CN117848976A

CN117848976A - Sample analysis system

Info

Publication number: CN117848976A
Application number: CN202311279376.6A
Authority: CN
Inventors: 马库斯·格罗斯曼; 尤里·卡林依特成科; 沃尔弗拉姆·魏斯海特; 菲利普·弗雷德里克·舒尔茨
Original assignee: Analytik Jena Co Ltd Kg
Current assignee: Analytik Jena Co Ltd Kg
Priority date: 2022-10-07
Filing date: 2023-09-28
Publication date: 2024-04-09

Abstract

The present invention relates to a sample analysis system. The invention relates to a method for analyzing a sample (2) by means of a system (1), wherein the sample (2) is a solid sample and comprises a first chemical element and a second chemical element, wherein the system (1) comprises a plasma spectrometer (21) and an analysis device (22), wherein the method comprises at least the following steps: determining the concentration of the first chemical element by an analysis device (22), determining the sensitivity of the plasma spectrometer (21) to the first chemical element and to the second chemical element, measuring the signal intensity of the first chemical element by the plasma spectrometer (21), measuring the signal intensity of the second chemical element by the plasma spectrometer (21), calculating the concentration of the second chemical element from the determined concentration of the first chemical element, the sensitivity to the first chemical element and to the second chemical element, and the signal intensities of the first chemical element and the second chemical element.

Description

Sample analysis system

Technical Field

The invention relates to a method for analyzing a sample by means of a system, wherein the sample is a solid sample and comprises a first chemical element and a second chemical element, wherein the system comprises a plasma spectrometer and an analysis device, wherein the plasma spectrometer is configured to ionize the sample by means of a plasma, thereby generating ions and/or photons, and to analyze the generated ions and/or photons, wherein the analysis device is configured to determine the concentration of the first chemical element, wherein the sample is provided to the plasma spectrometer in the form of an aerosol. The invention also relates to a system for analyzing a sample, the system comprising a plasma spectrometer and an analysis device.

Background

Plasma spectrometers utilize plasma to ionize a sample and generate ions and/or photons from the sample. Ions are typically analyzed by mass spectrometry, while photons are typically analyzed by optical spectrometry.

In a mass spectrometer, molecules or atoms of a sample are first converted to a gas phase and ionized. For ionization, various methods known in the art are available, such as inductively coupled plasma Ionization (ICP) by plasma ionization of the sample. To date, several different types of inductively coupled plasma mass spectrometers (ICP-MS) are available, such as quadrupole ICP-MS or time-of-flight ICP-MS.

After ionization, the ions reach a mass analyzer through a vacuum interface, where they are separated according to their mass-to-charge ratio m/z. Different types of interfaces and modes of operation are based, for example, on the application of static or dynamic electric and/or magnetic fields, or on different times of flight of different ions. In particular, different types of interfaces include single, multiple or hybrid arrangements of analyzers, such as quadrupoles, triple quadrupoles, time of flight (TOF), ion traps, orbitraps or magnetic sectors. Finally, the separated ions are directed to a detector, such as one of a photo-ion multiplier, an ion electron multiplier, a faraday collector, a belili detector, a microchannel plate, or a channel tube.

Ions generated during ionization of a sample by inductively coupled plasma Ionization (ICP) can be analyzed with an optical spectrometer, such as an inductively coupled plasma optical emission spectrometer (ICP-OES).

Inductively coupled plasma is typically maintained with argon. Recently, an alternative ionization method has been described which uses nitrogen to sustain a plasma, the so-called mica (microwave inductively coupled atmospheric plasma), which can be applied to mass spectrometry as well as optical spectroscopy (see US 9706635 B2). MICAP produces a plasma that is also sustainable for air. As previously described in US 63/375746, a nitrogen-sustained plasma may even be used to draw the sample into the mass spectrometer and towards the plasma.

However, both mass spectrometers and optical spectrometers require calibration with the aid of standard or reference materials containing known concentrations of chemical elements. Although calibration of liquid samples is established, calibration of solid samples remains a problem. Due to small sample inconsistencies during the entry of the sample into the plasma, e.g. due to differences in particle size or density within the sample, the signal intensity obtained at the detector of the plasma spectrometer is not fixed, but fluctuates.

Disclosure of Invention

It is therefore an object of the present invention to provide a method and a system with which a plasma spectrometer can be calibrated in an easy manner.

This object is achieved by a method of analyzing a sample by a system, wherein the sample is a solid sample and comprises a first chemical element and a second chemical element, wherein the system comprises a plasma spectrometer and an analysis device, wherein the plasma spectrometer is configured to ionize the sample by a plasma, thereby generating ions and/or photons, and to analyze the generated ions and/or photons, wherein the analysis device is configured to determine the concentration of the first chemical element, wherein the sample is provided to the plasma spectrometer in the form of an aerosol, wherein the method comprises at least the steps of:

determining the concentration of the first chemical element by the analysis device,

determining the sensitivity of the plasma spectrometer to the first chemical element and the second chemical element,

measuring the signal intensity of the first chemical element by means of the plasma spectrometer,

measuring the signal intensity of the second chemical element by means of the plasma spectrometer,

-calculating the concentration of the second chemical element from the determined concentration of the first chemical element, the sensitivity to the first chemical element and to the second chemical element and the signal intensities of the first chemical element and the second chemical element.

With the present invention, the concentration of the first chemical element determined by the analysis device is used to calibrate the signal intensity of the plasma spectrometer. Although the signal intensity of the solid sample fluctuates, all signal intensities fluctuate in the same order. Thus, the signal intensity is calibrated by assigning the determined concentration to one of the signal intensities, i.e. the first chemical element. The concentration of the second chemical element (and other chemical elements) is then calculated.

Typically, each chemical element is detected by the plasma spectrometer with its corresponding sensitivity, which needs to be taken into account during the calculation of the concentration of the second chemical element. Typically, the respective sensitivities of the first chemical element and the second chemical element are determined during an initial setup of the plasma spectrometer, typically using a reference standard having known concentrations of the first and second chemical elements.

There are different ways to calculate the concentration of the second chemical element: one way is to determine the ratio of the signal intensities of the first and second chemical elements, determine the ratio of the sensitivity to the first and second chemical elements, multiply the determined ratio of the concentration of the first chemical element to the sensitivity and divide the result by the determined ratio of the signal intensities.

Another way is to determine the ratio of the signal intensities of the first and second chemical elements, determine the ratio of the sensitivity to the first chemical element and the sensitivity to the second chemical element, divide the determined concentration of the first chemical element by the signal intensity of the first chemical element, and then multiply the result by the ratio of the signal intensity of the second chemical element and the sensitivity to obtain the concentration of the second chemical element.

There may be other ways to calculate the concentration of the second chemical element, which also fall within the scope of the invention.

Typically, the plasma spectrometer is configured to determine the concentration of (at least) the second element with a much higher accuracy than the analysis device. Therefore, the concentration of the second chemical element is preferably determined by a plasma spectrometer.

There are many methods of producing aerosols from solid samples, which fall within the scope of the invention.

In one embodiment, the sample is a powder or dust or rock sample or a soil sample or a pharmaceutical or food sample.

In another embodiment, the surface of the sample is machined such that the sample is partially in the form of an aerosol. The sample surface may be machined so that dust or powder is generated from its surface, for example by drilling, scraping or grinding. The dust or powder may form an aerosol with the surrounding atmosphere (e.g., air).

Furthermore, the sample may be provided in the form of a solid cylinder. A solid cylinder may be obtained by surface drilling. In order to find metals or other valuable elements in the earth, in particular underground, long cylinders up to 1 km or more are drilled into the earth. The cylindrical sample is brought to the surface and analyzed for chemical elements.

In another embodiment, the sample is formed into an aerosol form by exposure to mechanical processing, light, electricity, and/or sound waves. The sample may be exposed to intense light or laser pulses to generate dust or powder from the sample surface. Similarly, the sample may also be exposed to focused ultrasound, thereby generating dust or powder from the surface of the sample. Also, aerosols may be formed in air and provided to the plasma spectrometer in this form.

The object of the invention is also achieved by a system for analyzing a sample, the system comprising a plasma spectrometer and an analysis device, wherein the sample is a solid sample and comprises a first chemical element and a second chemical element, wherein the plasma spectrometer is configured to ionize the sample by a plasma, thereby generating ions and/or photons, and to analyze the generated ions and/or photons, wherein the analysis device is configured to determine the concentration of the first chemical element, wherein the sample is provided to the plasma spectrometer in the form of an aerosol, wherein the system is configured to perform the method according to any of the preceding claims.

With the present invention, simple calibration of the plasma spectrometer with respect to solid samples is possible, which enables fast and direct sample analysis. In one embodiment, the plasma spectrometer and the analysis device are arranged such that the same region or portion of the sample is analyzed by either device. The concentration of the first chemical element and/or the second chemical element may be different throughout the sample, especially in the case of large samples. Thus, it may be desirable to use both the plasma spectrometer and the analysis device to analyze the same region or portion of the sample.

In another embodiment, the system includes a sample unit configured to move the sample in a direction in which the analysis device and the plasma spectrometer are arranged such that either device continuously analyzes the same region or portion of the sample. In this embodiment, a continuous analysis of the sample can be performed.

Furthermore, the system may comprise a cleaning unit configured to clean and/or dry the sample before providing the sample to the analysis device and/or the plasma spectrometer. The sample may be wet and/or contain dirt or other materials on its surface that need to be removed before the sample can be analyzed by a plasma spectrometer and/or analysis device.

Another embodiment comprises the analysis device being configured to determine the concentration of the first chemical element with a high accuracy, in particular with an accuracy of less than 3% relative standard deviation. In order to ensure accurate calibration of the plasma spectrometer by the analysis device, the analysis device is ideally able to determine the first chemical element with high accuracy.

It is further preferred that the plasma spectrometer is configured to determine the concentration of the second element in a concentration range that is not or only partially available to the analysis device. Typically, the analysis device is not able to determine the concentration of the second element at all, or is able to determine the concentration of the second element only with a relatively low accuracy. By determining the concentration of the second chemical element using a plasma spectrometer, a higher accuracy can be obtained or can be measured.

Preferably, the plasma spectrometer is configured to aspirate a sample in the form of an aerosol, in particular by means of a plasma. The plasma spectrometer can include a plasma torch configured to generate a plasma. The plasma may be configured to draw the sample into the plasma.

In one embodiment, the plasma spectrometer is a microwave inductively coupled atmospheric plasma mass spectrometer, a microwave inductively coupled atmospheric plasma optical emission spectrometer, a radio frequency inductively coupled mass spectrometer, a radio frequency inductively coupled optical spectrometer, a glow discharge mass spectrometer, or a glow discharge optical spectrometer.

In another embodiment, the analysis device is an X-ray fluorescence spectrometer, a laser induced breakdown spectrometer, or an X-ray diffractometer.

Drawings

Hereinafter, the present invention and its preferred embodiments will be described with reference to fig. 1 to 6.

Fig. 1 shows the general scheme of a plasma spectrometer.

Fig. 2 shows one embodiment of a plasma spectrometer.

Fig. 3 shows an embodiment of a system according to the invention.

Fig. 4 shows a table in which the calculation and the result of the method according to the invention are shown.

Fig. 5 shows another embodiment of the system according to the invention.

Fig. 6 shows another embodiment of the system according to the invention.

In the drawings, like elements are provided with like reference numerals.

Detailed Description

Fig. 1 schematically illustrates an exemplary plasma spectrometer 21 that may be used with the present invention. The plasma spectrometer 21 may comprise a sample preparation unit 3 with a sample inlet 4 and a plasma torch 5, an interface 7, a detector 8 and an evaluation unit 9. The sample inlet 4 may be arranged upstream of the plasma torch 5. The components of the plasma spectrometer 21 may also be arranged differently.

The plasma spectrometer 21 may be configured to allow the sample 2 to be introduced into the plasma 6 in a downward-pointing vertical direction and/or to allow ions to be extracted from the plasma 6 in a downward-pointing vertical direction. The downward pointing vertical direction points in the same direction as gravity. The plasma torch 5 may comprise a vertically oriented injector tube configured to introduce the sample 2 into the plasma 6. The plasma torch 5 may be arranged vertically. With such an embodiment, the carrier gas used to introduce the sample 2 into the plasma torch 5 has less effect on sample introduction. It is even possible to omit the carrier gas so that the sample 2 is introduced into the plasma 6 by gravity only. Obviously, other arrangements of the plasma torch 5 are also within the scope of the invention.

The evaluation unit 9 can also be arranged separately from the other components. The plasma spectrometer 21 or some of its components may be housed in a housing (not shown). In case the plasma spectrometer 21 is implemented as a mass spectrometer, the interface 7 may be a mass analyzer and the detector 8 may be an ion electron multiplier, a faraday collector, a belgium detector, a microchannel plate or a channel tube. In case the plasma spectrometer 21 is implemented as an optical spectrometer, the interface 7 may be a wavelength selector and the detector 8 may be a photomultiplier tube or a CCD camera.

Fig. 2 illustrates an exemplary embodiment of a plasma spectrometer 21 as a microwave inductively coupled atmospheric plasma mass spectrometer (mica-MS). The sample 2 may be pumped into the mass spectrometer 21 through the sample inlet 4 by the plasma 6. The plasma 6 is generated by a mica source 27 in combination with a waveguide 28 dedicated to the mica. Upon entering the plasma torch 5, the sample 2 is ionized by the plasma 6, thereby generating ions and/or photons. To detect the generated ions with the detector 8, the ions 31 are directed towards the detector 8 by ion optics 30 and a mass analyser 35.

After the plasma 6, a skimmer cone 33 is provided to skim the ions and focus them into the ion beam 31. A collision/reaction gas 32 may be introduced into the ion beam 31 to remove interfering ions through ion/neutral reactions. The ion beam 31 is then directed through an ion mirror 30 and focused to a mass analyzer 35 where the ions are separated according to their mass to charge ratio m/z. The ions are then detected by the detector 8. The pump 29 may be arranged to create a vacuum condition after the plasma torch 5.

Fig. 3 illustrates an embodiment of a system 1 according to the invention comprising a plasma spectrometer 21 and an analysis device 22. The plasma spectrometer 21 is configured to ionize the sample 2 by the plasma 6, thereby generating ions and/or photons, and analyze the generated ions and/or photons. The analysis device 22 is configured to determine a concentration of the first chemical element. Sample 2 is a solid sample, such as a powder or dust or rock sample or a soil sample or a pharmaceutical or food sample, and is provided to plasma spectrometer 21 in the form of an aerosol. There are many ways to generate aerosols from solid samples, including mechanical, electrical, photonic or acoustic methods. Typically, particles or dust or powder are generated from the sample, which then form an aerosol with surrounding gas (e.g., air).

In order to carry out the method according to the invention, the plasma spectrometer 21 and the analysis device 22 may be connected via a cable (illustrated in dashed lines) such that the concentration of the first chemical element is transmitted from the analysis device 22 to the plasma spectrometer 21, in particular to the evaluation unit 9 of the plasma spectrometer 21. The plasma spectrometer 21 may be a microwave inductively coupled atmospheric plasma mass spectrometer, a microwave inductively coupled atmospheric plasma optical emission spectrometer, a radio frequency inductively coupled mass spectrometer, a radio frequency inductively coupled optical spectrometer, a glow discharge mass spectrometer or a glow discharge optical spectrometer. Analysis device 22 may be an X-ray fluorescence (XRF) spectrometer, a laser induced breakdown spectrometer, or an X-ray diffractometer.

XRF spectrometers are commonly used to determine the concentration of gold or other (noble) chemical elements in soil samples because they are simple to use and can be used in the field (i.e., where the sample is found or drilled, etc.). Samples with sufficiently high gold concentration are then sent to a laboratory where the gold concentration is more accurately determined by a plasma spectrometer. Today, mining companies are interested in gold concentrations as low as 1 ppm. However, XRF spectrometers cannot measure gold concentrations below 10ppm with high accuracy. Clearly, the site lacks accessibility to the gold concentration of the soil sample.

With the present invention, the system 1 provides gold concentrations (or concentrations of other noble metals or chemical elements) at high precision in the field, even as low as very low gold concentrations, for example as low as 1.2ppb. Although XRF may not be used to measure gold concentration at all or only with low accuracy, it is able to measure other chemical elements that may be abundant in sample 2 with high accuracy. For example, an XRF spectrometer may be used to determine the concentration of aluminum or silicon (as the first chemical element) in sample 2. The concentration of aluminum or silicon determined by XRF can be used to calibrate the plasma spectrometer 21. The gold concentration in sample 2 can then be determined with high accuracy. Fig. 4 provides another example.

Fig. 4 shows a table of experimental results of a system according to the present invention. Three reference standards from NIST were used to test the system, each standard containing 12% calcium and varying concentrations of gold. In the first column, reference standards and concentrations of the chemical elements to be analyzed are given, respectively. The second column gives the concentration determined by XRF. For gold concentration, a corresponding error was added. Although XRF has a slightly lower error of about 8% in a reference standard containing 25ppm gold, the error is as high as 60% in a reference standard containing 5ppm gold. XRF did not detect any gold in the last reference standard containing 0.18ppm gold. The third column gives the signal intensities of the respective chemical elements of the respective reference standard obtained by a plasma mass spectrometer (e.g. as shown in fig. 2). The fourth column gives the sensitivity of the plasma spectrometer to calcium and gold. The calculated concentration of the second chemical element, gold, is shown in the last column.

The ratio of the signal intensities of calcium (first chemical element) and gold (second chemical element) of NIST 610 samples was approximately 1,653. The ratio of sensitivity to the first chemical element to the second chemical element is about 0.345.

The concentration of the second chemical element may be obtained by multiplying the determined concentration of the first chemical element by the ratio of the sensitivities and by dividing the result by the determined ratio of the signal intensities. In another way, the concentration of the second chemical element may be obtained by: the determined concentration of the first chemical element is divided by the signal intensity of the first chemical element, and then the result is multiplied by the ratio of the signal intensity and sensitivity of the second chemical element. After calibrating the plasma spectrometer with the concentration of the first chemical element, the gold concentration can be determined with high accuracy, even in a reference standard containing only 0.18ppm gold.

Fig. 5 shows another embodiment of the system 1, wherein the sample 2 is provided as a solid cylinder. A solid cylinder may be obtained by surface drilling. The plasma spectrometer 21 and the analysis device 22 may be arranged such that the same area or portion of the sample 2 is analyzed by either device 21, 22. The surface of the sample may be processed using the drilling unit 23 to form an aerosol (in air) which is provided to the plasma spectrometer 21. The analysis device 22 may be configured to determine the concentration of the first chemical element based on the solid sample or the aerosol. The system 1 may further comprise a sample unit 36, which sample unit 36 is configured to move the sample 2 in a direction such that the plasma spectrometer 21 and the analysis device 22 may continuously analyze the sample 2. Furthermore, the system 1 may comprise a cleaning unit 26, which cleaning unit 26 is configured to clean and/or dry the sample 2 before providing the sample 2 to the analysis device 22 and/or the plasma spectrometer 21.

The plasma spectrometer 21 may further comprise additional components, such as a sample introduction unit 19 and/or a classifier 16 as shown in fig. 6.

The sample introduction unit 10 may be configured to introduce the sample 2 into the sample inlet 4 of the plasma spectrometer 21. The sample introduction unit 10 may include: a transport device 11, such as a moving belt 14, the transport device 11 being configured to transport the sample 2 towards the sample inlet 4; and a connection unit 12, the connection unit 12 being configured to be connectable with the sample inlet 4. The sample introduction unit 10 in fig. 6 further comprises a transport tube 25, through which transport tube 25 particles 13, such as dust or powder, are guided towards the moving belt 14, which moving belt 14 is loaded with particles 13, and the particles 13 are moved towards the sample inlet 4 by means of rollers 24. The dose controller 15 is arranged and configured to control the amount of particles 13 entering the sample inlet 4 through the connection unit 12. The sample inlet 4 or sample introduction unit 10 may be open to the surrounding atmosphere in order to draw in particles together with air to form the sample 2. The sample introduction unit 10 may be directly connected to the sample inlet 4 (not shown).

The plasma spectrometer 21 may further comprise a classifier 16 as shown in fig. 6, configured to separate smaller particles from larger particles in the sample 2 and to direct particles having a mass below a predetermined upper mass limit to the sample inlet 4. Classifier 16 may include: a container 17, the container 17 having an inlet 18 for connection to air or gas and an outlet 19 connectable to the sample inlet 4. Furthermore, the tube 20 may be partially inserted into the container 17 such that the flow of the sample 2 is opposite to the flow of particles having a mass below the predetermined upper mass limit towards the outlet 19. Particles having a mass above the predetermined upper mass limit will settle towards the lower end of the vessel 17. The pumping characteristics of the plasma 6 may be used to pump particles 13 together with air as sample 2 into the plasma spectrometer 1. Preferably, the classifier 16 is arranged between the sample introduction unit 10 and the sample inlet 4.

The location of the analysis device 22 may vary: it may be arranged beside the transport means 11, or beside the connection unit 12, or between the classifier 16 and the sample inlet 4.

Reference numerals

1. System and method for controlling a system

2. Sample of

3. Sample preparation unit

4. Sample inlet

5. Plasma torch

6. Plasma body

7. Interface

8. Detector for detecting a target object

9. Evaluation unit

10. Sample introduction unit

11. Conveying device

12. Connection unit

13. Particles

14. Movable belt

15. Dose controller

16. Classifier

17. Container

18. An inlet

19. An outlet

20. Pipe

21. Plasma spectrometer

22. Analysis device

23. Drilling unit

24. Roller

25. Conveying pipe

26. Cleaning unit

27 MICAP Source

28 MICAP waveguide

29. Pump with a pump body

30. Ion mirror

31. Ion beam

32. Reaction/collision gas

33. Skimmer cone

34. Focused ion beam

35. Mass analyser

36. Sample unit

Claims

1. A method of analyzing a sample (2) by a system (1), wherein the sample (2) is a solid sample and comprises a first chemical element and a second chemical element, wherein the system (1) comprises a plasma spectrometer (21) and an analysis device (22), wherein the plasma spectrometer (21) is configured to ionize the sample (2) by means of a plasma (6) thereby generating ions and/or photons and to analyze the generated ions and/or photons, wherein the analysis device (22) is configured to determine the concentration of the first chemical element, wherein the sample (2) is provided to the plasma spectrometer (21) in the form of an aerosol, wherein the method comprises at least the following steps:

determining the concentration of the first chemical element by means of the analysis device (22),

determining the sensitivity of the plasma spectrometer (21) to the first chemical element and to the second chemical element,

measuring the signal intensity of the first chemical element by means of the plasma spectrometer (21),

measuring the signal intensity of the second chemical element by means of the plasma spectrometer (21),

-calculating the concentration of the second chemical element from the determined concentrations of the first chemical element, the sensitivities to the first chemical element and to the second chemical element, and the signal intensities of the first chemical element and the second chemical element.

2. The method according to claim 1,

wherein the sample (2) is a powder or dust or rock sample or a soil sample or a pharmaceutical or food sample.

3. The method according to any one of claim 1 to 2,

wherein the surface of the sample (2) is machined such that the sample (2) partly forms an aerosol.

4. The method according to claim 1 to 3,

wherein the sample (2) is provided in the form of a solid cylinder.

5. The method according to claim 4, wherein the method comprises,

wherein the solid cylinder is obtained by surface drilling.

6. The method according to claim 1 to 5,

wherein the sample (2) is formed into an aerosol form by exposure to mechanical processing, light, electricity and/or sound waves.

7. A system (1) for analyzing a sample (2), comprising a plasma spectrometer (21) and an analysis device (22), wherein the sample (2) is a solid sample and comprises a first chemical element and a second chemical element, wherein the plasma spectrometer (21) is configured to ionize the sample (2) by means of a plasma (6) thereby generating ions and/or photons, and to analyze the generated ions and/or photons, wherein the analysis device (22) is configured to determine the concentration of the first chemical element, wherein the sample (2) is provided to the plasma spectrometer (21) in the form of an aerosol, wherein the system (1) is configured to perform the method according to any of the preceding claims.

8. The system (1) according to claim 7,

wherein the plasma spectrometer (21) and the analysis device (22) are arranged such that the same area or portion of the sample (2) is analyzed by either device (21, 22).

9. The system (1) according to any one of claims 7-8,

wherein the system (1) comprises a sample unit (36), the sample unit (36) being configured to move the sample (2) in one direction, wherein the analysis device (22) and the plasma spectrometer (21) are arranged in the direction such that the same area or portion of the sample (2) is continuously analyzed by either device (21, 22).

10. The system (1) according to any one of claims 7-9,

wherein the system (1) comprises a cleaning unit (26), the cleaning unit (26) being configured to clean and/or dry the sample (2) before providing the sample (2) to the analysis device (22) and/or the plasma spectrometer (21).

11. The system (1) according to claims 7-10,

wherein the analysis device (22) is configured to determine the concentration of the first chemical element with high accuracy, in particular with an accuracy of less than 3% relative standard deviation.

12. The system (1) according to any one of claims 7-11,

wherein the plasma spectrometer (21) is configured to determine a concentration of the second element in a concentration range that is not or only partially available to the analysis device (22).

13. The system (1) according to any one of claims 7-12,

wherein the plasma spectrometer (21) is configured to aspirate the sample (2) in the form of an aerosol through the plasma (6).

14. The system (1) according to any one of claims 7-13,

the plasma spectrometer (21) is a microwave inductively coupled atmospheric plasma mass spectrometer, a microwave inductively coupled atmospheric plasma optical emission spectrometer, a radio frequency inductively coupled mass spectrometer, a radio frequency inductively coupled optical spectrometer, a glow discharge mass spectrometer or a glow discharge optical spectrometer.

15. The system (1) according to any one of claims 7-14,

wherein the analysis device (22) is an X-ray fluorescence spectrometer, a laser induced breakdown spectrometer or an X-ray diffractometer.