introduces either a sample or a rinse liquid into the plasma generated by the plasma generation unit,
An elemental analysis unit that performs elemental analysis by detecting ions or light generated when elements contained in the sample or rinse solution are ionized or atomized by the plasma,
An analysis execution control unit controls the sample/rinse liquid introduction unit and the elemental analysis unit, so that after performing elemental analysis of the sample by the elemental analysis unit, before turning off the plasma, the rinse liquid is introduced into the plasma and then the elemental analysis of the rinse liquid is performed by the elemental analysis unit.
An elemental analysis result display unit that displays the results of elemental analysis performed on the rinse solution.
Equipped with,
The elemental analysis result display unit,
After elemental analysis of the rinse solution has been performed and before the predetermined start operation for starting the elemental analysis of the next sample is carried out, the results of the elemental analysis of the rinse solution are displayed.
From the time the aforementioned start operation for the elemental analysis of the next sample is performed until the elemental analysis of the next sample begins, the results of the elemental analysis of the rinse solution performed after the completion of the elemental analysis of the previous sample are displayed .
A plasma -based elemental analysis device.