Sample analyzing device

Abstract

A sample analysis apparatus that quantifies an analyte component in a sample, comprising: a storage unit (41) in which information is stored that associates, for each of a plurality of known components, an amount of the component with a type and an amount of a washing liquid for removing the component; a quantitative analysis unit (42) that introduces a plurality of samples in a predetermined order and quantifies an analyte component contained in each sample; a washing liquid introduction unit (13, 14) that introduces a washing liquid for washing the plurality of known components; and a washing execution unit (43) that, each time an analyte component contained in one sample is quantified by the quantitative analysis unit, determines a type and an amount of a washing liquid by collating information on the analyte component quantified by the quantitative analysis unit with the information stored in the storage unit, and operates the washing liquid introduction unit to perform a washing operation to remove the analyte component from the analysis apparatus.

Description

TECHNICAL FIELD

[0001] The present invention relates to a sample analysis apparatus that quantifies an analyte component contained in a sample.BACKGROUND ART

[0002] An inductively coupled plasma mass spectrometry apparatus is used to quantify harmful metal elements and the like contained in liquid samples such as environmental water collected from rivers and lakes, or drinking water (see, for example, Patent Literature 1). The inductively coupled plasma mass spectrometry apparatus includes an inductively coupled plasma ion source and a mass analysis unit. In the inductively coupled plasma ion source, inductively coupled plasma is generated from argon gas, and a nebulized liquid sample is introduced into the plasma, thereby generating atomic ions from the components contained in the liquid sample. The atomic ions generated in the inductively coupled plasma ion source are introduced into the mass analysis unit, then separated according to their mass-to-charge ratio, and detected by an ion detector.

[0003] Since the inductively coupled plasma mass spectrometry apparatus has high sensitivity, it is suitable for the detection and quantification of trace elements. On the other hand, if an element contained in a previously analyzed sample remains in the apparatus, carryover is likely to occur. Therefore, when continuously analyzing a plurality of samples, each time one sample is analyzed, a washing liquid corresponding to the type and amount of elements expected to be contained in the sample based on its attributes (tap water, river water, etc.) is introduced into the apparatus to wash the apparatus.CITATION LIST PATENT LITERATURE

[0004] [Patent Literature 1] Japanese Unexamined Patent Application Publication No. 2017-156332 [Patent Literature 2] Japanese Unexamined Patent Application Publication No. 2001-324476 SUMMARY OF INVENTION TECHNICAL PROBLEM

[0005] In actual analysis, to reliably prevent carryover, an excessive amount of washing liquid may be supplied by overestimating the amount of elements contained in the sample, or a washing liquid corresponding to an element may be supplied in consideration of the possibility that the element is contained, even if it is unlikely to be actually contained. Increasing the supply amount and types of the washing liquid in this manner increases the time required for washing. In an inductively coupled plasma mass spectrometry apparatus, it is common to continuously analyze several hundred samples. For example, if the time required for one washing is extended by just 30 seconds, the time required for a series of analyses becomes longer by several hours.

[0006] Although the problem in the prior art has been described here using an inductively coupled plasma mass spectrometry apparatus as an example, other sample analysis apparatuses that quantify an analyte component contained in a sample have had the same problem as described above.

[0007] An object of the present invention is to shorten the time required for continuous analysis while preventing carryover when continuously analyzing a plurality of samples.SOLUTION TO PROBLEM

[0008] The present invention, made to solve the above problem, is a sample analysis apparatus that quantifies an analyte component contained in a sample, the apparatus comprising: a storage unit in which information is stored that associates, for each of a plurality of known components that may be contained in a sample, an amount of the known component with a type and an amount of a washing liquid for removing the known component; a quantitative analysis unit that introduces a plurality of samples into the sample analysis apparatus in a predetermined order and quantifies an analyte component contained in each sample; a washing liquid introduction unit that introduces a washing liquid for washing the plurality of known components into the sample analysis apparatus; and a washing execution unit that, each time an analyte component contained in one sample is quantified by the quantitative analysis unit, determines a type and an amount of a washing liquid by collating information on the analyte component quantified by the quantitative analysis unit with the information stored in the storage unit, and operates the washing liquid introduction unit to perform a washing operation to remove the analyte component from the sample analysis apparatus.ADVANTAGEOUS EFFECTS OF INVENTION

[0009] In the sample analysis apparatus according to the present invention, information that associates, for each of a plurality of known components, an amount of the known component with a type and an amount of a washing liquid for removing the known component is stored in advance in a storage unit. Then, each time the quantitative analysis unit quantifies an analyte component contained in one sample, the washing execution unit determines a type and an amount of a washing liquid by collating information on the quantified analyte component with the information stored in the storage unit, operates the washing liquid introduction unit, and performs a washing operation to remove the analyte component from the sample analysis apparatus using the washing liquid of that type and amount. Therefore, it is possible to wash the sample analysis apparatus using a washing liquid of an appropriate type and amount according to the amount of the analyte component contained in the sample analyzed immediately before, thereby preventing carryover. In the sample analysis apparatus according to the present invention, an excessive amount of washing liquid is not supplied by overestimating the amount of elements contained in the sample, and a washing operation using a washing liquid for washing components not contained in the sample is not performed, so the time required for continuously analyzing a plurality of samples can be shortened.BRIEF DESCRIPTION OF DRAWINGS

[0010] [FIG. 1] FIG. 1 is a schematic configuration diagram of an inductively coupled plasma mass spectrometry apparatus which is an embodiment of the sample analysis apparatus according to the present invention. [FIG. 2] FIG. 2 is an example of information regarding washing liquids used in the inductively coupled plasma mass spectrometry apparatus of the present embodiment. [FIG. 3] FIG. 3 is a flowchart showing a procedure for continuously measuring a plurality of samples in the inductively coupled plasma mass spectrometry apparatus of the present embodiment. [FIG. 4] FIG. 4 is another example of information regarding washing liquids used in the inductively coupled plasma mass spectrometry apparatus of the present embodiment. DESCRIPTION OF EMBODIMENTS

[0011] An inductively coupled plasma mass spectrometry apparatus (ICP-MS), which is an embodiment of the sample analysis apparatus according to the present invention, will be described below with reference to the drawings.

[0012] FIG. 1 is a schematic configuration diagram of an inductively coupled plasma mass spectrometry apparatus 1 of the present embodiment. This inductively coupled plasma mass spectrometry apparatus 1 includes a plasma ionization unit 10, a mass analysis unit 30, and a control / processing unit 40.

[0013] The plasma ionization unit 10 has a plasma torch 20 in which a sample flow tube through which a liquid sample nebulized by a nebulizer gas flows, a plasma gas tube formed on the outer periphery of the sample flow tube, and a cooling gas tube formed on its further outer periphery are formed. Connected to the sample flow tube are an autosampler 11 that introduces a liquid sample, a nebulizer gas supply source 12 that supplies a nebulizer gas to nebulize the liquid sample introduced from the autosampler 11, and a washing liquid introduction unit 13 that introduces a washing liquid. A flow path switching valve 14 is disposed at a connection part where a flow path from the washing liquid introduction unit 13 is connected in the middle of a flow path from the autosampler 11 to the sample flow tube, to switch the flow path so as to selectively connect the autosampler 11 and the washing liquid introduction unit 13 to the sample introduction tube.

[0014] A plasma gas supply source 15 is connected to the plasma gas tube. A cooling gas supply source (not shown) that supplies cooling gas is connected to the cooling gas tube. For example, argon gas is used for the nebulizer gas, the cooling gas, and the plasma gas. In the plasma ionization unit 10, an argon plasma 21 is generated at the tip of the plasma torch 20, and a nebulized liquid sample is introduced into the argon plasma 21 to generate atomic ions from the liquid sample.

[0015] The mass analysis unit 30 includes a first vacuum chamber 31 having a skimmer formed at an inlet facing the argon plasma 21, and a second vacuum chamber 32 in which a skimmer is formed between it and the first vacuum chamber 31, and in which a quadrupole mass filter 321 and a detector 322 for detecting ions separated by the quadrupole mass filter 321 are disposed.

[0016] The control / processing unit 40 includes a storage unit 41, and as functional blocks, a quantitative analysis unit 42, a washing execution unit 43, and a washing setting change unit 44. The control / processing unit 40 is actually a personal computer, and the aforementioned functional blocks are realized by a processor executing a dedicated program installed in advance. An input unit 60 such as a keyboard or a mouse and a display unit 70 such as a liquid crystal display are connected to the control / processing unit 40.

[0017] The storage unit 41 stores information on measurement conditions for elements to be measured (mass-to-charge ratio of ions generated from the element, mass-to-charge ratio of target ions in SIM measurement, interfering ions, etc.). The elements to be measured may include, in addition to the element to be quantified (element to be quantified), elements that need to be measured to quantify the element to be quantified (related elements that generate interfering ions for the element to be quantified). The target ion in SIM measurement is determined based on the fact that it is not affected (or the effect is small) by interfering ions derived from other elements, and that the detection sensitivity is high (for example, Patent Literature 1).

[0018] The storage unit 41 also stores calibration curve data representing the relationship between the measured intensity and the concentration of the target ion for each element to be measured. The calibration curve is created, for example, by the user performing a preliminary measurement using a standard sample or the like prepared for each element to be measured in consideration of the attributes of the sample to be analyzed, and information on the minimum concentration (quantification lower limit value) and the maximum concentration expected to be contained in the sample (quantification upper limit value) is added. The maximum concentration is the maximum concentration expected to be contained in the sample, and is usually determined by the user based on the attributes of the sample and the content of pretreatment.

[0019] Furthermore, the storage unit 41 also stores information on the washing liquid used to wash the plasma ionization unit 10 and the mass analysis unit 30. Specifically, information on a standard washing liquid (type of washing liquid and supply time), a threshold value for the concentration of each element to be measured, and information on an additional washing liquid for each element to be measured (type of washing liquid and supply time) are stored.

[0020] FIG. 2 is an example of information on the washing liquid. In this example, as information on the standard washing liquid, it is set that washing liquid a is supplied for 30 seconds, washing liquid b for 30 seconds, and washing liquid c for 30 seconds, in order. As information on the additional washing liquid, it is set that when the concentration of element A exceeds a threshold value (100 ppm), washing liquid a is additionally supplied for 30 seconds; when the concentration of element B exceeds a threshold value (200 ppm), washing liquid b' is additionally supplied for 20 seconds; when the concentration of element C exceeds a threshold value (100 ppm), washing liquid c is additionally supplied for 30 seconds; and when the concentration of element D exceeds a threshold value (150 ppm), washing liquid c is additionally supplied for 20 seconds, etc. Note that washing liquid b' is the same type of washing liquid as washing liquid b, but with a higher concentration. The information on the additional washing liquid may be set for all elements, or may be set for only some of the elements. In the latter case, the threshold value for the concentration of the element may be set, for example, to the maximum concentration of the calibration curve or to infinity. For the washing liquid, a solvent such as hydrochloric acid, nitric acid, or hydrofluoric acid, which is used to dissolve the elements to be measured such as metals contained in the sample, is usually used. Although these are all acidic solvents, pure water, an alkaline solvent, an organic solvent, or the like may also be used.

[0021] Next, a procedure for continuously analyzing a plurality of liquid samples using the inductively coupled plasma mass spectrometry apparatus 1 of the present embodiment will be described with reference to the flowchart of FIG. 3. Here, the case of quantifying elements by the calibration curve method is described as an example, but in the case of quantifying elements by the internal standard method, an internal standard element is associated with the element to be quantified in advance, and a prescribed amount of the internal standard element is added to each sample (for example, Patent Literature 2).

[0022] The user sets a plurality of samples to be analyzed in the autosampler 11 in advance. Further, the user sets washing liquid a, washing liquid b, washing liquid b', washing liquid c, washing liquid d, ... in the washing liquid introduction unit 13.

[0023] After setting the samples in the autosampler 11, when the user instructs the execution of measurement through a predetermined operation via the input unit 60, the quantitative analysis unit 42 displays a screen for specifying the element to be quantified on the display unit 70. When the user specifies the element to be quantified, the quantitative analysis unit 42 determines the specified element to be quantified and related elements of that element to be quantified as the elements to be measured, and reads out the measurement conditions for those elements to be measured and the information on the washing liquid corresponding to each element from the storage unit 41. In the following description, elements A, B, C, and D are assumed to be the elements to be measured.

[0024] When the measurement conditions of the elements to be measured and the information on the washing liquid are read out, the washing setting change unit 44 displays the read-out information on the washing liquid on the screen of the display unit 70. The content displayed at this time is what is stored in the storage unit 41, for example, what was set by the apparatus administrator at the time of installation of the apparatus, or what was changed and stored during subsequent analyses. The user confirms the displayed content of the washing liquid, makes changes as necessary, and then determines the information on the washing liquid (Step 1). When a change is made by the user, the washing setting change unit 44 stores the changed information on the washing liquid in the storage unit 41.

[0025] When the information on the washing liquid is determined by the user, the quantitative analysis unit 42 supplies the first sample set at a predetermined position of the autosampler 11 to the sample introduction tube. In parallel with this, the nebulizer gas supply source 12 also supplies nebulizer gas to the sample introduction tube, the plasma gas supply source 15 supplies plasma gas to the plasma gas tube, and further, the cooling gas supply source supplies cooling gas to the cooling gas tube.

[0026] The sample supplied to the sample introduction tube and nebulized by the nebulizer gas is introduced into the argon plasma 21 generated at the tip of the plasma torch 20 to generate atomic ions. The generated atomic ions are introduced into the mass analysis unit 30, mass-separated by the quadrupole mass filter 321, and then detected by the detector 322. In the mass analysis unit 30, SIM measurement is performed on ions (target ions) of a predetermined mass-to-charge ratio for each of the elements to be quantitatively analyzed, A, B, C, and D. This is the case where there are no interfering ions for any of elements A, B, C, and D. If an interfering ion (an isobaric ion with respect to the ion of the element) exists for any of the elements, an ion of another mass-to-charge ratio corresponding to the isobaric ion is also subjected to SIM measurement. Alternatively, when the number of elements to be quantitatively analyzed is large, etc., MS scan measurement may be performed.

[0027] When the measurement of the sample is completed (Step 2), the quantitative analysis unit 42 reads out the calibration curves for elements A, B, C, and D stored in the storage unit 41. Then, the concentration value (calculates the quantitative value) for each of elements A, B, C, and D is determined by comparing the measured intensity in the SIM measurement of the target ion of each of elements A, B, C, and D with the calibration curve (Step 3).

[0028] When the concentration values for elements A, B, C, and D are determined, the washing execution unit 43 compares the concentration value of each element with the threshold value for each element stored in the storage unit 41. Then, if the concentration of any of the elements is below the threshold value (NO in Step 4), the washing execution unit 43 operates the washing liquid introduction unit 13 and the flow path switching valve 14, and washes the plasma ionization unit 10 and the mass analysis unit 30 using the standard washing liquid based on the information stored in the storage unit 41 (Step 5). On the other hand, if the concentration value of any of the elements exceeds the threshold value (YES in Step 4), the washing execution unit 43 operates the washing liquid introduction unit 13 and the flow path switching valve 14, washes the plasma ionization unit 10 and the mass analysis unit 30 using the standard washing liquid, and further washes the plasma ionization unit 10 and the mass analysis unit 30 using the additional washing liquid based on the information stored in the storage unit 41 (Step 6).

[0029] Specifically, for example, if the concentration value of element A exceeds the threshold value (100 ppm), after washing with the standard washing liquid, washing liquid a is further passed for 30 seconds. If the concentration values of both element A and element B exceed their threshold values (element A: 100 ppm, element B: 200 ppm), after washing with the standard washing liquid, washing liquid a is further passed for 30 seconds, and washing liquid b' is passed for 20 seconds. If the concentration values of elements for which the additional washing liquid is common exceed the threshold values, the additional washing liquid of the element with the longer supply time (or larger supply amount) is supplied. In this example, if the concentration values of both element A and element C exceed the threshold values, after executing the washing operation with the standard washing liquid, an additional washing operation is executed by further passing washing liquid a for 40 seconds.

[0030] When the washing operation by the washing execution unit 43 is completed, the quantitative analysis unit 42 checks whether the measurement of all samples has been completed. At this point, only the first sample has been measured, and unmeasured samples remain (NO in Step 7), so the process returns to Step 2 to measure the next sample. If the measurement of all samples has been completed (YES in Step 7), the series of measurement operations is terminated.

[0031] Since the inductively coupled plasma mass spectrometry apparatus has high sensitivity, it is suitable for detecting and quantifying trace elements, but on the other hand, carryover is likely to occur if elements contained in a previously measured sample remain. Therefore, to reliably prevent carryover, an excessive amount of washing liquid may be supplied by overestimating the amount of elements contained in the sample, or a washing liquid corresponding to an element may be supplied in consideration of the possibility that the element is contained, even if it is unlikely to be actually contained.

[0032] In contrast, in the inductively coupled plasma mass spectrometry apparatus 1 of the present embodiment, each time the elements to be measured contained in one sample are quantified, the concentration value of each element is determined (quantified). Then, if the concentration value (quantitative value) of none of the elements exceeds the threshold value, the inside of the apparatus is washed using only the standard washing liquid, and only when the concentration value (quantitative value) of any of the elements exceeds the threshold value, an additional washing is performed using a washing liquid of a type and amount corresponding to that element. Therefore, it is possible to wash the sample analysis apparatus using a washing liquid of an appropriate type and amount according to the amount of the analyte component contained in the sample analyzed immediately before, thereby preventing carryover. In the inductively coupled plasma mass spectrometry apparatus 1 of the present embodiment, an excessive amount of washing liquid is not supplied by overestimating the amount of elements contained in the sample, and a washing operation using a washing liquid for washing elements not contained in the sample is not performed, so the time required for continuously analyzing a plurality of samples can be shortened compared to the prior art.

[0033] In the above embodiment, the configuration is such that when the concentration of none of the elements to be measured exceeds the threshold value, the inside of the apparatus is washed using only the standard washing liquid, and when the concentration of any element exceeds the threshold value, washing is performed using an additional washing liquid. However, other configurations can also be adopted. Some examples of such configurations will be described below. The configurations described below can be executed by the washing setting change unit 44 changing the settings related to the washing of the apparatus in response to a predetermined input operation by the user.

[0034] In the above example, the threshold value is set as a concentration value (absolute value), but it may also be set as a ratio based on the maximum concentration in the calibration curve for each element. Specifically, for example, a common threshold value can be set for elements A, B, C, and D as 80% of the maximum concentration in the calibration curve. Alternatively, it can be configured such that for each of elements A, B, C, and D, threshold values are set individually as 80%, 70%, 75%, and 95% of the maximum concentration in the calibration curve. In this case, information on the washing liquid as shown in FIG. 4, for example, may be stored in the storage unit 41 in advance.

[0035] In all of the above examples, one type of washing liquid is associated with each element, but a plurality of washing liquids may be associated with one element. For example, a washing sequence may be set such that when the concentration value of element E exceeds a threshold value, in addition to washing with the standard washing liquid, the apparatus is washed by sequentially passing washing liquid A for 30 seconds, washing liquid B for 20 seconds, and pure water for 30 seconds, and when the concentration value of element F exceeds a threshold value, in addition to washing with the standard washing liquid, the apparatus is washed by sequentially passing washing liquid A for 40 seconds, washing liquid C for 30 seconds, and pure water for 30 seconds. By setting such a washing sequence for one or more elements that tend to remain in the flow paths, etc., within the apparatus, a washing operation using a plurality of washing liquids is executed, and such elements can be more reliably removed from the apparatus.

[0036] Alternatively, instead of the information of a standard washing liquid and an additional washing liquid, the washing liquid associated with each element may be supplied for a time (amount) corresponding to the quantitative value of the element. In that case, for example, for each element, information representing the relationship between the quantitative value of the element and the amount or supply time of the washing liquid (for example, a mathematical formula for finding the amount or supply time of the washing liquid with the quantitative value as a variable) may be stored in the storage unit 41, and the washing execution unit 43 may determine the amount or supply time of the washing liquid based on that mathematical formula. In this case, the inside of the apparatus can be washed with different amounts of washing liquid according to the concentration (quantitative value) of the element actually contained in the sample. When a common washing liquid is associated with a plurality of elements, the longest of the supply times of the washing liquid calculated from the mathematical formulas corresponding to each of the plurality of elements may be adopted.

[0037] The above embodiment is an example, and can be modified as appropriate in line with the spirit of the present invention.

[0038] Although the above embodiment is an inductively coupled plasma mass spectrometry apparatus, the same configuration as described above can also be adopted in an apparatus that detects atomic ions generated by an inductively coupled plasma ion source by another measurement method. Furthermore, the same configuration as described above can be adopted in various analysis apparatuses that use other ion sources, or in apparatuses that perform analysis without generating ions from the sample to be analyzed, and that perform analysis to quantify components contained in a sample for a plurality of samples. In particular, like the inductively coupled plasma mass spectrometry apparatus, the same configuration as described above can be suitably used in an atomic absorption spectrometry apparatus or the like that quantifies trace elements contained in a sample.

[0039] Further, in the above embodiment, only one threshold value is set for each element, but a plurality of threshold values may be set, and each time each threshold value is exceeded, a washing operation using the type and amount (or supply time) of a preset additional washing liquid may be executed.

[0040] [Aspects] It will be apparent to those skilled in the art that the exemplary embodiments described above are specific examples of the following aspects.

[0041] (Item 1) One aspect of the present invention is a sample analysis apparatus that quantifies an analyte component contained in a sample, the apparatus comprising: a storage unit in which information is stored that associates, for each of a plurality of known components that may be contained in a sample, an amount of the known component with a type and an amount of a washing liquid for removing the known component; a quantitative analysis unit that introduces a plurality of samples into the sample analysis apparatus in a predetermined order and quantifies an analyte component contained in each sample; a washing liquid introduction unit that introduces a washing liquid for washing the plurality of known components into the sample analysis apparatus; and a washing execution unit that, each time an analyte component contained in one sample is quantified by the quantitative analysis unit, determines a type and an amount of a washing liquid by collating information on the analyte component quantified by the quantitative analysis unit with the information stored in the storage unit, and operates the washing liquid introduction unit to perform a washing operation to remove the analyte component from the sample analysis apparatus.

[0042] In the sample analysis apparatus according to Item 1, information that associates, for each of a plurality of known components, an amount of the known component with a type and an amount of a washing liquid for removing the known component is stored in advance in a storage unit. Then, each time the quantitative analysis unit quantifies an analyte component contained in one sample, the washing execution unit determines a type and an amount of a washing liquid by collating information on the quantified analyte component with the information stored in the storage unit, operates the washing liquid introduction unit, and performs a washing operation to remove the analyte component from the sample analysis apparatus using the washing liquid of that type and amount. Therefore, it is possible to wash the sample analysis apparatus using a washing liquid of an appropriate type and amount according to the amount of the analyte component contained in the sample analyzed immediately before, thereby preventing carryover. In the sample analysis apparatus according to Item 1, an excessive amount of washing liquid is not supplied by overestimating the amount of elements contained in the sample, and a washing operation using a washing liquid for washing elements not contained in the sample is not performed, so the time required for continuously analyzing a plurality of samples can be shortened. Although the analyte component is often plural, the analyte component may be one.

[0043] (Item 2) The sample analysis apparatus according to Item 2 is the sample analysis apparatus according to Item 1, wherein the storage unit further stores information on a type and an amount of a standard washing liquid, information on a threshold value associated with each of the plurality of known components, and information on a type and an amount of an additional washing liquid to be used when the threshold value is exceeded, and the washing execution unit performs a washing operation using the standard washing liquid when a quantitative value of the analyte component does not exceed a threshold value associated with the analyte component, and executes a washing operation using the additional washing liquid associated with the analyte component in addition to the washing operation using the standard washing liquid when the quantitative value of the analyte component exceeds the threshold value associated with the analyte component.

[0044] In the sample analysis apparatus according to Item 2, for each of the analyte components, the apparatus can be washed with a washing liquid of an appropriate type and amount based on whether the quantitative value exceeds a threshold value. When the concentration values of components for which the additional washing liquid is common exceed the threshold values, the additional washing liquid of the component with the larger supply amount may be supplied.

[0045] (Item 3) The sample analysis apparatus according to Item 3 is the sample analysis apparatus according to Item 2, wherein the storage unit further stores information on a calibration curve and a maximum concentration for each of the plurality of known components, and the threshold value is set as a ratio with respect to the maximum concentration.

[0046] (Item 4) The sample analysis apparatus according to Item 4 is the sample analysis apparatus according to Item 3, wherein the ratio is set individually for the plurality of known components.

[0047] When a calibration curve is used for the quantification of a component contained in a sample, it is common to store information on a minimum concentration representing the quantification lower limit of the component and a maximum concentration expected to be contained in the sample, together with the calibration curve. In the sample analysis apparatus according to Item 3, a threshold value is set as a ratio with respect to the maximum concentration thus stored, and the apparatus can be washed with a washing liquid of an appropriate type and amount. At this time, the ratio with respect to the maximum concentration may be a common value for a plurality of known components, or may be set individually as in the sample analysis apparatus according to Item 4. In the latter case, the threshold value can be set more finely.

[0048] (Item 5) The sample analysis apparatus according to Item 5 is the sample analysis apparatus according to any one of Items 1 to 4, wherein the storage unit further stores information representing a relationship between a quantitative value of the plurality of known components and an amount of the washing liquid, and the washing execution unit executes a washing operation using an amount of washing liquid corresponding to the quantitative value of the analyte component.

[0049] In the sample analysis apparatus according to Item 5, for each of the known components, information representing the relationship between the quantitative value of the component and the amount or supply time of the washing liquid (for example, a mathematical formula for finding the amount or supply time of the washing liquid with the quantitative value as a variable) is stored in the storage unit, and the washing execution unit determines the amount or supply time of the washing liquid based on that mathematical formula. In the sample analysis apparatus according to Item 5, the inside of the apparatus can be washed with different amounts of washing liquid according to the concentration (quantitative value) of the element actually contained in the sample. When a common washing liquid is associated with a plurality of components, the longest of the supply times of the washing liquid calculated from the mathematical formulas corresponding to the plurality of components may be adopted.

[0050] (Item 6) The sample analysis apparatus according to Item 6 is the sample analysis apparatus according to any one of Items 1 to 5, wherein for at least one of the plurality of known components, a threshold value for the amount of the known component, and a washing sequence for executing a washing operation using a plurality of washing liquids in order when a quantitative value of the known component exceeds the threshold value, are set.

[0051] In the sample analysis apparatus according to Item 6, for example, for a component that tends to remain in the apparatus, by executing a washing operation using a plurality of washing liquids, that component can be more reliably removed from the apparatus.

[0052] (Item 7) The sample analysis apparatus according to Item 7 is the sample analysis apparatus according to any one of Items 1 to 5, wherein the quantitative analysis unit includes an inductively coupled plasma ion source that generates atomic ions from a component contained in the sample using inductively coupled plasma.

[0053] An analysis apparatus that detects a trace amount of a component contained in a sample with high sensitivity is more prone to carryover, and it is more often the case that an excessive amount of washing liquid is supplied by overestimating the amount of elements contained in the sample, or a washing operation using a washing liquid for washing elements not contained in the sample is performed. Therefore, the configuration of the sample analysis apparatus according to any one of Items 1 to 6 can be suitably used. As one such sample analysis apparatus, an analysis apparatus including an inductively coupled plasma ion source as described in Item 7 can be mentioned.REFERENCE SIGNS LIST

[0054] 1... Inductively coupled plasma mass spectrometry apparatus 10... Plasma ionization unit 11... Autosampler 12... Nebulizer gas supply source 13... Washing liquid introduction unit 14... Flow path switching valve 15... Plasma gas supply source 20... Plasma torch 21... Argon plasma 30... Mass analysis unit 31... First vacuum chamber 32... Second vacuum chamber 321... Quadrupole mass filter 322... Detector 40... Control / processing unit 41... Storage unit 42... Quantitative analysis unit 43... Washing execution unit 44... Washing setting change unit 60... Input unit 70... Display unit

Examples

Embodiment Construction

[0011]An inductively coupled plasma mass spectrometry apparatus (ICP-MS), which is an embodiment of the sample analysis apparatus according to the present invention, will be described below with reference to the drawings.

[0012]FIG. 1 is a schematic configuration diagram of an inductively coupled plasma mass spectrometry apparatus 1 of the present embodiment. This inductively coupled plasma mass spectrometry apparatus 1 includes a plasma ionization unit 10, a mass analysis unit 30, and a control / processing unit 40.

[0013]The plasma ionization unit 10 has a plasma torch 20 in which a sample flow tube through which a liquid sample nebulized by a nebulizer gas flows, a plasma gas tube formed on the outer periphery of the sample flow tube, and a cooling gas tube formed on its further outer periphery are formed. Connected to the sample flow tube are an autosampler 11 that introduces a liquid sample, a nebulizer gas supply source 12 that supplies a nebulizer gas to nebulize the liquid sampl...

TECHNICAL FIELD

[0001] The present invention relates to a sample analysis apparatus that quantifies an analyte component contained in a sample.BACKGROUND ART

[0002] An inductively coupled plasma mass spectrometry apparatus is used to quantify harmful metal elements and the like contained in liquid samples such as environmental water collected from rivers and lakes, or drinking water (see, for example, Patent Literature 1). The inductively coupled plasma mass spectrometry apparatus includes an inductively coupled plasma ion source and a mass analysis unit. In the inductively coupled plasma ion source, inductively coupled plasma is generated from argon gas, and a nebulized liquid sample is introduced into the plasma, thereby generating atomic ions from the components contained in the liquid sample. The atomic ions generated in the inductively coupled plasma ion source are introduced into the mass analysis unit, then separated according to their mass-to-charge ratio, and detected by an ion detector.

[0003] Since the inductively coupled plasma mass spectrometry apparatus has high sensitivity, it is suitable for the detection and quantification of trace elements. On the other hand, if an element contained in a previously analyzed sample remains in the apparatus, carryover is likely to occur. Therefore, when continuously analyzing a plurality of samples, each time one sample is analyzed, a washing liquid corresponding to the type and amount of elements expected to be contained in the sample based on its attributes (tap water, river water, etc.) is introduced into the apparatus to wash the apparatus.CITATION LIST PATENT LITERATURE

[0004] [Patent Literature 1] Japanese Unexamined Patent Application Publication No. 2017-156332 [Patent Literature 2] Japanese Unexamined Patent Application Publication No. 2001-324476 SUMMARY OF INVENTION TECHNICAL PROBLEM

[0005] In actual analysis, to reliably prevent carryover, an excessive amount of washing liquid may be supplied by overestimating the amount of elements contained in the sample, or a washing liquid corresponding to an element may be supplied in consideration of the possibility that the element is contained, even if it is unlikely to be actually contained. Increasing the supply amount and types of the washing liquid in this manner increases the time required for washing. In an inductively coupled plasma mass spectrometry apparatus, it is common to continuously analyze several hundred samples. For example, if the time required for one washing is extended by just 30 seconds, the time required for a series of analyses becomes longer by several hours.

[0006] Although the problem in the prior art has been described here using an inductively coupled plasma mass spectrometry apparatus as an example, other sample analysis apparatuses that quantify an analyte component contained in a sample have had the same problem as described above.

[0007] An object of the present invention is to shorten the time required for continuous analysis while preventing carryover when continuously analyzing a plurality of samples.SOLUTION TO PROBLEM

[0008] The present invention, made to solve the above problem, is a sample analysis apparatus that quantifies an analyte component contained in a sample, the apparatus comprising: a storage unit in which information is stored that associates, for each of a plurality of known components that may be contained in a sample, an amount of the known component with a type and an amount of a washing liquid for removing the known component; a quantitative analysis unit that introduces a plurality of samples into the sample analysis apparatus in a predetermined order and quantifies an analyte component contained in each sample; a washing liquid introduction unit that introduces a washing liquid for washing the plurality of known components into the sample analysis apparatus; and a washing execution unit that, each time an analyte component contained in one sample is quantified by the quantitative analysis unit, determines a type and an amount of a washing liquid by collating information on the analyte component quantified by the quantitative analysis unit with the information stored in the storage unit, and operates the washing liquid introduction unit to perform a washing operation to remove the analyte component from the sample analysis apparatus.ADVANTAGEOUS EFFECTS OF INVENTION

[0009] In the sample analysis apparatus according to the present invention, information that associates, for each of a plurality of known components, an amount of the known component with a type and an amount of a washing liquid for removing the known component is stored in advance in a storage unit. Then, each time the quantitative analysis unit quantifies an analyte component contained in one sample, the washing execution unit determines a type and an amount of a washing liquid by collating information on the quantified analyte component with the information stored in the storage unit, operates the washing liquid introduction unit, and performs a washing operation to remove the analyte component from the sample analysis apparatus using the washing liquid of that type and amount. Therefore, it is possible to wash the sample analysis apparatus using a washing liquid of an appropriate type and amount according to the amount of the analyte component contained in the sample analyzed immediately before, thereby preventing carryover. In the sample analysis apparatus according to the present invention, an excessive amount of washing liquid is not supplied by overestimating the amount of elements contained in the sample, and a washing operation using a washing liquid for washing components not contained in the sample is not performed, so the time required for continuously analyzing a plurality of samples can be shortened.BRIEF DESCRIPTION OF DRAWINGS

[0010] [FIG. 1] FIG. 1 is a schematic configuration diagram of an inductively coupled plasma mass spectrometry apparatus which is an embodiment of the sample analysis apparatus according to the present invention. [FIG. 2] FIG. 2 is an example of information regarding washing liquids used in the inductively coupled plasma mass spectrometry apparatus of the present embodiment. [FIG. 3] FIG. 3 is a flowchart showing a procedure for continuously measuring a plurality of samples in the inductively coupled plasma mass spectrometry apparatus of the present embodiment. [FIG. 4] FIG. 4 is another example of information regarding washing liquids used in the inductively coupled plasma mass spectrometry apparatus of the present embodiment. DESCRIPTION OF EMBODIMENTS

[0011] An inductively coupled plasma mass spectrometry apparatus (ICP-MS), which is an embodiment of the sample analysis apparatus according to the present invention, will be described below with reference to the drawings.

[0012] FIG. 1 is a schematic configuration diagram of an inductively coupled plasma mass spectrometry apparatus 1 of the present embodiment. This inductively coupled plasma mass spectrometry apparatus 1 includes a plasma ionization unit 10, a mass analysis unit 30, and a control / processing unit 40.

[0013] The plasma ionization unit 10 has a plasma torch 20 in which a sample flow tube through which a liquid sample nebulized by a nebulizer gas flows, a plasma gas tube formed on the outer periphery of the sample flow tube, and a cooling gas tube formed on its further outer periphery are formed. Connected to the sample flow tube are an autosampler 11 that introduces a liquid sample, a nebulizer gas supply source 12 that supplies a nebulizer gas to nebulize the liquid sample introduced from the autosampler 11, and a washing liquid introduction unit 13 that introduces a washing liquid. A flow path switching valve 14 is disposed at a connection part where a flow path from the washing liquid introduction unit 13 is connected in the middle of a flow path from the autosampler 11 to the sample flow tube, to switch the flow path so as to selectively connect the autosampler 11 and the washing liquid introduction unit 13 to the sample introduction tube.

[0014] A plasma gas supply source 15 is connected to the plasma gas tube. A cooling gas supply source (not shown) that supplies cooling gas is connected to the cooling gas tube. For example, argon gas is used for the nebulizer gas, the cooling gas, and the plasma gas. In the plasma ionization unit 10, an argon plasma 21 is generated at the tip of the plasma torch 20, and a nebulized liquid sample is introduced into the argon plasma 21 to generate atomic ions from the liquid sample.

[0015] The mass analysis unit 30 includes a first vacuum chamber 31 having a skimmer formed at an inlet facing the argon plasma 21, and a second vacuum chamber 32 in which a skimmer is formed between it and the first vacuum chamber 31, and in which a quadrupole mass filter 321 and a detector 322 for detecting ions separated by the quadrupole mass filter 321 are disposed.

[0016] The control / processing unit 40 includes a storage unit 41, and as functional blocks, a quantitative analysis unit 42, a washing execution unit 43, and a washing setting change unit 44. The control / processing unit 40 is actually a personal computer, and the aforementioned functional blocks are realized by a processor executing a dedicated program installed in advance. An input unit 60 such as a keyboard or a mouse and a display unit 70 such as a liquid crystal display are connected to the control / processing unit 40.

[0017] The storage unit 41 stores information on measurement conditions for elements to be measured (mass-to-charge ratio of ions generated from the element, mass-to-charge ratio of target ions in SIM measurement, interfering ions, etc.). The elements to be measured may include, in addition to the element to be quantified (element to be quantified), elements that need to be measured to quantify the element to be quantified (related elements that generate interfering ions for the element to be quantified). The target ion in SIM measurement is determined based on the fact that it is not affected (or the effect is small) by interfering ions derived from other elements, and that the detection sensitivity is high (for example, Patent Literature 1).

[0018] The storage unit 41 also stores calibration curve data representing the relationship between the measured intensity and the concentration of the target ion for each element to be measured. The calibration curve is created, for example, by the user performing a preliminary measurement using a standard sample or the like prepared for each element to be measured in consideration of the attributes of the sample to be analyzed, and information on the minimum concentration (quantification lower limit value) and the maximum concentration expected to be contained in the sample (quantification upper limit value) is added. The maximum concentration is the maximum concentration expected to be contained in the sample, and is usually determined by the user based on the attributes of the sample and the content of pretreatment.

[0019] Furthermore, the storage unit 41 also stores information on the washing liquid used to wash the plasma ionization unit 10 and the mass analysis unit 30. Specifically, information on a standard washing liquid (type of washing liquid and supply time), a threshold value for the concentration of each element to be measured, and information on an additional washing liquid for each element to be measured (type of washing liquid and supply time) are stored.

[0020] FIG. 2 is an example of information on the washing liquid. In this example, as information on the standard washing liquid, it is set that washing liquid a is supplied for 30 seconds, washing liquid b for 30 seconds, and washing liquid c for 30 seconds, in order. As information on the additional washing liquid, it is set that when the concentration of element A exceeds a threshold value (100 ppm), washing liquid a is additionally supplied for 30 seconds; when the concentration of element B exceeds a threshold value (200 ppm), washing liquid b' is additionally supplied for 20 seconds; when the concentration of element C exceeds a threshold value (100 ppm), washing liquid c is additionally supplied for 30 seconds; and when the concentration of element D exceeds a threshold value (150 ppm), washing liquid c is additionally supplied for 20 seconds, etc. Note that washing liquid b' is the same type of washing liquid as washing liquid b, but with a higher concentration. The information on the additional washing liquid may be set for all elements, or may be set for only some of the elements. In the latter case, the threshold value for the concentration of the element may be set, for example, to the maximum concentration of the calibration curve or to infinity. For the washing liquid, a solvent such as hydrochloric acid, nitric acid, or hydrofluoric acid, which is used to dissolve the elements to be measured such as metals contained in the sample, is usually used. Although these are all acidic solvents, pure water, an alkaline solvent, an organic solvent, or the like may also be used.

[0021] Next, a procedure for continuously analyzing a plurality of liquid samples using the inductively coupled plasma mass spectrometry apparatus 1 of the present embodiment will be described with reference to the flowchart of FIG. 3. Here, the case of quantifying elements by the calibration curve method is described as an example, but in the case of quantifying elements by the internal standard method, an internal standard element is associated with the element to be quantified in advance, and a prescribed amount of the internal standard element is added to each sample (for example, Patent Literature 2).

[0022] The user sets a plurality of samples to be analyzed in the autosampler 11 in advance. Further, the user sets washing liquid a, washing liquid b, washing liquid b', washing liquid c, washing liquid d, ... in the washing liquid introduction unit 13.

[0023] After setting the samples in the autosampler 11, when the user instructs the execution of measurement through a predetermined operation via the input unit 60, the quantitative analysis unit 42 displays a screen for specifying the element to be quantified on the display unit 70. When the user specifies the element to be quantified, the quantitative analysis unit 42 determines the specified element to be quantified and related elements of that element to be quantified as the elements to be measured, and reads out the measurement conditions for those elements to be measured and the information on the washing liquid corresponding to each element from the storage unit 41. In the following description, elements A, B, C, and D are assumed to be the elements to be measured.

[0024] When the measurement conditions of the elements to be measured and the information on the washing liquid are read out, the washing setting change unit 44 displays the read-out information on the washing liquid on the screen of the display unit 70. The content displayed at this time is what is stored in the storage unit 41, for example, what was set by the apparatus administrator at the time of installation of the apparatus, or what was changed and stored during subsequent analyses. The user confirms the displayed content of the washing liquid, makes changes as necessary, and then determines the information on the washing liquid (Step 1). When a change is made by the user, the washing setting change unit 44 stores the changed information on the washing liquid in the storage unit 41.

[0025] When the information on the washing liquid is determined by the user, the quantitative analysis unit 42 supplies the first sample set at a predetermined position of the autosampler 11 to the sample introduction tube. In parallel with this, the nebulizer gas supply source 12 also supplies nebulizer gas to the sample introduction tube, the plasma gas supply source 15 supplies plasma gas to the plasma gas tube, and further, the cooling gas supply source supplies cooling gas to the cooling gas tube.

[0026] The sample supplied to the sample introduction tube and nebulized by the nebulizer gas is introduced into the argon plasma 21 generated at the tip of the plasma torch 20 to generate atomic ions. The generated atomic ions are introduced into the mass analysis unit 30, mass-separated by the quadrupole mass filter 321, and then detected by the detector 322. In the mass analysis unit 30, SIM measurement is performed on ions (target ions) of a predetermined mass-to-charge ratio for each of the elements to be quantitatively analyzed, A, B, C, and D. This is the case where there are no interfering ions for any of elements A, B, C, and D. If an interfering ion (an isobaric ion with respect to the ion of the element) exists for any of the elements, an ion of another mass-to-charge ratio corresponding to the isobaric ion is also subjected to SIM measurement. Alternatively, when the number of elements to be quantitatively analyzed is large, etc., MS scan measurement may be performed.

[0027] When the measurement of the sample is completed (Step 2), the quantitative analysis unit 42 reads out the calibration curves for elements A, B, C, and D stored in the storage unit 41. Then, the concentration value (calculates the quantitative value) for each of elements A, B, C, and D is determined by comparing the measured intensity in the SIM measurement of the target ion of each of elements A, B, C, and D with the calibration curve (Step 3).

[0028] When the concentration values for elements A, B, C, and D are determined, the washing execution unit 43 compares the concentration value of each element with the threshold value for each element stored in the storage unit 41. Then, if the concentration of any of the elements is below the threshold value (NO in Step 4), the washing execution unit 43 operates the washing liquid introduction unit 13 and the flow path switching valve 14, and washes the plasma ionization unit 10 and the mass analysis unit 30 using the standard washing liquid based on the information stored in the storage unit 41 (Step 5). On the other hand, if the concentration value of any of the elements exceeds the threshold value (YES in Step 4), the washing execution unit 43 operates the washing liquid introduction unit 13 and the flow path switching valve 14, washes the plasma ionization unit 10 and the mass analysis unit 30 using the standard washing liquid, and further washes the plasma ionization unit 10 and the mass analysis unit 30 using the additional washing liquid based on the information stored in the storage unit 41 (Step 6).

[0029] Specifically, for example, if the concentration value of element A exceeds the threshold value (100 ppm), after washing with the standard washing liquid, washing liquid a is further passed for 30 seconds. If the concentration values of both element A and element B exceed their threshold values (element A: 100 ppm, element B: 200 ppm), after washing with the standard washing liquid, washing liquid a is further passed for 30 seconds, and washing liquid b' is passed for 20 seconds. If the concentration values of elements for which the additional washing liquid is common exceed the threshold values, the additional washing liquid of the element with the longer supply time (or larger supply amount) is supplied. In this example, if the concentration values of both element A and element C exceed the threshold values, after executing the washing operation with the standard washing liquid, an additional washing operation is executed by further passing washing liquid a for 40 seconds.

[0030] When the washing operation by the washing execution unit 43 is completed, the quantitative analysis unit 42 checks whether the measurement of all samples has been completed. At this point, only the first sample has been measured, and unmeasured samples remain (NO in Step 7), so the process returns to Step 2 to measure the next sample. If the measurement of all samples has been completed (YES in Step 7), the series of measurement operations is terminated.

[0031] Since the inductively coupled plasma mass spectrometry apparatus has high sensitivity, it is suitable for detecting and quantifying trace elements, but on the other hand, carryover is likely to occur if elements contained in a previously measured sample remain. Therefore, to reliably prevent carryover, an excessive amount of washing liquid may be supplied by overestimating the amount of elements contained in the sample, or a washing liquid corresponding to an element may be supplied in consideration of the possibility that the element is contained, even if it is unlikely to be actually contained.

[0032] In contrast, in the inductively coupled plasma mass spectrometry apparatus 1 of the present embodiment, each time the elements to be measured contained in one sample are quantified, the concentration value of each element is determined (quantified). Then, if the concentration value (quantitative value) of none of the elements exceeds the threshold value, the inside of the apparatus is washed using only the standard washing liquid, and only when the concentration value (quantitative value) of any of the elements exceeds the threshold value, an additional washing is performed using a washing liquid of a type and amount corresponding to that element. Therefore, it is possible to wash the sample analysis apparatus using a washing liquid of an appropriate type and amount according to the amount of the analyte component contained in the sample analyzed immediately before, thereby preventing carryover. In the inductively coupled plasma mass spectrometry apparatus 1 of the present embodiment, an excessive amount of washing liquid is not supplied by overestimating the amount of elements contained in the sample, and a washing operation using a washing liquid for washing elements not contained in the sample is not performed, so the time required for continuously analyzing a plurality of samples can be shortened compared to the prior art.

[0033] In the above embodiment, the configuration is such that when the concentration of none of the elements to be measured exceeds the threshold value, the inside of the apparatus is washed using only the standard washing liquid, and when the concentration of any element exceeds the threshold value, washing is performed using an additional washing liquid. However, other configurations can also be adopted. Some examples of such configurations will be described below. The configurations described below can be executed by the washing setting change unit 44 changing the settings related to the washing of the apparatus in response to a predetermined input operation by the user.

[0034] In the above example, the threshold value is set as a concentration value (absolute value), but it may also be set as a ratio based on the maximum concentration in the calibration curve for each element. Specifically, for example, a common threshold value can be set for elements A, B, C, and D as 80% of the maximum concentration in the calibration curve. Alternatively, it can be configured such that for each of elements A, B, C, and D, threshold values are set individually as 80%, 70%, 75%, and 95% of the maximum concentration in the calibration curve. In this case, information on the washing liquid as shown in FIG. 4, for example, may be stored in the storage unit 41 in advance.

[0035] In all of the above examples, one type of washing liquid is associated with each element, but a plurality of washing liquids may be associated with one element. For example, a washing sequence may be set such that when the concentration value of element E exceeds a threshold value, in addition to washing with the standard washing liquid, the apparatus is washed by sequentially passing washing liquid A for 30 seconds, washing liquid B for 20 seconds, and pure water for 30 seconds, and when the concentration value of element F exceeds a threshold value, in addition to washing with the standard washing liquid, the apparatus is washed by sequentially passing washing liquid A for 40 seconds, washing liquid C for 30 seconds, and pure water for 30 seconds. By setting such a washing sequence for one or more elements that tend to remain in the flow paths, etc., within the apparatus, a washing operation using a plurality of washing liquids is executed, and such elements can be more reliably removed from the apparatus.

[0036] Alternatively, instead of the information of a standard washing liquid and an additional washing liquid, the washing liquid associated with each element may be supplied for a time (amount) corresponding to the quantitative value of the element. In that case, for example, for each element, information representing the relationship between the quantitative value of the element and the amount or supply time of the washing liquid (for example, a mathematical formula for finding the amount or supply time of the washing liquid with the quantitative value as a variable) may be stored in the storage unit 41, and the washing execution unit 43 may determine the amount or supply time of the washing liquid based on that mathematical formula. In this case, the inside of the apparatus can be washed with different amounts of washing liquid according to the concentration (quantitative value) of the element actually contained in the sample. When a common washing liquid is associated with a plurality of elements, the longest of the supply times of the washing liquid calculated from the mathematical formulas corresponding to each of the plurality of elements may be adopted.

[0037] The above embodiment is an example, and can be modified as appropriate in line with the spirit of the present invention.

[0038] Although the above embodiment is an inductively coupled plasma mass spectrometry apparatus, the same configuration as described above can also be adopted in an apparatus that detects atomic ions generated by an inductively coupled plasma ion source by another measurement method. Furthermore, the same configuration as described above can be adopted in various analysis apparatuses that use other ion sources, or in apparatuses that perform analysis without generating ions from the sample to be analyzed, and that perform analysis to quantify components contained in a sample for a plurality of samples. In particular, like the inductively coupled plasma mass spectrometry apparatus, the same configuration as described above can be suitably used in an atomic absorption spectrometry apparatus or the like that quantifies trace elements contained in a sample.

[0039] Further, in the above embodiment, only one threshold value is set for each element, but a plurality of threshold values may be set, and each time each threshold value is exceeded, a washing operation using the type and amount (or supply time) of a preset additional washing liquid may be executed.

[0040] [Aspects] It will be apparent to those skilled in the art that the exemplary embodiments described above are specific examples of the following aspects.

[0041] (Item 1) One aspect of the present invention is a sample analysis apparatus that quantifies an analyte component contained in a sample, the apparatus comprising: a storage unit in which information is stored that associates, for each of a plurality of known components that may be contained in a sample, an amount of the known component with a type and an amount of a washing liquid for removing the known component; a quantitative analysis unit that introduces a plurality of samples into the sample analysis apparatus in a predetermined order and quantifies an analyte component contained in each sample; a washing liquid introduction unit that introduces a washing liquid for washing the plurality of known components into the sample analysis apparatus; and a washing execution unit that, each time an analyte component contained in one sample is quantified by the quantitative analysis unit, determines a type and an amount of a washing liquid by collating information on the analyte component quantified by the quantitative analysis unit with the information stored in the storage unit, and operates the washing liquid introduction unit to perform a washing operation to remove the analyte component from the sample analysis apparatus.

[0042] In the sample analysis apparatus according to Item 1, information that associates, for each of a plurality of known components, an amount of the known component with a type and an amount of a washing liquid for removing the known component is stored in advance in a storage unit. Then, each time the quantitative analysis unit quantifies an analyte component contained in one sample, the washing execution unit determines a type and an amount of a washing liquid by collating information on the quantified analyte component with the information stored in the storage unit, operates the washing liquid introduction unit, and performs a washing operation to remove the analyte component from the sample analysis apparatus using the washing liquid of that type and amount. Therefore, it is possible to wash the sample analysis apparatus using a washing liquid of an appropriate type and amount according to the amount of the analyte component contained in the sample analyzed immediately before, thereby preventing carryover. In the sample analysis apparatus according to Item 1, an excessive amount of washing liquid is not supplied by overestimating the amount of elements contained in the sample, and a washing operation using a washing liquid for washing elements not contained in the sample is not performed, so the time required for continuously analyzing a plurality of samples can be shortened. Although the analyte component is often plural, the analyte component may be one.

[0043] (Item 2) The sample analysis apparatus according to Item 2 is the sample analysis apparatus according to Item 1, wherein the storage unit further stores information on a type and an amount of a standard washing liquid, information on a threshold value associated with each of the plurality of known components, and information on a type and an amount of an additional washing liquid to be used when the threshold value is exceeded, and the washing execution unit performs a washing operation using the standard washing liquid when a quantitative value of the analyte component does not exceed a threshold value associated with the analyte component, and executes a washing operation using the additional washing liquid associated with the analyte component in addition to the washing operation using the standard washing liquid when the quantitative value of the analyte component exceeds the threshold value associated with the analyte component.

[0044] In the sample analysis apparatus according to Item 2, for each of the analyte components, the apparatus can be washed with a washing liquid of an appropriate type and amount based on whether the quantitative value exceeds a threshold value. When the concentration values of components for which the additional washing liquid is common exceed the threshold values, the additional washing liquid of the component with the larger supply amount may be supplied.

[0045] (Item 3) The sample analysis apparatus according to Item 3 is the sample analysis apparatus according to Item 2, wherein the storage unit further stores information on a calibration curve and a maximum concentration for each of the plurality of known components, and the threshold value is set as a ratio with respect to the maximum concentration.

[0046] (Item 4) The sample analysis apparatus according to Item 4 is the sample analysis apparatus according to Item 3, wherein the ratio is set individually for the plurality of known components.

[0047] When a calibration curve is used for the quantification of a component contained in a sample, it is common to store information on a minimum concentration representing the quantification lower limit of the component and a maximum concentration expected to be contained in the sample, together with the calibration curve. In the sample analysis apparatus according to Item 3, a threshold value is set as a ratio with respect to the maximum concentration thus stored, and the apparatus can be washed with a washing liquid of an appropriate type and amount. At this time, the ratio with respect to the maximum concentration may be a common value for a plurality of known components, or may be set individually as in the sample analysis apparatus according to Item 4. In the latter case, the threshold value can be set more finely.

[0048] (Item 5) The sample analysis apparatus according to Item 5 is the sample analysis apparatus according to any one of Items 1 to 4, wherein the storage unit further stores information representing a relationship between a quantitative value of the plurality of known components and an amount of the washing liquid, and the washing execution unit executes a washing operation using an amount of washing liquid corresponding to the quantitative value of the analyte component.

[0049] In the sample analysis apparatus according to Item 5, for each of the known components, information representing the relationship between the quantitative value of the component and the amount or supply time of the washing liquid (for example, a mathematical formula for finding the amount or supply time of the washing liquid with the quantitative value as a variable) is stored in the storage unit, and the washing execution unit determines the amount or supply time of the washing liquid based on that mathematical formula. In the sample analysis apparatus according to Item 5, the inside of the apparatus can be washed with different amounts of washing liquid according to the concentration (quantitative value) of the element actually contained in the sample. When a common washing liquid is associated with a plurality of components, the longest of the supply times of the washing liquid calculated from the mathematical formulas corresponding to the plurality of components may be adopted.

[0050] (Item 6) The sample analysis apparatus according to Item 6 is the sample analysis apparatus according to any one of Items 1 to 5, wherein for at least one of the plurality of known components, a threshold value for the amount of the known component, and a washing sequence for executing a washing operation using a plurality of washing liquids in order when a quantitative value of the known component exceeds the threshold value, are set.

[0051] In the sample analysis apparatus according to Item 6, for example, for a component that tends to remain in the apparatus, by executing a washing operation using a plurality of washing liquids, that component can be more reliably removed from the apparatus.

[0052] (Item 7) The sample analysis apparatus according to Item 7 is the sample analysis apparatus according to any one of Items 1 to 5, wherein the quantitative analysis unit includes an inductively coupled plasma ion source that generates atomic ions from a component contained in the sample using inductively coupled plasma.

[0053] An analysis apparatus that detects a trace amount of a component contained in a sample with high sensitivity is more prone to carryover, and it is more often the case that an excessive amount of washing liquid is supplied by overestimating the amount of elements contained in the sample, or a washing operation using a washing liquid for washing elements not contained in the sample is performed. Therefore, the configuration of the sample analysis apparatus according to any one of Items 1 to 6 can be suitably used. As one such sample analysis apparatus, an analysis apparatus including an inductively coupled plasma ion source as described in Item 7 can be mentioned.REFERENCE SIGNS LIST

[0054] 1... Inductively coupled plasma mass spectrometry apparatus 10... Plasma ionization unit 11... Autosampler 12... Nebulizer gas supply source 13... Washing liquid introduction unit 14... Flow path switching valve 15... Plasma gas supply source 20... Plasma torch 21... Argon plasma 30... Mass analysis unit 31... First vacuum chamber 32... Second vacuum chamber 321... Quadrupole mass filter 322... Detector 40... Control / processing unit 41... Storage unit 42... Quantitative analysis unit 43... Washing execution unit 44... Washing setting change unit 60... Input unit 70... Display unit

Examples

Embodiment Construction

[0011]An inductively coupled plasma mass spectrometry apparatus (ICP-MS), which is an embodiment of the sample analysis apparatus according to the present invention, will be described below with reference to the drawings.

[0012]FIG. 1 is a schematic configuration diagram of an inductively coupled plasma mass spectrometry apparatus 1 of the present embodiment. This inductively coupled plasma mass spectrometry apparatus 1 includes a plasma ionization unit 10, a mass analysis unit 30, and a control / processing unit 40.

[0013]The plasma ionization unit 10 has a plasma torch 20 in which a sample flow tube through which a liquid sample nebulized by a nebulizer gas flows, a plasma gas tube formed on the outer periphery of the sample flow tube, and a cooling gas tube formed on its further outer periphery are formed. Connected to the sample flow tube are an autosampler 11 that introduces a liquid sample, a nebulizer gas supply source 12 that supplies a nebulizer gas to nebulize the liquid sampl...

Claims

1. A sample analysis apparatus that quantifies an analyte component contained in a sample, the apparatus comprising: a storage unit in which information is stored that associates, for each of a plurality of known components that may be contained in a sample, an amount of the known component with a type and an amount of a washing liquid for removing the known component; a quantitative analysis unit that introduces a plurality of samples into the sample analysis apparatus in a predetermined order and quantifies an analyte component contained in each sample; a washing liquid introduction unit that introduces a washing liquid for washing the plurality of known components into the sample analysis apparatus; and a washing execution unit that, each time an analyte component contained in one sample is quantified by the quantitative analysis unit, determines a type and an amount of a washing liquid by collating information on the analyte component quantified by the quantitative analysis unit with the information stored in the storage unit, and operates the washing liquid introduction unit to perform a washing operation to remove the analyte component from the sample analysis apparatus.

2. The sample analysis apparatus according to claim 1, wherein the storage unit further stores information on a type and an amount of a standard washing liquid, information on a threshold value associated with each of the plurality of known components, and information on a type and an amount of an additional washing liquid to be used when the threshold value is exceeded, and the washing execution unit performs a washing operation using the standard washing liquid when a quantitative value of the analyte component does not exceed a threshold value associated with the analyte component, and executes a washing operation using the additional washing liquid associated with the analyte component in addition to the washing operation using the standard washing liquid when the quantitative value of the analyte component exceeds the threshold value associated with the analyte component.

3. The sample analysis apparatus according to claim 2, wherein the storage unit further stores information on a calibration curve and a maximum concentration for each of the plurality of known components, and the threshold value is set as a ratio with respect to the maximum concentration.

4. The sample analysis apparatus according to claim 3, wherein the ratio is set individually for the plurality of known components.

5. The sample analysis apparatus according to claim 1, wherein the storage unit further stores information representing a relationship between a quantitative value of the plurality of known components and an amount of the washing liquid, and the washing execution unit executes a washing operation using an amount of washing liquid corresponding to the quantitative value of the analyte component.

6. The sample analysis apparatus according to claim 1, wherein for at least one of the plurality of known components, a threshold value for the amount of the known component, and a washing sequence for executing a washing operation using a plurality of washing liquids in order when a quantitative value of the known component exceeds the threshold value, are set.

7. The sample analysis apparatus according to claim 1, wherein the quantitative analysis unit includes an inductively coupled plasma ion source that generates atomic ions from a component contained in the sample using inductively coupled plasma.

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