Mass analysis method and mass analysis device

Abstract

One aspect of a mass analysis method according to the present invention is a mass analysis method using a mass analysis device capable of performing DDA-based MS / MS analysis, the mass analysis method comprising: detection steps (S1 to S5) for detecting m / z values of peaks continuously observed for a predetermined period of time on the basis of a mass spectrum obtained by repeatedly performing full-spectrum scanning measurement; a registration step (S6) in which the detected m / z value or an m / z range including the m / z value is registered in an excluded ion list; a precursor selection step (S8) for excluding at least the m / z value or the m / z range registered in the excluded ion list from the precursor selection target in the mass spectrum after the mass spectrum is obtained by full-spectrum scanning measurement, and extracting ions that meet a prescribed precursor selection condition; and a measurement step (S9) of performing MS / MS analysis using the extracted ions as precursor ions following the full-spectrum scanning measurement in the precursor selection step.

Description

TECHNICAL FIELD

[0001] The present application relates to a mass analysis method and a mass analysis device, and more particularly, to a mass analysis method using MS / MS analysis, and a mass analysis device capable of MS / MS analysis. BACKGROUND

[0002] In recent years, tandem mass analysis devices capable of MS / MS analysis, such as triple quadrupole type mass analysis devices and quadrupole-time of flight type mass analysis devices, are widely used for identification, quantification, or structural analysis of compounds in a complex sample containing a variety of compounds. In a liquid chromatograph mass analysis device (LC-MS) or a gas chromatograph mass analysis device (GC-MS) using a tandem mass analysis device as a detector, one of the methods of performing MS / MS analysis as a mass analysis device, data dependent acquisition (DDA: Data Dependent Acquisition, or Data Dependent Analysis) is well known (see Patent Documents 1 and 2).

[0003] In DDA, first, a mass spectrum is acquired by a normal scan (hereinafter sometimes referred to as "full scan") measurement without dissociating ions, and a peak of a specific mass-to-charge ratio (strictly speaking, m / z with an italic mark, but in this specification, "m / z" or "mass-to-charge ratio" is written) is selected from the signal intensity or the like of the peak observed in the mass spectrum. Then, MS / MS analysis (product ion scan measurement) is performed with ions having an m / z value corresponding to the selected peak as precursor ions after the full scan, and an MS / MS spectrum in which a variety of product ions can be observed is acquired.

[0004] DDA is also called a shotgun method, and it is expected that product ion information corresponding to various types of compounds contained in a sample can be collected as comprehensively as possible. However, in LC-MS or GC-MS, since the same compound is continuously introduced into the mass analysis device over time, if only the process of selecting a peak with a large signal intensity is performed in the mass spectrum, there is a concern that product ion information derived from the same compound will be continuously collected. To avoid this, in the conventional device, a function of excluding the m / z value of the peak temporarily selected as a precursor ion from the selection target of the precursor ion within a prescribed effective period (hereinafter referred to as "selected ion automatic removal function") is adopted. The effective period is usually set according to the time during which one component is continuously eluted from the LC (or GC) column, and is determined to be 10 seconds or the like, for example.

[0005] Furthermore, Patent Document 3 describes a function that allows a known inclusion, interfering component, and known component that does not need to be analyzed contained in a sample to be excluded from the selection of precursor ions by pre-registering these ions in an exclusion ion list (hereinafter referred to as "exclusion ion pre-registration function").

[0006] Existing technical documents Patent documents Patent Document 1: International Publication No. 2017 / 158770 Patent Document 2: Japanese Patent Application Publication No. 2012-2544 Patent Document 3: Japanese Patent Application Publication No. 2012-225862 Summary of the Invention The technical problem that the invention aims to solve The aforementioned pre-registration function for excluded ions can only exclude ions with specific m / z values ​​or within a specific m / z range that have been pre-defined by the user from the precursor selection list. Therefore, if, for example, unexpected or unforeseen inclusions are present in the mobile phase of the LC, ions originating from these inclusions cannot be removed from the precursor selection list. As a result, repeated MS / MS analyses for these undesirable ions will be necessary, raising concerns about reduced opportunities to obtain product ion information from components the user wishes to identify.

[0007] While the automatic ion removal function described above can exclude ions from the precursor selection, the effective period of this function is usually short. Therefore, after this effective period ends, MS / MS analysis using ions from unexpected inclusions as precursor ions will be performed again. This prevents users from comprehensively collecting product ion information from the components they wish to identify.

[0008] The present invention is proposed to solve the above-mentioned technical problems. Its main purpose is to provide a quality analysis method and a quality analysis device that can avoid performing MS / MS analysis on ions from unwanted components that are unknown to be detected in advance, and can efficiently and comprehensively collect product ion information from target components.

[0009] Solution to the above technical problems One aspect of the quality analysis method involved in this invention is a quality analysis method utilizing a quality analysis device capable of performing MS / MS analysis based on data dependency acquisition (DDA), comprising: A detection step that detects peaks with continuously observable m / z values ​​over a specified period, based on mass spectra obtained through repeated full-spectrum scanning measurements; The registration step involves registering the m / z value of the peak detected in the detection step, or the m / z range containing that m / z value, to the exclusion ion list. After obtaining a mass spectrometer through full-spectrum scanning, at least the m / z values ​​or m / z ranges registered in the excluded ion list are excluded from the precursor selection targets, and a precursor selection step is taken to extract ions that meet the specified precursor selection conditions. Following the full-spectrum scan measurement in the precursor selection step, an MS / MS analysis step is performed using the ions extracted in the precursor selection step as precursor ions.

[0010] Furthermore, one aspect of the quality analysis apparatus according to the present invention is a quality analysis apparatus capable of performing MS / MS analysis based on data dependency acquisition (DDA), comprising: A specific peak detection unit is used to detect peaks with m / z values ​​that are continuously observed over a specified period, based on mass spectra obtained through repeated full-spectrum scanning measurements. The m / z value of the peak detected by the specific peak detection unit, or the m / z range containing that m / z value, is registered in the excluded ion registration unit of the excluded ion list; A full-spectrum scan measurement is performed, and based on the mass spectra obtained by the measurement, a measurement unit is then performed to perform MS / MS analysis using ions extracted in the precursor selection unit (described later) as precursor ions. In the mass spectra obtained by the full-spectrum scan measurement performed in the measurement unit, at least the m / z values ​​or m / z ranges registered in the excluded ion list are excluded from the precursor selection targets, and the precursor selection unit extracts ions that meet the prescribed precursor selection conditions.

[0011] Here, the "peak with an m / z value that is continuously observed within a specified period" detected in the detection step and the specific peak detection unit can be considered as having substantially the same m / z value. Therefore, even if peaks with the same true m / z value have deviated or changed their apparent m / z value due to limitations in the device's performance, changes in the measurement environment or measurement conditions, these deviated or changed m / z values ​​are also considered to be the same.

[0012] Furthermore, the full-spectrum scanning measurement that obtains mass spectra used in the detection step and the specific peak detection unit can be the same measurement as the full-spectrum scanning measurement that obtains mass spectra used for ion extraction in the precursor selection step and the precursor selection unit, or they can be measurements performed at different times.

[0013] Invention Effects According to the above-described scheme of the quality analysis method and apparatus of the present invention, it is possible to avoid selecting ions of components that may be observed throughout the measurement time, such as inclusions mixed in the mobile phase used for LC in LC-MS, as precursor ions for MS / MS analysis. Therefore, it is possible to collect product ion information corresponding to the components contained in the sample that the user originally intended to target more efficiently and comprehensively. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the configuration of an LC-MS according to an embodiment of the present invention.

[0015] Figure 2 This is a flowchart illustrating an example of the execution steps for analysis in DDA mode in the LC-MS of this embodiment.

[0016] Figure 3 This is a schematic diagram showing the correspondence between measurement time and processing in the LC-MS of this embodiment. Detailed Implementation

[0017] The mass analysis apparatus involved in this invention only needs to be capable of performing MS / MS analysis. Therefore, it can include, for example, a triple quadrupole mass analysis apparatus, a quadrupole-time-of-flight mass analysis apparatus (hereinafter referred to as "Q-TOFMS"), an ion trap time-of-flight mass analysis apparatus, an ion trap mass analysis apparatus, etc. Typically, the mass analysis apparatus involved in this invention can be combined with LC or GC to form LC-MS or GC-MS.

[0018] Hereinafter, an embodiment of the LC-MS using the quality analysis apparatus according to the present invention will be described with reference to the accompanying drawings.

[0019] [The Composition of LC-MS] Figure 1 This is a schematic diagram of the LC-MS configuration in this embodiment.

[0020] This LC-MS has a liquid chromatography (LC) section 1 and a mass analysis (MS) section 2 as measurement units, and also has a control / processing section 3, a power supply section 4, an input section 5 and a display section 6.

[0021] The LC section 1 includes a mobile phase container 11, a delivery pump 12, a syringe 13, and a chromatographic column 14.

[0022] MS section 2 is a Q-TOFMS, which includes an ionization chamber 21 with an atmosphere of approximately atmospheric pressure and a vacuum chamber 20 divided into four regions. A first intermediate vacuum chamber 22, a second intermediate vacuum chamber 23, a first high vacuum chamber 24, and a second high vacuum chamber 25 are provided in the vacuum chamber 20. Each chamber is sequentially evacuated by a vacuum pump (not shown) to increase the vacuum level sequentially.

[0023] In the ionization chamber 21, an electrospray ionization (ESI) probe 211 is provided, which supplies liquid sample (eluent) from the LC section 1. The ionization chamber 21 is connected to the first intermediate vacuum chamber 22 via a thin-diameter desolvation tube 212. The first intermediate vacuum chamber 22 and the second intermediate vacuum chamber 23 are connected via an orifice formed at the top of the conical orifice 222. Ion guides 221 and 231 are respectively provided in the first intermediate vacuum chamber 22 and the second intermediate vacuum chamber 23. In the first high vacuum chamber 24, along the ion optical axis C1, a quadrupole mass filter 241 and a collision cell 242 with an ion guide 243 inside are provided. Multiple electrodes arranged across the first high vacuum chamber 24 and the second high vacuum chamber 25 constitute an ion guide 244. Inside the second high vacuum chamber 25, there is an orthogonal acceleration time-of-flight mass separator with an orthogonal acceleration section 251 and an ion flight section 252 including a reflector 253, as well as an ion detector 255.

[0024] The power supply unit 4 is a component that drives the MS unit 2 by applying predetermined voltages to the electrodes and other components contained in the MS unit 2 under the control of the control / processing unit 3. The control / processing unit 3 is responsible for the operation control of the LC unit 1 and the MS unit 2 and for processing the data obtained in the MS unit 2. As a functional module, it includes a measurement condition setting unit 31, a measurement control unit 32, a data collection unit 33, a mass spectrometry generation unit 34, a precursor selection unit 35, an excluded ion recognition unit 36, and an excluded ion list storage unit 37.

[0025] Generally, the control / processing unit 3 is a computer such as a personal computer or workstation. The aforementioned functional modules are realized by executing one or more dedicated software programs (computer programs) installed on such a computer. Such computer programs can be stored on computer-readable, non-transitory recording media such as CD-ROMs, DVD-ROMs, memory cards, or USB storage devices (dongles) and provided to the user. Alternatively, they can be provided to the user via data transmission through communication lines such as the Internet. Alternatively, they can be pre-installed on the computer as part of the system when the user purchases the system.

[0026] [A general overview of LC-MS measurement procedures] In the LC section 1, under the control of the measurement control unit 32, the delivery pump 12 draws the mobile phase from the mobile phase container 11 and delivers the mobile phase into the chromatographic column 14 at a predetermined flow rate (flow rate). The syringe 13, under the instruction of the measurement control unit 32, injects the liquid sample into the mobile phase at a predetermined time. The liquid sample is delivered into the chromatographic column 14 along with the flow of the mobile phase, and the various components contained in the liquid sample are separated over time as they pass through the chromatographic column 14, eluting from the outlet of the chromatographic column 14. Thus, the eluent, whose composition changes over time, is introduced into the ESI probe 211 of the MS section 2.

[0027] The measurement control unit 32 can control the power supply unit 4, and by controlling the various voltages supplied to the MS unit 2, the MS unit 2 can perform analysis of the sequentially supplied eluent. In the MS unit 2, it is possible to selectively perform conventional mass analysis (MS analysis) without ion dissociation and MS / MS analysis that dissociates ions through collision-induced dissociation (CID).

[0028] ESI probe 211 sprays the supplied eluent into ionization chamber 21 in the form of charged droplets. The charged droplets are atomized upon contact with the surrounding residual gas, and during solvent vaporization within the droplets, the compounds become gaseous ions. The generated ions are then fed into the first intermediate vacuum chamber 22 via desolvation tube 212, and sequentially pass through ion guide 221, cone-shaped body 222, and ion guide 231 before being introduced into quadrupole mass filter 241. In the case of MS analysis, the ions pass almost directly through quadrupole mass filter 241 and collision cell 242, and are then transported to orthogonal acceleration section 251 via ion guide 244.

[0029] On the other hand, in the case of MS / MS analysis, a predetermined voltage is applied to each of the multiple rod electrodes constituting the quadrupole mass filter 241. Ions having a specific m / z corresponding to this voltage, or an m / z within a specific m / z range, selectively pass through the quadrupole mass filter 241 as precursor ions. In the collision cell 242, a collision gas such as Ar is introduced. The precursor ions contact the collision gas and dissociate by CID to generate various product ions. The generated product ions are then transported to the orthogonal acceleration unit 251 via the ion guide 244.

[0030] Most of the ions arriving at the orthogonal acceleration section 251 are accelerated approximately simultaneously in a direction approximately orthogonal to its incident direction. The accelerated ions travel in the ion flight section 252 at velocities corresponding to their respective m / z values. Figure 1The ions, as shown by the dashed line C2, undergo a reversal flight and arrive at the ion detector 255. Ions departing from the orthogonal acceleration unit 251 approximately simultaneously arrive at the ion detector 255 in ascending order of m / z and are detected. The ion detector 255 outputs detection data (ion intensity data) corresponding to the number of ions to the control / processing unit 3. In the control / processing unit 3, the data collection unit 33 stores the received data. The mass spectrometry generation unit 34 generates a time-of-flight spectrum based on the collected data, and generates an MS spectrum or MS / MS spectrum by converting the time of flight to m / z.

[0031] Furthermore, the SN ratio and sensitivity of the data obtained through the cycle of ion emission from the orthogonal acceleration unit 251 → ion flight in the ion flight unit 252 → ion detection in the ion detector 255 are not sufficiently high in most cases. Therefore, the cycle of measurement corresponding to the same m / z range is usually repeated multiple times, and mass spectrometry or MS / MS spectra are generated by integrating the data obtained from these multiple cycles.

[0032] [Characteristic DDA Pattern Action Description] Next, the operation of the characteristic DDA mode implemented in MS section 2 will be explained. Figure 2 This is a flowchart outlining the execution steps of the actions from the start time of measurement to the end time. Figure 3 A diagram is provided to illustrate the relationship between measurement time and processing content in this action in a general sense.

[0033] Before analysis, the user inputs the measurement conditions for DDA mode via input unit 5, or changes the preset default values ​​if necessary. Measurement condition setting unit 31 accepts the input and changes of measurement conditions and saves the measurement conditions. These measurement conditions include precursor selection conditions and automatic ion exclusion detection conditions, which will be described later.

[0034] Precursor selection conditions are used to extract more than one ion species as precursor ions in mass spectrometry. These conditions can include selection orders such as ordering by signal intensity from high to low, or selecting peaks whose signal intensity falls within a specified range and is ordered from high to low, as well as the number of peaks selected. Furthermore, it is possible to simultaneously set conditions for preferred ions and excluded ions during precursor selection. For example, even for compounds with low signal intensity but significant importance, the m / z value corresponding to that compound can be designated as the preferred ion. Conversely, if it is desired to exclude m / z values ​​corresponding to specific known compounds from the selection pool, the m / z values ​​corresponding to such compounds can be designated as excluded ions. Moreover, these precursor selection conditions can employ various previously known conditions.

[0035] On the other hand, automatic ion exclusion detection conditions are used to automatically extract ions to be excluded from the precursor selection based on measurement results. Specifically, these conditions may include a detection period (detection start time and detection end time, etc.) for detecting ions to be excluded, and an effective exclusion period (exclusion start time and exclusion end time, etc.) during which exclusion continues after the ions are registered in the exclusion ion list. Furthermore, conditions may also include the signal intensity and m / z range at the peak of the ions to be excluded. In the following example, the detection period for excluded ions is from the measurement start time (t=0) to the elapsed time t=t1. And the effective exclusion period is from the time the ions are registered in the exclusion ion list to the measurement end time (t=t2).

[0036] When the measurement begins according to the user's instructions, the syringe 13 in the LC unit 1 injects the liquid sample into the mobile phase. The injected liquid sample is introduced into the chromatographic column 14, but it takes a certain amount of time for the various components contained in the liquid sample to elute from the outlet of the chromatographic column 14. Therefore, for a period of time from the injection time of the liquid sample, i.e., the measurement start time, the eluent introduced into the ESI probe 211 does not actually contain the sample components, but only the mobile phase.

[0037] Under the control of the measurement control unit 32, MS unit 2 can repeatedly perform MS analysis covering a specified m / z range at predetermined time intervals, i.e., full-spectrum scanning measurement. Since TOFMS is used in MS unit 2 here, it is not actually a scanning measurement, but for ease of explanation, it is referred to as a full-spectrum scanning measurement. Furthermore, in this example, MS / MS analysis is not performed immediately after the full-spectrum scanning measurement until t=t1 is reached; however, as will be described later, DDA-based MS / MS analysis can also be performed from the beginning of the measurement.

[0038] When the first full-spectrum scan measurement is performed, the data collection unit 33 receives signal intensity data from the MS unit 2 during the full-spectrum scan measurement, and the mass spectrometry generation unit 34 generates a mass spectrum covering a specified m / z range (step S1). After a mass spectrum is generated, the excluded ion recognition unit 36 ​​temporarily stores the m / z values ​​of the peaks observed in the mass spectrum (step S2). As an automatic excluded ion detection condition, if a threshold for the signal intensity of a peak is specified, only peaks with signal intensities above the specified threshold can be selected, instead of all peaks on the mass spectrum, and the m / z value of that peak can be temporarily stored.

[0039] If a second full-spectrum scan measurement is performed in MS unit 2 and a mass spectrum is generated by mass spectrometry generation unit 34 (step S3), then the exclusion ion recognition unit 36 ​​will only save the m / z values ​​of the peaks observed in the new mass spectrum from the m / z values ​​temporarily saved in step S2, and delete the other m / z values ​​(step S4). Thus, only the m / z values ​​of the peaks observed in both of the mass spectra obtained from the two consecutive full-spectrum scan measurements are temporarily saved.

[0040] Next, the excluded ion recognition unit 36 ​​determines whether the time elapsed from the measurement start time (t=0) has reached t1 (step S5) as defined by the automatic excluded ion detection conditions. If not, it returns to step S3. Therefore, the processing of steps S3 to S5 is repeated within a pre-defined period as the excluded ion detection period. Thus, at the time point when the time elapsed from the measurement start time reaches t1, i.e., the time point determined as "yes" in step S5, the m / z values ​​of ions continuously observed in the mass spectrometer during the excluded ion detection period are stored in the excluded ion recognition unit 36.

[0041] As described above, the components contained in the liquid sample injected by syringe 13 have not yet been introduced into the MS unit 2 shortly after the start of the measurement. Therefore, the components continuously observed during the ion exclusion detection period can be inferred to be components (inclusions) contained in the flowing mobile phase since the initial start of the measurement. This component is obviously not the component that the user expects as the object of observation. Therefore, when the determination is "yes" in step S5, the ion exclusion identification unit 36 ​​registers the m / z value temporarily stored at that time point into the ion exclusion list prepared in the ion exclusion list storage unit 37 (step S6). That is, the m / z value corresponding to the component that the user does not expect is automatically registered into the ion exclusion list.

[0042] Subsequently, a full-spectrum scan measurement is performed in MS unit 2, and mass spectrometry generation unit 34 generates a mass spectrum (step S7). Precursor selection unit 35 removes m / z values ​​already registered in the exclusion ion list from the peaks detected in the mass spectrum and extracts peaks that meet the preset precursor selection conditions (step S8). Therefore, as described above, even if an ion corresponding to a component in the mobile phase that is undesirable to the user is observed on the mass spectrum, that ion will not be selected as a precursor ion.

[0043] Now, the precursor selection condition is set to select a peak in descending order of signal intensity. In this case, in step S8 above, from the peaks detected in the mass spectrometer, peaks with m / z values ​​registered in the exclusion ion list are excluded, and the ion corresponding to the peak with the highest signal intensity is selected as the precursor ion from the remaining peaks.

[0044] Subsequently, the measurement control unit 32 receives the identified precursor ion information and, via the power supply unit 4, controls the MS unit 2 to perform MS / MS analysis targeting that precursor ion. That is, in step S8, if a peak meeting the precursor selection criteria is found, MS / MS analysis is performed after a full-spectrum scan measurement. The data collection unit 33 receives the detection data obtained from the MS unit 2 through MS / MS analysis, and the mass spectrometry generation unit 34 generates the MS / MS spectrum (step S9).

[0045] Subsequently, the measurement control unit 32 determines whether the measurement end time t2, one of the pre-set measurement conditions, has elapsed (step S10). If it has not elapsed, it returns to step S7. Therefore, as Figure 3 As shown, during the period from the measurement time t1 to the measurement end time t2, steps S7 to S10 are repeated. Under the condition of excluding precursor selection based on m / z values ​​already registered in the exclusion ion list, the selected precursor ion is used as the target, and DDA-based MS / MS analysis is repeated. Furthermore, although in Figure 2 Not shown in the text, but in step S8, if there are no peaks that meet the precursor selection criteria, then because there are no precursor ions for which MS / MS analysis should be performed, the processing of step S9 is skipped and the process proceeds to step S10. If the measurement end time t2 has not yet passed, the process returns to step S7 and waits for the next full-spectrum scan measurement to be performed.

[0046] As described above, when an inclusion is present in the mobile phase, although the signal intensity may fluctuate, ions originating from that inclusion should be observed almost continuously from the start to the end of the measurement. In contrast, in the LC-MS of the above embodiment, the m / z values ​​of ions originating from such inclusions can be automatically added to an exclusion ion list, and MS / MS analysis using ions from that inclusion as precursor ions can be avoided before the end of the measurement. This increases the likelihood of obtaining product ion information corresponding to components other than the inclusion that the user would normally want to observe, thus effectively enabling efficient and comprehensive collection of product ion information.

[0047] [Variation Example] In the above explanation, when confirming the existence of a peak with the same m / z value as the one temporarily stored in step S4, it is preferable not to use completely identical m / z values, but rather to determine a predetermined allowable width. If a peak falls within the m / z range determined by this allowable width, it is judged to be of the same ion species. Thus, even if there are errors (resolution) or variations in the measured m / z value, the same ion species can be detected.

[0048] Furthermore, in the above description, the period from the execution of step S1 to the determination of "yes" in step S5, that is, from the start time of the measurement to the elapsed time t1, does not immediately follow the full-spectrum scan measurement with MS / MS analysis. However, it is possible to perform DDA-based MS / MS analysis in the same manner as after step S7.

[0049] In addition, Figure 2 In the example shown, although only one MS / MS analysis was performed after the full-spectrum scan measurement, if there is sufficient time, multiple MS / MS analyses can be performed for different precursor ions after the full-spectrum scan measurement.

[0050] In addition, Figure 2 In the example shown, ions with m / z values ​​that are automatically registered in the exclusion ion list are continuously excluded from the precursor ion selection until the measurement end time t2. However, a function can also be added to automatically delete the registered m / z values ​​from the exclusion ion list when the specified release conditions are met during the measurement.

[0051] Specifically, for example, after registering one or more m / z values ​​to the excluded ion list in step S6, it is also possible to continuously determine whether the peak of the m / z value is continuously observed in the mass spectrum obtained by full-spectrum scanning measurement, and if it is not continuously observed within a specified time, the m / z value is deleted from the excluded ion list.

[0052] For example, during gradient elution in LC section 1, the mixing ratio of the two different mobile phases supplied to column 14 changes over time. In this case, if an inclusion is introduced into one of the mobile phases, it is possible that ions originating from that inclusion may be observed for a short period starting from the measurement start time, but after a certain time point, those ions will essentially no longer be observed. In this situation, according to the method described above, the m / z value of the ion originating from that inclusion can be removed from the exclusion ion list during the measurement. Therefore, when an ion originating from another (or the same) component with the same m / z value as the ion originating from that inclusion is detected on the mass spectrometer, this ion can be used as a precursor ion for MS / MS analysis, thereby facilitating the comprehensive collection of product ion information.

[0053] Furthermore, in the above example, only the period from the start of the measurement to the elapsed time t1 is considered the detection period for continuously observed ions. However, this period can be determined as any period based on the user's automatic exclusion ion detection settings. Therefore, it is also possible to monitor the m / z values ​​observed in the mass spectrum obtained through full-spectrum scanning measurement throughout the entire measurement period from the start of the measurement to the end of the measurement, and if a m / z value for a specified period is continuously observed at any time point during the measurement, that m / z value is registered in the exclusion ion list.

[0054] Furthermore, even if there are m / z shifts or variations due to limitations in device performance such as m / z resolution, as described above, the allowable m / z width for detection can be used to treat them as the same m / z value. However, in LC-MS or GC-MS, due to various factors such as changes in device status or external environment, the m / z value of the same ion species in the mass spectrum may gradually shift and drift over time. When this drift occurs, even if the actual m / z value is the same, the apparent m / z value in the mass spectrum may exceed the allowable width. Therefore, in the case of the aforementioned time-dependent drift of m / z values, the following configuration can be adopted, and this configuration can be used for processing.

[0055] That is, a reference substance with a known m / z value is continuously added to the eluent flowing out of the chromatographic column 14. The peak of the reference substance is monitored on the mass spectrum obtained by full-spectrum scanning, thereby real-time monitoring of the m / z value shift over time from the start of the measurement. Then, based on this m / z value shift over time, the m / z values ​​and m / z ranges of ions classified as the same type are staggered. Thus, even if there is an m / z value drift that cannot be covered by the normally fixed allowable m / z width, it is possible to accurately detect cases where the same type of ion is continuously observed, and to register such ions in the exclusion ion list.

[0056] As described above, in the LC-MS of the above embodiments or their variations, it is possible to avoid selecting ions of components that are undesirable to the user, such as unknown inclusions mixed in the mobile phase, as precursor ions for MS / MS analysis. Therefore, product ion information corresponding to the original target component can be collected efficiently and comprehensively.

[0057] Furthermore, the method for selecting precursors described in the above embodiments can be combined with existing known or used methods, as long as it does not contradict them.

[0058] For example, it is known that a method exists for pre-setting m / z values ​​(and their permissible values) to be excluded from precursor selection and an exclusion time range, and for excluding ions with the set m / z values ​​within the set time range; the method described above can be used in conjunction with this method. Furthermore, for example, even if an m / z value or m / z range is already registered in the list of excluded ions as described above, a m / z value (and its permissible value) that has been pre-determined as a preferred precursor ion can be selected as a precursor ion without exclusion.

[0059] Furthermore, while the DDA mode operation was repeated in the above description of the implementation method, there are also cases where another data acquisition method, namely Data Independent Acquisition (DIA), is used alternately with DDA, or where DDA is implemented after multiple DIA operations. Even in these cases, it is obvious that the aforementioned effects can be achieved by employing the aforementioned precursor selection method in DDA.

[0060] Furthermore, the above embodiments apply the mass analysis apparatus of this invention to Q-TOFMS. However, as mentioned above, this invention is applicable to various other mass analysis apparatuses capable of performing MS / MS analysis, such as triple quadrupole mass analysis apparatuses, ion trap time-of-flight mass analysis apparatuses, and ion trap mass analysis apparatuses. Moreover, the ionization method in the ion source is not limited to ESI; obviously, suitable ionization methods such as APCI, PESI, and DART can also be used.

[0061] Furthermore, the above embodiments are merely examples of the present invention, and any modifications, alterations, or additions that are appropriate within the scope of the present invention are obviously included within the scope of the claims of this application.

[0062] [Various options] The exemplary embodiments described above are specific examples of the following solutions, which will be obvious to those skilled in the art.

[0063] (Item 1) One aspect of the quality analysis method involved in this invention is a quality analysis method utilizing a quality analysis device capable of performing MS / MS analysis based on data dependency acquisition, comprising: A detection step that detects peaks with continuously observable m / z values ​​over a specified period, based on mass spectra obtained through repeated full-spectrum scanning measurements; The registration step involves registering the m / z value of the peak detected in the detection step, or the m / z range containing that m / z value, to the exclusion ion list. After obtaining a mass spectrometer through full-spectrum scanning, at least the m / z values ​​or m / z ranges registered in the excluded ion list are excluded from the precursor selection targets, and a precursor selection step is taken to extract ions that meet the specified precursor selection conditions. Following the full-spectrum scan measurement in the precursor selection step, an MS / MS analysis step is performed using the ions extracted in the precursor selection step as precursor ions.

[0064] (Item 6) One aspect of the quality analysis apparatus according to the present invention is a quality analysis apparatus capable of performing MS / MS analysis based on data dependency acquisition, comprising: A specific peak detection unit is used to detect peaks with m / z values ​​that are continuously observed over a specified period, based on mass spectra obtained through repeated full-spectrum scanning measurements. The m / z value or the m / z range containing the m / z value detected by the specific peak detection unit is registered in the excluded ion registration unit of the excluded ion list; A full-spectrum scan measurement is performed, and based on the mass spectra obtained by the measurement, an MS / MS analysis is performed using ions extracted in the precursor selection section described later as precursor ions. In the mass spectra obtained by the full-spectrum scan measurement performed in the measurement unit, at least the m / z values ​​or m / z ranges registered in the excluded ion list are excluded from the precursor selection targets, and the precursor selection unit extracts ions that meet the prescribed precursor selection conditions.

[0065] According to the mass analysis method described in item 1 and the mass analysis apparatus described in item 6, it is possible to avoid selecting ions of components that are likely to be observed throughout the measurement time, such as inclusions mixed in the mobile phase used for LC in LC-MS, as precursor ions for MS / MS analysis. Therefore, it is possible to collect product ion information corresponding to the components contained in the sample that the user originally intended to obtain more efficiently and comprehensively.

[0066] (Item 2) In the quality analysis method described in Item 1, it can be configured to further include: a deletion step that removes the m / z value or m / z range registered in the exclusion ion list in the registration step from the exclusion ion list when a specified release condition is met.

[0067] (Item 7) Furthermore, in the mass analysis apparatus described in Item 6, it can be configured such that the excluded ion registration unit deletes the m / z value or m / z range registered in the excluded ion list from the excluded ion list when the prescribed release conditions are met.

[0068] According to the mass analysis method described in item 2 and the mass analysis apparatus described in item 7, when a sample containing an inclusion having an m / z value temporarily registered in an exclusion ion list and other compounds having the same m / z value are introduced, the possibility of collecting product ion information from other compounds in the sample can be increased.

[0069] (Item 3) In the quality analysis method described in Item 1 or Item 2, it can be configured as a quality analysis method using a quality analysis device with a chromatograph connected to the front end, wherein in the detection step, during the period from when the components of the sample introduced into the chromatograph flow out of the chromatograph column and are introduced into the quality analysis device, a peak having an m / z value that is continuously observed within a specified period is detected.

[0070] (Item 8) In the quality analysis apparatus described in Item 6 or Item 7, it can be configured to be a quality analysis apparatus with a chromatograph connected as a pre-stage, wherein the specific peak detection unit detects a peak having an m / z value that is continuously observed within a specified period during the period from when the component of the sample introduced into the chromatograph flows out of the chromatograph column and is introduced into the quality analysis apparatus.

[0071] According to the quality analysis method described in item 3 and the quality analysis apparatus described in item 8, even if the mobile phase of the chromatograph contains inclusions that the user did not expect, it is possible to avoid repeating MS / MS analysis of the inclusions and to increase the likelihood of collecting product ion information from the component that was originally targeted.

[0072] (Item 4) In any of the mass analysis methods in items 1 to 3, it can be set such that, in the detection step, peaks that enter the specified allowable m / z width on the mass spectrometer are considered to be peaks with the same m / z value.

[0073] (Item 9) In any one of items 6 to 8, the mass analysis apparatus can be configured such that when the specific peak detection unit enters a specified allowable m / z width on the mass spectrum, it is considered as a peak with the same m / z value.

[0074] According to the mass analysis method described in item 4 and the mass analysis apparatus described in item 9, even when errors, deviations, or variations occur in the apparent m / z value in the mass spectrum due to limitations in the apparatus's own performance (mass resolution), changes in the measurement environment, measurement conditions, etc., peaks generated by the same ion species can be reliably captured and registered as excluded ions. Therefore, the detection of excluded ions can be reliably performed.

[0075] (Item 5) In any one of items 1 to 4, the mass analysis method may be configured to further include a shift control step for controlling the shift of the m / z value over time, wherein in the detection step, the m / z value or m / z range of peaks considered to have the same m / z value on the mass spectrum is changed based on the shift of the m / z value controlled in the shift control step.

[0076] (Item 10) In any one of items 6 to 9, the mass analysis apparatus can be configured such that the specific peak detection unit changes the m / z value or m / z range of peaks that are considered to have the same m / z value on the mass spectrum based on the m / z value shift information over time.

[0077] According to the mass analysis method described in item 5 and the mass analysis apparatus described in item 10, even when the true value of the m / z value remains constant but the m / z value on the mass spectrum drifts due to factors such as changes in the measurement environment or measurement conditions, peaks generated by ion species exhibiting such m / z values ​​can be reliably captured and registered as excluded ions. Thus, the detection of excluded ions can be reliably performed.

[0078] Explanation of reference numerals in the attached figures 1. Liquid Chromatography (LC) Section 11. Mobile phase container 12 Liquid delivery pumps 13 Syringes 14 chromatographic column 2. Quality Analysis (MS) Department 20 Vacuum Chambers 21 Ionization Chamber 211 ESI probe 212 Solvent removal tube 22. First intermediate vacuum chamber 221, 231, 243, 244 Ion Directors 222 cone body 23 Second Intermediate Vacuum Chamber 24 High Vacuum Chamber No. 1 241 Quadruple Quality Filter 242 Collision Pool 25. Second High Vacuum Chamber 251 Orthogonal Accelerator Section 252 Ion Flight Division 253 Reflectors 255 Ion Detector 3. Control / Processing Unit 31 Measurement Condition Setting Section 32 Measurement and Control Department 33 Data Collection Department 34 Mass Spectrometry Generation Section 35. Precursor Selection Section 36 Ion Recognition Unit 37 Exclusion Ion List Storage Unit 4. Power Supply Section 5. Input Section 6. Display section.

Claims

1. A mass analysis method using a mass analysis apparatus capable of performing MS / MS analysis based on data-dependent acquisition, comprising: a detection step of detecting a peak having an m / z value that is continuously observed within a prescribed period based on a mass spectrum obtained by repeatedly performing a full scan measurement; a registration step of registering the m / z value of the peak detected in the detection step or an m / z range including the m / z value in an excluded ion list; a precursor selection step of excluding at least the m / z value or the m / z range registered in the excluded ion list from a precursor selection target in a mass spectrum obtained by the full scan measurement, and extracting an ion satisfying a prescribed precursor selection condition; and a measurement step of performing MS / MS analysis of a precursor ion using the ion extracted in the precursor selection step after the full scan measurement in the precursor selection step.

2. The mass analysis method according to claim 1, further comprising a deletion step of deleting the m / z value or the m / z range registered in the excluded ion list in the registration step from the excluded ion list when a prescribed release condition is satisfied.

3. The mass analysis method according to claim 1, using a mass analysis apparatus in which a chromatograph is connected to a front stage, wherein in the detection step, a peak having an m / z value that is continuously observed within a prescribed period is detected in the chromatograph during a period in which a component derived from a sample introduced into a column of the chromatograph flows out from the column and is introduced into the mass analysis apparatus.

4. The mass analysis method according to claim 1, wherein in the detection step, peaks having m / z values within a prescribed m / z allowable width on a mass spectrum are regarded as peaks having the same m / z value.

5. The mass analysis method according to claim 1, further comprising a shift grasping step of grasping a shift of an m / z value over time, wherein in the detection step, the m / z value or the m / z range of peaks regarded as having the same m / z value on a mass spectrum is changed based on the shift of the m / z value grasped in the shift grasping step.

6. A mass analysis apparatus capable of performing MS / MS analysis based on data-dependent acquisition, comprising: a specific peak detection unit that detects a peak having an m / z value that is continuously observed within a prescribed period based on a mass spectrum obtained by repeatedly performing a full scan measurement; an excluded ion registration unit that registers the m / z value of the peak detected by the specific peak detection unit or an m / z range including the m / z value in an excluded ion list; a measurement unit that performs a full scan measurement, and based on a mass spectrum obtained by the measurement, performs MS / MS analysis of a precursor ion using an ion extracted in a precursor selection unit described later after the full scan measurement; and the precursor selection unit that excludes at least the m / z value or the m / z range registered in the excluded ion list from a precursor selection target in the mass spectrum obtained by the full scan measurement performed by the measurement unit, and extracts an ion satisfying a prescribed precursor selection condition. ​ ​ ​ ​ ​ ​ ​ ​ ​ 7. The mass spectrometric device according to claim 6, wherein the exclusion ion registration section deletes the m / z value or m / z range registered in the exclusion ion list from the exclusion ion list when a prescribed release condition is satisfied.

8. The mass spectrometric device according to claim 6, which is a mass spectrometric device connected to a chromatograph in a preceding stage, wherein the specific peak detection section detects a peak having an m / z value that is continuously observed within a prescribed period of time during a period in which a component derived from a sample introduced into a column of the chromatograph flows out from the column and is introduced into the mass spectrometric device.

9. The mass spectrometric device according to claim 6, wherein the specific peak detection section regards peaks as peaks having the same m / z value when the peaks enter a prescribed m / z allowable width on a mass spectrum.

10. The mass spectrometric device according to claim 6, wherein the specific peak detection section changes the m / z value or m / z range of peaks regarded as having the same m / z value on a mass spectrum in accordance with m / z value shift information over time.

Images