JP2013149554A - Tandem mass spectroscope and its mass spectroscopic method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it easy for a user to input measurement sample characteristics as a setting condition of an MSMS voltage set for each measurement sample before measurement when examining the MSMS voltage setting as a device condition for taking respective MSMS analyses of a variety of measurement samples such as in-vivo polymers and medicine dynamic states before the measurement and making settings for each measurement sample.SOLUTION: A user makes the MSMS voltage settings by specifying at least one of molecule species to be measured and a bond state of a molecule to be measured.

Description

  The present invention relates to a tandem mass spectrometer and a mass spectrometry method using the same.

  Mass spectrometers are broadly divided into devices that mainly perform quantitative analysis and devices that mainly perform qualitative analysis. A typical mass spectrometer that mainly performs quantitative analysis is a quadrupole mass spectrometer having a quadrupole mass spectrometer (QMS) in the apparatus.

  On the other hand, there is a time-of-flight mass spectrometer (hereinafter referred to as TOF / MS) as a mass spectrometer mainly performing qualitative analysis, and it measures the time for ions to reach the detector by flying the measured ions in a vacuum. To perform mass separation. Since TOF / MS has a wide observable mass width and easily obtains a mass spectrum having high resolution, the qualitative analysis performance is improved. However, quantitative analysis performance is often inferior to that of QMS because measurement ions are caused to fly intermittently. In recent years, a hybrid mass spectrometer that combines a plurality of QMS and TOF / MS has been commercialized, and is compatible with both qualitative and quantitative analysis.

  A quadrupole mass spectrometer used in a quadrupole mass spectrometer is also called a Q mass or a mass filter, and consists of four cylindrical electrodes. The cylindrical electrodes are combined with the center of the circle at the apex of the square in the cross section.

  When positive and negative direct currents and high frequency alternating voltages are superimposed and applied to adjacent electrodes of a fixed cylindrical electrode, they pass through the cylindrical electrode while vibrating when charged ions pass through it. Only certain ions according to voltage and frequency pass through the electrode with stable vibration. On the other hand, the other ions vibrate while passing through the electrode and cannot collide with or pass through the electrode. A mass spectrum is obtained by linearly changing the high-frequency AC voltage while keeping the ratio between the DC voltage and the AC voltage constant. Further, when only an AC voltage is applied to the electrode, the ion selectivity is lost, and many ions can pass through the electrode.

  One of the analysis methods of the mass spectrometer is tandem mass spectrometry (hereinafter referred to as MSMS analysis). MSMS analysis is an extremely important analysis method in a mass spectrometer, such as selecting only specific ions from a complex measurement sample to improve the S / N ratio and to enable structural analysis of the measurement sample. For example, MSMS analysis can be realized by using a combination of a plurality of quadrupole mass spectrometers.

  A mass spectrometer that performs MSMS quantitative analysis includes a triple quadrupole mass spectrometer (hereinafter referred to as Triple QMS) having three quadrupole mass spectrometers in the apparatus. Triple QMS can continuously pass specific ions of a measurement sample, and the quantitative analysis performance is improved. In Triple QMS, only the specific ions derived from the measurement sample are taken out by the first quadrupole mass spectrometer, and the ions taken out by the second quadrupole mass spectrometer (applying only the high-frequency AC voltage) collide with gas or the like. To dissociate to generate fragment ions. The resulting fragment ions are then mass separated by a third quadrupole mass spectrometer to obtain a mass spectrum.

  Conventionally, the mass spectrometer shown in patent document 1 is known as a mass spectrometer which performs MSMS quantitative analysis. In Patent Document 1, the triple quadrupole mass spectrometer includes three quadrupole rod sets Q1, Q2, and Q3. The first rod set Q1 sends precursor ions to the second rod set Q2, and the second rod set. The collision gas is supplied to Q2, and ions are trapped and scanned out by the third rod set Q3 to perform mass analysis. Also, the DC voltage and AC voltage to each rod set are controlled.

JP 2005-524111 A

  The purpose of using mass spectrometers in recent years is from the measurement of conventional low molecular weight samples to the structural analysis of biomolecules such as proteome analysis and the measurement of blood drug concentration. It has become. For this reason, the MSMS analysis is particularly regarded as a function of a mass spectrometer. Due to the expansion of the purpose of use, sample types to be measured by mass spectrometers are diversified, such as amino acids, peptides, nucleic acids, residual agricultural chemicals in foods, polyphenols, organic synthetic samples, and pharmaceutical metabolites. When performing MSMS analysis of these measurement samples, the analyst needs to examine the apparatus conditions for each MSMS analysis and make an appropriate setting according to the measurement sample.

  The apparatus conditions necessary for the MSMS analysis include the MSMS voltage applied to the second quadrupole mass spectrometer, the type of gas to be introduced, the amount of gas, and the like. In the conventional mass spectrometer, the MSMS voltage is set for each measurement sample by the user for MSMS analysis. However, the MSMS voltage value varies depending on the type and amount of gas. Further, since the MSMS voltage value is a value unique to the apparatus, for example, when the method of realizing the MSMS analysis method is different or the manufacturer of the mass spectrometer is different, the same measurement sample may have a completely different voltage.

  The mass spectrometer of Patent Document 1 increases the DC voltage of the MSMS voltage stepwise within a predetermined range, and controls the control according to a software program or a predetermined diagram. However, the user can only specify the collision energy spread, and there is a problem that there is no freedom of setting.

  The present invention provides an ion source that applies a charge to a measurement sample, an interface that introduces ions generated by the ion source into the apparatus, and a first quadrupole electrode portion that is applied by superimposing a DC voltage and a high-frequency voltage. And a detector for detecting ions that have passed through the third quadrupole electrode portion, and at least three quadrupole electrode portions of the second quadrupole electrode portion and the third quadrupole electrode portion; A first quadrupole electrode comprising a control device for controlling a DC voltage and a high-frequency voltage applied to the first quadrupole electrode portion, the second quadrupole electrode portion, and the third quadrupole electrode portion; Only the target ions derived from the measurement sample are allowed to pass through the part, the ions derived from the measurement sample passed through the first quadrupole electrode part are dissociated in the second quadrupole electrode part, and fragment ions are generated. A tandem mass spectrometer that allows fragment ions to pass through the quadrupole electrode according to mass The control device is provided with a display device for displaying the measurement sample characteristic, an input device for inputting a specific value of the characteristic, a storage unit storing MSMS voltage data corresponding to the measurement sample characteristic, and an applied voltage setting circuit, The MSMS voltage applied to the second quadrupole electrode unit is calculated and set by the control device by designating a specific value of the measurement sample characteristic displayed on the display device.

  In the tandem mass spectrometer, the storage unit includes a molecular species / voltage database that stores MSMS voltage data corresponding to the molecular species of the measurement sample, a molecular weight / voltage database that stores MSMS voltage data corresponding to the molecular weight, A combined state / voltage database storing MSMS voltage data corresponding to the combined state is provided.

  In the tandem mass spectrometer, the characteristic of the measurement sample displayed and designated on the display device is selected from at least one of the molecular species, molecular weight, and binding state of the measurement sample.

  In the tandem mass spectrometer, the MSMS voltage to be applied to the second quadrupole electrode unit is added to the measurement sample characteristics displayed and designated on the display device.

  In addition, in the tandem mass spectrometer, the input screen displayed on the display device includes a check box for selecting the molecular species of the measurement sample, a specification window for specifying the molecular species, a check box for selecting the molecular weight, and a specification for specifying the molecular weight. A window, a check box for selecting the coupling state, a designation window for designating the coupling state, a check box for selecting the MSMS voltage to be applied to the second quadrupole electrode unit, and a designation window for designating the MSMS voltage. It is characterized by.

  Further, in the tandem mass spectrometer, the input screen displayed on the display device has a graph that displays the MSMS voltage that changes according to the molecular weight for a specific molecular species, and displays an arbitrary user set value on the graph. It is characterized by that.

  Furthermore, an ion source for applying a charge to the measurement sample, an interface for introducing ions generated by the ion source into the apparatus, a first quadrupole electrode unit to which a DC voltage and a high-frequency voltage are applied in a superimposed manner, and a first A detector for detecting ions that have passed through the third quadrupole electrode section, the first quadrupole electrode section including at least three quadrupole electrode sections of the second quadrupole electrode section and the third quadrupole electrode section; A quadrupole electrode unit, a second quadrupole electrode unit, a third quadrupole electrode unit, and a controller for controlling a DC voltage and a high-frequency voltage applied to the third quadrupole electrode unit. Only the target ions derived from the measurement sample are allowed to pass, and the second quadrupole electrode portion dissociates the ions derived from the measurement sample that has passed through the first quadrupole electrode portion, thereby generating fragment ions, and the third 4 A tandem mass spectrometer that allows fragment ions to pass through the electrode at the quadrupole. In the mass spectrometric method, a display window of the control device displays a designated window consisting of at least one of the molecular species, molecular weight, binding state, and MSMS voltage of the measurement sample, and the molecular species and molecular weight of the measurement sample are displayed in the selected designated window. , The at least one specific value of the binding state and the MSMS voltage is input, and the second of the tandem type mass spectrometer is input according to at least one specific value of the molecular species, molecular weight, binding state, and MSMS voltage of the input measurement sample. The MSMS voltage applied to the quadrupole electrode part is calculated and determined.

  Furthermore, in the mass spectrometry method of the tandem mass spectrometer, the molecular species of the measurement sample is designated first, the molecular weight of the measurement sample is designated next, and the binding state of the measurement sample is designated last.

  Further, in the mass spectrometry method of the tandem mass spectrometer, the storage unit of the control device includes a molecular species / voltage database that stores MSMS voltage data corresponding to the molecular species, and a molecular weight / unit that stores MSMS voltage data corresponding to the molecular weight. At least one of a voltage database and a combined state / voltage database storing MSMS voltage data corresponding to the combined state is provided.

  The present invention has an ion source, an interface, and at least three quadrupole electrode portions applied by superimposing a DC voltage and a high-frequency voltage, and detects ions that have passed through the third quadrupole electrode portion. And a control device for controlling a DC voltage and a high-frequency voltage applied to the first quadrupole electrode unit, the second quadrupole electrode unit, and the third quadrupole electrode unit, Only the target ions derived from the measurement sample are allowed to pass through the quadrupole electrode part of the first electrode, fragment ions are generated at the second quadrupole electrode part, and the fragment ions are passed through the third quadrupole electrode part according to the mass. In the tandem-type mass spectrometer to be operated, a display device for displaying the measurement sample characteristics, an input device for inputting a specific value of the characteristics, a storage unit storing MSMS voltage data corresponding to the measurement sample characteristics, and application to the control device A voltage setting circuit is provided for the display device. By specifying the specific value of the indicated measurement sample characteristic, the control device calculates and sets the MSMS voltage to be applied to the second quadrupole electrode so that the user can specify the measurement sample arbitrarily and easily. With this configuration, the condition setting of the mass spectrometer at the time of MSMS analysis is greatly simplified as compared with the conventional one, and it becomes possible to realize a mass spectrometer and a mass spectrometry method that are easy to use.

The schematic diagram which shows the triple quadrupole-type mass spectrometer in the Example of this invention. The block diagram which shows the structure of the mass spectrometer control apparatus in the Example of this invention. The flowchart which shows the MSMS mass spectrometry method in the Example of this invention. Explanatory drawing which shows the screen which sets MSMS conditions in the Example of this invention. The graph which shows the molecular weight and MSMS voltage for every molecular species in this invention.

  Hereinafter, the present invention will be described with reference to examples and drawings.

  In the mass spectrometer MS shown in FIG. 1, a measurement sample supplied from a pump such as a liquid chromatograph is ionized by an ion source 100. Since the ion source is under atmospheric pressure and the mass spectrometer operates in a vacuum atmosphere, ions 110 are introduced into the mass spectrometer through the interface 200 between the atmosphere and the vacuum atmosphere. The mass spectrometer MS has three quadrupole electrode portions 400, 410, and 420 that are quadrupole mass spectrometers, and each quadrupole electrode portion has quadrupole electrodes 300, 310, and 320, respectively.

  There are various methods of MSMS analysis by TripleQMS, and typical measurement methods are shown below.

  Although ions generated from the ion source have various masses, only the target ions derived from the measurement sample are selectively passed through the first quadrupole electrode unit 400. A collision gas 800 (nitrogen gas, argon gas, or the like) for dissociating target ions is introduced into the second quadrupole electrode portion 410 from a supply source through a gas line 810. The quadrupole electrode 310 of the second quadrupole electrode portion 410 normally applies only an AC voltage to lose mass selectivity, and collides target ions that have passed through the first quadrupole electrode portion 400 with the gas. To generate fragment ions. Among the MSMS conditions, the MSMS voltage is a potential difference applied to the second quadrupole electrode portion 410. A DC voltage may be applied to the second quadrupole electrode 310 during MSMS analysis.

  The generated fragment ions pass through the second quadrupole electrode portion 410 and enter the third quadrupole electrode portion 420. When a high-frequency voltage and a DC voltage that pass the target fragment ions are applied to the third quadrupole electrode 320, only the target fragment ions pass through the third quadrupole electrode portion 420. The target fragment ions that have passed through are detected by the detector 500. Data is sent from the circuit board 600 on which an AMP, an AD converter, and the like are mounted to the data processing unit 700, whereby MSMS analysis is performed. Reference numeral 10 denotes a control device that controls each of the above components.

  FIG. 2 shows the configuration of the control device 10. While viewing the display device 2, the user selects at least one of the molecular species, molecular weight, and binding state of the measurement sample using the input device 3. In accordance with this, the selection circuit 4 reads a predetermined corresponding MSMS voltage from any one of the molecular species / voltage database 5, the molecular weight / voltage database 6, and the binding state / voltage database 7, and outputs it to the applied voltage setting circuit 8. . The applied voltage setting circuit 8 instructs the voltage generator 9 on the value of the designated MSMS voltage and outputs it as the MSMS voltage. The output MSMS voltage is input to the second quadrupole electrode portion 410 of FIG. 1, and fragment ions are formed.

  The user may directly specify the MSMS voltage by inputting the value while viewing the display device 2.

  The control device 10 is typically composed of an input device such as a keyboard, a display device such as a display, a computer having a storage device, and a mass spectrometry program executed on the computer. These may be constituted by dedicated hard logic circuits.

  FIG. 3 is a flowchart showing the MSMS mass spectrometry method in the embodiment of the present invention. In FIG. 3, first, a measurement sample setting screen is displayed on the display device 2 of FIG.

  When the user selects a molecular species in S20, the molecular species / voltage database is automatically selected in S21, and when the user designates a specific molecular species in S22, the corresponding MSMS voltage is automatically selected in S23. In step S60, the MSMS voltage is output. In step S70, the MSMS voltage is applied to the second mass spectrometer, and fragment ions are generated.

  When the user selects a molecular weight in S30, the molecular weight / voltage database is automatically selected in S31, and when the user designates a specific molecular weight in S32, the corresponding MSMS voltage is automatically set in S33. In step S60, the MSMS voltage is output. In step S70, the MSMS voltage is applied to the second mass spectrometer, and fragment ions are generated.

  Further, when the user selects a molecular weight at S40, the binding state / voltage database is automatically selected at S41, and when the user designates a specific binding state at S42, the corresponding MSMS voltage is automatically selected at S43. In step S60, the MSMS voltage is output. In step S70, the MSMS voltage is applied to the second mass spectrometer, and fragment ions are generated.

  Further, when the user designates the final MSMS voltage in S50, the MSMS voltage is immediately output in S60 and applied to the second mass spectrometer in S70 to generate fragment ions.

  FIG. 3 shows a flow chart in the case of selecting any one of the measurement sample characteristics consisting of the molecular species, molecular weight, and binding state. In addition to this, any two or three of the above measurement sample characteristics are selected. There is also a flow diagram in the case of combining all, and the execution order of the measurement sample characteristics can also be selected.

  FIG. 4 shows an input screen 1000 for measurement sample setting for setting the MSMS voltage to be applied to the second quadrupole electrode portion 410 displayed on the display device 2. In FIG. 4, as a measurement sample setting, a molecular species is selected by a check box 1010, and a specific molecular species is input by a designation window 1011 including a pull-down menu. In addition, a molecular weight is selected by a check box 1020 and a specific molecular weight is input by a designation window 1021. In addition, a combined state is selected by a check box 1030 and a specific combined state is input in a designation window 1031.

  Further, similarly to the conventional example, an arbitrary MSMS voltage can be directly set by the check box 1040 and the designation window 1041.

  For example, Peptide, Small molecular, Sugar chain, Agricultural chemical, or the like can be selected as the molecular species. When only this molecular species is selected, a typical constant voltage, which is data stored in advance in the database, is set as the MSMS condition according to each molecular species (specific value).

  As for the molecular weight, the user inputs a specific value of an approximate molecular weight of a measurement sample known in advance. The relationship between the molecular weight and the MSMS voltage is normally positively correlated with the voltage increasing as the molecular weight increases, and the MSMS voltage is set according to the molecular weight-MSMS condition voltage graph created in advance.

  For the binding state, the user inputs the binding state of a site to be dissociated, such as a double bond, a sulfur bond, or a phosphate bond, in the target ion of the measurement sample. Since the bond energy is uniquely determined by the type of chemical bond, a constant voltage corresponding to the bond energy created in advance is set as the MSMS voltage. It is also possible to set the MSMS voltage directly as in the conventional case.

  In actual MSMS analysis, the molecular species is first determined, then the molecular weight is determined, and then the binding state of the measurement sample in which these molecular species and molecular weight are determined is determined. The MSMS analysis of the measurement sample can be performed appropriately and efficiently.

  FIG. 5 is a graph shown on the input screen for determining the MSMS voltage corresponding to the molecular weight for each molecular species displayed on the display device 2.

  In FIG. 5, the MSMS voltage tends to increase with increasing molecular weight, and the MSMS voltage varies greatly with different molecular species. Therefore, a voltage setting graph is created for each molecular species based on data prepared in advance. The In FIG. 5, for molecular species 1, voltages of V1s (V) at the minimum molecular weight and V1e (V) at the maximum molecular weight are set. In the molecular species 2, voltages of V2s (V) at the minimum molecular weight and V2e (V) at the maximum molecular weight are set.

  In the above method, an approximate MSMS voltage can be set. However, in the case of a molecular species for which sufficient data has already been obtained, a new setting curve can be created by the user entering the molecular weight and the MSMS voltage. Is also possible. By creating a user setting curve, the MSMS voltage is optimized and the measurement sensitivity during MSMS measurement is improved.

2 ... Display device 3 ... Input device 4 ... Selection circuit 5 ... Molecular species / voltage database 6 ... Molecular weight / voltage database 7 ... Coupling state / voltage database 8 ... Applied voltage Setting circuit 9 ... Voltage generator 10 ... Control device 100 ... Ion source 110 ... Flow of ions generated in the ion source 200 ... Interface 300 ... First quadrupole electrode 310 ... Second quadrupole electrode 320 ... Third quadrupole electrode 400 ... First quadrupole electrode section 410 ... Second quadrupole electrode section 420 ... Third quadrupole electrode unit 500... Detector 600... Circuit unit 700 such as AMP, AD conversion, PC communication... Data processing unit 800 such as PC... MSMS analysis collision gas 810.・ ・ MSMS analysis gas line 1000 ・Measurement sample setting screen for setting the · MSMS analysis conditions

Claims (9)

An ion source for applying a charge to the measurement sample, an interface for introducing ions generated by the ion source into the apparatus, a first quadrupole electrode unit applied with a DC voltage and a high-frequency voltage superimposed, and a second A detector for detecting ions that have passed through the third quadrupole electrode portion, and at least three quadrupole electrode portions of the quadrupole electrode portion and the third quadrupole electrode portion; A control device for controlling a DC voltage and a high-frequency voltage applied to one quadrupole electrode portion, a second quadrupole electrode portion, and a third quadrupole electrode portion, and the first quadrupole electrode Only the target ions derived from the measurement sample are allowed to pass through the part, and the ion derived from the measurement sample that has passed through the first quadrupole electrode part is dissociated in the second quadrupole electrode part to generate fragment ions. The fragment ions are allowed to pass through the third quadrupole electrode according to the mass. In tandem mass spectrometer comprising,
The control device is provided with a display device for displaying a measurement sample characteristic, an input device for inputting a specific value of the characteristic, a storage unit storing MSMS voltage data corresponding to the measurement sample characteristic, and an applied voltage setting circuit, Tandem mass spectrometry characterized in that the MSMS voltage applied to the second quadrupole electrode unit is calculated and set by the control device by designating a specific value of the measurement sample characteristic displayed on the display device apparatus.   2. The tandem mass spectrometer according to claim 1, wherein the storage unit stores a molecular species / voltage database storing MSMS voltage data corresponding to a molecular species of a measurement sample, and MSMS voltage data corresponding to a molecular weight. A tandem mass spectrometer comprising a molecular weight / voltage database and a binding state / voltage database storing MSMS voltage data corresponding to the binding state.   The tandem mass spectrometer according to claim 1 or 2, wherein a measurement sample characteristic displayed and designated on the display device is selected from at least one of a molecular species, a molecular weight, and a binding state of the measurement sample. A tandem mass spectrometer.   4. The tandem mass spectrometer according to claim 1, wherein an MSMS voltage applied to the second quadrupole electrode portion is added to a measurement sample characteristic displayed and designated on the display device. 5. A tandem mass spectrometer.   The tandem mass spectrometer according to any one of claims 1 to 4, wherein the input screen displayed on the display device includes a check box for selecting a molecular species of the measurement sample, and a designation window for designating the molecular species. A selection box for selecting a molecular weight, a designation window for designating the molecular weight, a check box for selecting a binding state and a designation window for designating the binding state, and an MSMS voltage to be applied to the second quadrupole electrode section. A tandem mass spectrometer having a check box and a designation window for designating an MSMS voltage.   The tandem mass spectrometer according to any one of claims 1 to 4, wherein the input screen displayed on the display device has a graph that displays an MSMS voltage that changes according to the molecular weight of a specific molecular species. An arbitrary user set value is displayed on the graph. A tandem mass spectrometer. An ion source for applying a charge to the measurement sample, an interface for introducing ions generated by the ion source into the apparatus, a first quadrupole electrode unit applied with a DC voltage and a high-frequency voltage superimposed, and a second A detector for detecting ions that have passed through the third quadrupole electrode portion, and at least three quadrupole electrode portions of the quadrupole electrode portion and the third quadrupole electrode portion; A control device for controlling a DC voltage and a high-frequency voltage applied to one quadrupole electrode portion, a second quadrupole electrode portion, and a third quadrupole electrode portion, and the first quadrupole electrode Only the target ions derived from the measurement sample are allowed to pass through the part, and the ion derived from the measurement sample that has passed through the first quadrupole electrode part is dissociated in the second quadrupole electrode part to generate fragment ions. The fragment ions are allowed to pass through the third quadrupole electrode according to the mass. A mass spectrometry method of tandem mass spectrometer comprising,
A designated window consisting of at least one of the molecular species, molecular weight, binding state, and MSMS voltage of the measurement sample is displayed on the display device of the control device,
Enter at least one specific value of the molecular species, molecular weight, binding state, and MSMS voltage of the measurement sample into the selected designated window.
Calculate and determine the MSMS voltage to be applied to the second quadrupole electrode portion of the tandem mass spectrometer according to at least one specific value of the molecular species, molecular weight, binding state, and MSMS voltage of the input measurement sample A mass spectrometry method for a tandem mass spectrometer.   The mass spectrometric method for a tandem mass spectrometer according to claim 7, wherein the molecular species of the measurement sample is first designated, the molecular weight of the measurement sample is designated next, and the binding state of the measurement sample is finally designated. A mass spectrometric method for a tandem mass spectroscope characterized by specifying.   9. The mass spectrometric method for a tandem mass spectrometer according to claim 7 or 8, wherein the storage unit of the control device corresponds to a molecular species / voltage database storing MSMS voltage data corresponding to the molecular species and a molecular weight. A mass analysis method for a tandem mass spectrometer, comprising at least one of a molecular weight / voltage database for storing MSMS voltage data and a binding state / voltage database for storing MSMS voltage data corresponding to the binding state .

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