JP2005221250A - Method and apparatus for analyzing mass spectrum - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new mass spectrum analyzing method capable of easily performing the analysis of a mass spectrum, wherein a plurality of kinds of peaks of impurity additive ions appear at the same time, without requiring skill, and a mass spectrum analyzer. <P>SOLUTION: The peaks of a plurality of additive ions are detected on the basis of the comparison of the data inputted from an input part with the data registered in a data base part and the candidate of a compositional formula of additive ions is calculated according to a precise mass operating method from the mass charge ratio of a plurality of the detected additive ions. In the calculated compositional formula, the compositional formulae of the residual parts from which elements constituting an adduct are removed are mutually compared with respect to a plurality of additive ions and, after comparison, the compositional formula with a high degree of coincidence is judged to the compositional formula of non-additive ions observed in this system to determine the compositional formula of sample ions. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method and apparatus for analyzing a spectrum obtained by a mass spectrometer, and in particular, obtained by mass spectrometry of ions added with mobile phase solvent and impurity molecules contained in the mobile phase solvent. The present invention relates to a method and an apparatus for analyzing a spectrum.

  When analyzing the mass of a molecule contained in a sample (hereinafter referred to as a sample molecule. The sample molecule may be abbreviated as M) using a mass spectrometer (hereinafter abbreviated as MS), Ionization is performed, but there are various ionization methods. Among them, when ionization is performed, an ionization method in which ions are generated by adding a mobile phase solvent or impurities contained in the mobile phase solvent to sample molecules. There is.

  A typical example of such an ionization method is an atmospheric pressure ionization method (API) used as an interface between liquid chromatography (hereinafter abbreviated as LC) and MS.

  There are two types of atmospheric pressure ionization methods: electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI). In each case, a sample molecule and a mobile phase solvent such as methanol, acetonitrile, and acetic acid are used. Ionization takes place by proton transfer between the two.

When positive ion detection is performed by MS, proton-added ion [M + H] ^{+ in} which proton H ⁺ is added to sample molecule M is detected. When negative ion detection is performed by MS, proton ion is detected from sample molecule M. Proton desorption ions [M−H] ⁻ from which H ⁺ is desorbed are detected.

JP 2002-15697 A JP 2002-245962 A

By the way, if the ions generated by the API are only proton addition ions [M + H] ⁺ or proton desorption ions [M−H] ⁻ , there are few problems, but proton addition ions or proton desorption ions. In addition to isolated ions, mobile phase solvents and ions in which impurities contained in the solvent are added to sample molecules are generated, and such added ions are detected by MS and often appear on the spectrum. .

In the following, the mobile phase solvent and ions in which impurities contained in the solvent are added to the sample molecule are referred to as impurity addition ions, and impurity addition ions, proton addition ions, and proton desorption ions are collectively referred to. And referred to as additional ions. In addition, a substance added to the sample molecule in the additional ion is referred to as an adduct. For example, in proton adduct ions, protons are adducts, and in impurity addition ions [M + NH ₄ ] ⁺ , ammonium ions are adducts as described later. For proton desorption ions as well, protons are referred to as adducts for convenience.

For example, when ionization is performed by ESI using methanol as a mobile phase solvent and positive ions are detected by MS, positive impurity-added ions in which ammonium ions are added to sample molecules M in addition to proton-added ions [M + H] ⁺ It is empirically known that M + NH ₄ ] ⁺ and / or positive impurity addition ions [M + Na] ^{+ in} which sodium ions are added to the sample molecule M may be detected.

In addition, when ionization is performed by APCI using methanol as a mobile phase solvent and positive ions are detected by MS, positive ions in which proton H ⁺ and methanol molecules are added to sample molecules M in addition to proton-added ions [M + H] ⁺ are detected. It is empirically known that impurity-added ions [M + H + CH ₃ OH] ⁺ may be detected.

Further, when ionization is performed by ESI using a mobile phase solvent containing formic acid and negative ions are detected by MS, negative impurities in which formate ions are added to sample molecule M in addition to proton desorption ions [M−H] ⁻ It is empirically known that additional ions [M + HCOO] ⁻ may be detected.

  Thus, when ionization is performed by API and mass spectrometry is performed, the peak of impurity addition ions appears in the spectrum in addition to the peak of proton addition ions or proton desorption ions. In many cases, it is difficult to determine the molecular weight of the polymer and to analyze the spectrum.

  Therefore, it is very difficult to analyze the spectrum obtained by ionizing with API and performing mass spectrometry with MS. To determine the molecular weight of a sample molecule based on the spectrum, Not only is experience necessary, but there is even a problem that the analysis result of the spectrum may differ depending on the degree of experience of the analyst.

  The above describes the case where ionization is performed by API. However, it is not only API that generates impurity-added ions, but also chemical ionization (CI), fast atom bombardment (FAB), matrix Impurity-added ions may also be generated when ionized by assisted laser ionization (MALDI), field desorption (FD), or the like. The same problem as described above also occurs when analyzing the obtained mass spectrum. In addition, when a plurality of types of impurity-added ions appear simultaneously, the analysis is further troublesome.

  An object of the present invention is to provide a new mass spectrum analysis method capable of easily analyzing a mass spectrum in which peaks of a plurality of types of impurity-added ions appear simultaneously without requiring skill, in view of the above points. And providing an apparatus.

In order to achieve this object, the method for analyzing a mass spectrum according to the present invention includes:
A mass spectrum analysis method applied to a system in which a plurality of types of additional ions are observed simultaneously, and includes the following steps:
(1) Ionization method, detection polarity of mass spectrometer, and information on mobile phase solvent, ionization method, detection polarity of mass spectrometer, mobile phase solvent, and their information registered in the database section of mass spectrometer A step of detecting peaks of a plurality of additional ions included in detection data obtained by a mass spectrometer by comparing with information on the additional ions expected to be detected under conditions;
(2) A step of obtaining a candidate of a composition formula of an additional ion from a mass-to-charge ratio of the detected additional ions by a precise mass calculation method,
(3) In the obtained composition formula group, a step of comparing the composition formula of the remaining part from which the elements constituting the adduct are removed with a plurality of additional ions,
(4) After comparing, the step of judging the composition formula having a high degree of coincidence as the composition formula of non-addition ions observed in the system;
The composition formula of ions is determined through the four steps.

  In addition, the detection of the peak of the additional ion is performed in the measurement system, in which the value of the difference in mass to charge ratio between at least two peaks observed in the high mass to charge ratio region may be observed in the measurement system. It is characterized in that it is performed based on whether or not the two types of values of the difference in mass-to-charge ratio between the adduct ions coincide with each other.

  Further, the mass spectrum is generated by a soft ionization method.

  Further, the soft ionization method is one of API, CI, FAB, MALDI, and FD.

  The API is characterized in that it is either ESI or APCI used as an interface between the liquid chromatography and the mass spectrometer.

Moreover, the mass spectrum analyzer according to the present invention includes:
A mass spectrum analyzer applied to a system in which multiple types of additional ions are observed simultaneously.
(1) An input unit for inputting information on the ionization method, the detection polarity of the mass spectrometer, and the mobile phase solvent,
(2) Ionization method, detection polarity of mass spectrometer, mobile phase solvent, and information on additional ions expected to be detected under those conditions are registered for comparison with the information input from the input unit. Database department,
(3) Based on the comparison between the information input from the input unit and the information registered in the database unit, the peaks of a plurality of additional ions in the detection data obtained by the mass spectrometer are detected and detected. From the mass-to-charge ratio of a plurality of adduct ions, a candidate for a composition formula of the adduct ion is obtained by an accurate mass calculation method, and in the obtained composition formula group, the composition formulas of the remaining part from which the elements constituting the adduct are removed are plural. A comparison unit that compares the addition ions with each other, and after the comparison, determines the composition formula having a high degree of coincidence as the composition formula of the non-addition ions observed in the system, and determines the composition formula of the sample ions,
It is characterized by having three units.

  In addition, the detection of the peak of the adduct ion is performed using at least two types of values in which the mass-to-charge ratio difference between at least two peaks observed in the high mass-to-charge ratio region may be observed in the measurement system. It is characterized in that it is performed based on whether or not it matches the value of the difference in mass-to-charge ratio between additional ions.

  Further, the mass spectrum is generated by a soft ionization method.

  Further, the soft ionization method is one of API, CI, FAB, MALDI, and FD.

  The API is characterized in that it is either ESI or APCI used as an interface between the liquid chromatography and the mass spectrometer.

According to the mass spectrum analysis method of the present invention, the mass spectrum analysis method is applied to a system in which a plurality of types of additional ions are simultaneously observed, and includes the following steps:
(1) Ionization method, detection polarity of mass spectrometer, and information on mobile phase solvent, ionization method, detection polarity of mass spectrometer, mobile phase solvent, and their information registered in the database section of mass spectrometer A step of detecting peaks of a plurality of additional ions included in detection data obtained by a mass spectrometer by comparing with information on the additional ions expected to be detected under conditions;
(2) A step of obtaining a candidate of a composition formula of an additional ion from a mass-to-charge ratio of the detected additional ions by a precise mass calculation method,
(3) In the obtained composition formula group, a step of comparing the composition formula of the remaining part from which the elements constituting the adduct are removed with a plurality of additional ions,
(4) After comparing, the step of judging the composition formula having a high degree of coincidence as the composition formula of non-addition ions observed in the system;
Since the ion composition formula is determined through these four steps, the analysis of the mass spectrum in which the peak of the impurity added ion appears can be easily performed without requiring skill.

Moreover, according to the mass spectrum analyzer of the present invention, the mass spectrum analyzer is applied to a system in which a plurality of types of additional ions are simultaneously observed, and includes the following units:
(1) An input unit for inputting information on the ionization method, the detection polarity of the mass spectrometer, and the mobile phase solvent,
(2) Ionization method, detection polarity of mass spectrometer, mobile phase solvent, and information on additional ions expected to be detected under those conditions are registered for comparison with the information input from the input unit. Database department,
(3) Based on the comparison between the information input from the input unit and the information registered in the database unit, the peaks of a plurality of additional ions in the detection data obtained by the mass spectrometer are detected and detected. From the mass-to-charge ratio of a plurality of adduct ions, a candidate for a composition formula of the adduct ion is obtained by an accurate mass calculation method, and in the obtained composition formula group, the composition formulas of the remaining part from which the elements constituting the adduct are removed are plural. A comparison unit that compares the addition ions with each other, and after the comparison, determines the composition formula having a high degree of coincidence as the composition formula of the non-addition ions observed in the system, and determines the composition formula of the sample ions,
Thus, the analysis of the mass spectrum in which the peak of the impurity-added ion appears can be easily performed without requiring skill.

  Hereinafter, embodiments of the invention will be described with reference to the drawings. First, a method and apparatus for easily performing analysis for selecting an ion peak derived from an impurity-added ion from a mass spectrum in which the peak of the impurity-added ion appears will be described without requiring experience. In the following description, a case where a spectrum obtained by detecting ions ionized by API by MS is analyzed will be described. However, the present invention uses ions ionized by CI, FAB, MALDI, or FD as MS. The present invention can also be applied to the case of analyzing a mass spectrum obtained by detecting with 1.

  FIG. 1 is a diagram showing an embodiment of a mass spectrum analyzer according to the present invention, in which 1 is an input unit, 2 is a control unit, 3 is a display unit, 4 is an interface (hereinafter referred to as I / F). 5 is a storage unit, 6 is a database unit, and 7 is a bus. Hereinafter, the database is referred to as DB.

  First, each part of the mass spectrum analyzer shown in FIG. This mass spectrum analyzer has a configuration in which an input unit 1, a control unit 2, a display unit 3, an I / F 4, a storage unit 5, and a DB unit 6 are connected by a bus 7.

  The input unit 1 includes a keyboard and a mouse. The control unit 2 is composed of an MPU and its peripheral circuits, and manages the operation of the spectrum analyzer, and in particular, software for executing the spectrum analysis process described below, and DB update Software that executes the process is installed.

  The display unit 3 is a monitor and is configured by a display device capable of screen display such as a color CRT or a color liquid crystal display device. The input unit 1, the control unit 2, and the display unit 3 constitute a graphical user interface (GUI).

  The I / F 4 is an interface for taking in detection data detected by the MS through a communication line. Here, the MS detection data is taken from the communication line via the I / F 4, but the MS detection data may be stored in an appropriate storage medium such as a flexible disk and read. Of course. The detection data fetched from the I / F 4 is temporarily stored in the storage unit 5 under the control of the control unit 2.

  The storage unit 5 is for storing various data such as captured MS detection data and spectrum analysis results.

  The DB unit 6 has additional ions that are expected to be detected and additional ion information about these additional ions for each combination of ionization method, ion polarity detected by MS, and type of mobile phase solvent. The written DB is registered. Here, the difference in mass-to-charge ratio of the adduct is used as additional ion information. More specifically, when two additional ions are selected from the additional ions written in the item of additional ions, the difference in mass-to-charge ratio of the adducts of the two additional ions is used as additional ion information. Shall be used.

  FIG. 2 shows an embodiment of the DB structure. FIG. 2 is a table for explaining a method of correctly discriminating peaks derived from additional ions and determining the correct molecular weight of a compound appearing in a mass spectrum from the mass-to-charge ratio of those additional ions. Each item in FIG. 2 will be described as follows. “Ionization method” is an item indicating whether ionization is performed by ESI or APCI. “Polarity” is an item indicating the polarity of the charge of ions detected by MS, “+” indicates detection of positive ions, and “−” indicates detection of negative ions. In the item “mobile phase solvent”, the type of LC mobile phase solvent used immediately before ionizing the sample molecules is written.

In the “additional ion” item, the type of addition ion that is highly likely to be detected by MS is determined based on the combination of the ionization method, polarity, and mobile phase solvent. For example, according to the top column of FIG. 4, when the ionization method is ESI, the polarity is positive, and the mobile phase solvent is methanol, proton-added ions [M + H] ⁺ , impurity-added ions [M + NH ₄ ] ⁺ , And three types of other impurity addition ions [M + Na] ⁺ are written as addition ions that are highly likely to be detected by MS. As shown in this table, what kind of adduct ion can be detected when what kind of mobile phase solvent is used, what kind of ionization method is adopted, and when ion is detected with positive or negative polarity? I know from experience.

  In the item “mass-to-charge ratio difference”, the value of the mass-to-charge ratio difference between a plurality of additional ions that is empirically known to be observed is written. For example, with regard to the top column in FIG. 2, since there is a high possibility that three types of additional ions are observed, there are three combinations when selecting two of these additional ions, The adduct mass-to-charge ratio difference for each of the three combinations is written. Specifically, the mass to charge ratio difference between protons and ammonium ions 17, the mass to charge ratio difference between protons and sodium ions 22, and the mass charge between ammonium ions and sodium ions. A ratio of 5 is written. The same applies to the other columns. When there are only two types of adduct ions that are likely to be observed, only the difference in mass-to-charge ratio of adducts of these two types of adduct ions is written.

Now, the method of discriminating the peak derived from an adduct ion presented by the present application is the two specific ion methods observed in the high mass region of the mass spectrum obtained under the predetermined ionization method, polarity, and mobile phase solvent. Determine whether the value of the peak interval matches the value of the mass-to-charge ratio difference described in the column that satisfies the measurement conditions for the predetermined ionization method, polarity, and mobile phase solvent in FIG. For example, the two peaks are determined to be peaks derived from the additional ions described in FIG. By this, it can be understood what the adduct of the adduct ion is, so by subtracting the value of the mass-to-charge ratio of the adduct itself from the value of the mass-to-charge ratio of the peak determined to be the peak derived from the adduct ion, The value of the mass-to-charge ratio of the original molecular ion [M] ⁺ can be determined, that is, the molecular weight of the target compound. This method is very effective because it can be carried out with at least two additional ion peaks.

For example, in the measurement conditions shown in the top column of FIG. 2, that is, the measurement conditions such that the ionization method is ESI, the polarity is positive, and the mobile phase solvent is methanol, the high mass region of the mass spectrum is displayed. Assuming that the value of the interval between two specific peaks observed is 17, these two peaks are ammonium ions in order from the peak on the higher mass region side based on the value of the difference in mass-to-charge ratio. It can be assigned to be a peak of ion-added ion [M + NH ₄ ] ^{+ and} a peak of proton-added ion [M + H] ⁺ . Then, by subtracting the mass-to-charge ratio of ammonium ions and the mass-to-charge ratio of protons from the mass-to-charge ratio values of the respective peaks, the value of the mass-to-charge ratio of the original molecular ion [M] ⁺ . The true molecular weight of the target compound M can be determined.

  Next, in order to determine the composition formula of the target compound M from the true molecular weight of the target compound M thus determined, the following operation is performed. First, when a standard sample such as PFK (perfluorokerosene) is added to the measurement sample during measurement of the mass spectrum of the target compound M, the accurate mass up to 5 digits after the decimal point is determined for multiple impurity-added ions. can do. Therefore, by such a method, accurate mass measurement is performed for all of the plurality of impurity added ions, and composition estimation is performed for the measured accurate mass by the accurate mass calculation method. Candidate). In the group of estimated composition formulas obtained, the composition formula of the remaining part from which the elements constituting the adduct were removed was compared between multiple additional ions. If the composition formula of the observed non-addition ions is determined, the composition formula of the sample ions can be determined. By this method, not only the determination of the ion peak derived from the adduct ion and the determination of the true molecular weight of the target compound M, but also the composition formula of the sample ion itself that is the source of the adduct ion can be determined efficiently. Is possible. The details of the present invention after the composition estimation by the precise composition calculation method will be described below based on another example.

For example, when a certain compound M is measured by a positive ion ESI method using a methanol solvent, a mass spectrum showing a remarkable ion peak is obtained at positions where the mass to charge ratio is 1154, 1176, 1192. It is assumed that these peaks are derived from [M + H] ⁺ ions, [M + Na] ⁺ ions, and [M + K] ⁺ ions, respectively, by analyzing the value of the difference in mass-to-charge ratio between the peaks described above. . Then, in order to know the composition formula of the compound M giving such a plurality of impurity-added ions, it is assumed that the composition estimation is performed by the accurate mass calculation method for all of the accurate masses of these three ions, 1154.59960, 1176.57406, and 1119.54165.

FIG. 3 shows the result. The left column of the figure shows the measured accurate mass of the impurity-added ion, and the second column from the left end of the figure has a value very close to the accurate mass of the impurity-added ion obtained by the accurate mass calculation method. Calculated accurate mass, the third column from the left end of the figure is the mass difference (mmu) between the measured accurate mass of the impurity-added ions and the calculated accurate mass, and the right end column of the figure is the estimated composition that is the source of the calculated accurate mass This is a formula (a candidate for a true composition formula). As estimation conditions, the number of elements range is
C: 45-60,
H: 75-85,
O: 0 to 20,
N: 0 to 13,
Na: 0 to 1,
K: 0 to 1,
The allowable mass difference was set to 10 mmu.

As is clear from FIG. 3, for the [M + H] ⁺ ion that gives an accurate mass of 1154.59960, 15 estimated composition formulas (true composition formula candidates), and for the [M + Na] ⁺ ion that gives an accurate mass of 1176.57406 There are 23 estimated composition formulas (true composition formula candidates) and 22 estimated composition formulas (true composition formula candidates) for [M + K] ⁺ ions that give an accurate mass of 1119.54165. An algorithm for selecting the most appropriate composition formula from these composition formula candidates is as follows.

First, in the estimated composition formula group, the composition formulas of the remaining portions after removing the elements (here, H, Na, and K) constituting the impurity adducts are compared between the additional ions. To do. Then
The combination of “C57H80N13O13” and “C57H79N13Na1O13” marked with ○.

  Combination of “C56H84N9O17” and “C56H83N9Na1O17” marked with Δ.

  Combination of “C58H79N11Na1O14” and “C58H79N11K1O14” marked with □.

  Combination of “C57H83N7Na1O18” and “C57H83N7K1O18” marked with ◇.

  ● Combination of “C53H79N13Na1O16” and “C53H79N13K1O16” marked.

Combination of “C52H83N9Na1O20” and “C52H83N9K1O20” marked with ▲.
It can be seen that the estimated composition formulas of the remaining portions from which the elements (ie, H, Na, K) constituting the impurity adduct are removed are the same in the six combinations. In addition, three estimated composition formulas marked with ◎,
"C51H84N11O19"
"C51H83N11Na1O19"
"C51H83N11K1O19"
As for the combination, the composition of the remaining part of all three of [M + H] ⁺ ion, [M + Na] ⁺ ion, and [M + K] ⁺ ion after removing the elements (H, Na, K) constituting the impurity adduct It can be seen that the expressions match. In this way, it is estimated that the estimated composition formula having a higher degree of coincidence of the remaining portions after removing the elements (H, Na, K) constituting the impurity adduct is closer to the true composition formula of the target compound M. The

Therefore, by using a computer, an impurity adduct (for example, H ⁺ , NH ₄ ⁺ , Na ⁺ , K ⁺ , CH ₃ OH, CH from the estimated composition formula groups for a plurality of impurity added ions as shown in FIG. ₃ CN, N (CH ₂ CH ₃ ) ₃ , HCOO ⁻ , CH ₃ COO ⁻ , CF ₃ COO ⁻ , Cl ^−, etc.) are removed, and the estimated composition formula is the same in the remaining composition formula By performing a combination search that picks up a target, a beginner can easily select an estimated composition formula that is closest to the true composition formula of the target compound M from among a large number of estimated composition formula groups without requiring skill. it can. In the example of FIG.
"C51H83N11O19"
It can be said with the maximum possibility that this composition formula is the true composition formula of the target compound M.

  In order to display such a combination search result on the display screen, it is not always necessary to display only one composition formula. For example, the probability is high based on the condition input as the search condition. Needless to say, a plurality of estimated composition formulas hit in the search may be displayed in order of priority from the composition formula.

Also, when setting priorities,
1. A combination in which the composition formulas of the remaining portions obtained by removing the elements constituting the impurity adduct are the same with a larger amount of impurity addition ions is dominant.

2. A combination having a small mass difference between the impurity-added ions whose ion peak has the highest intensity is regarded as dominant.

3. A combination having a small average value of the mass difference of each impurity added ion is advantageous.
Priorities may be given to search results based on search conditions such as

  FIG. 4 summarizes the above analysis method in a flowchart. In this analysis method, first, accurate mass measurement of a sample is performed (S-1). Next, an accurate mass spectrum is acquired (S-2). Next, additional ion information is acquired based on the value of the difference in mass-to-charge ratio between the observed ion peaks (S-3). Next, composition estimation conditions for estimating the composition formula of the target ions are set (S-4). Next, an estimated composition formula is calculated from the accurate mass of the target ion by the accurate mass calculation method (S-5). Next, in the estimated composition formula group thus obtained, a combination composition search of additional ions is performed in which the composition formula of the remaining part from which the elements constituting the adduct are removed is compared between a plurality of additional ions (S-6). Finally, the result of hit in the combination composition search is displayed with priorities (S-7). By following the above procedure, the composition formula of the target ion can be determined from the mass spectrum.

  It can be widely used for analysis of mass spectra including a plurality of additional ions.

It is a figure which shows the mass spectrum analyzer concerning this invention. It is a figure which shows an example of the database registered into the database part of the mass spectrum analyzer concerning this invention. It is a figure which shows the example of an analysis of the mass spectrum concerning this invention. It is a figure which shows the mass-spectrum analysis method concerning this invention.

Explanation of symbols

1: input unit, 2: control unit, 3: display unit, 4: interface (I / F), 5: storage unit, 6: database unit, 7: bus

Claims (10)

A mass spectrum analysis method applied to a system in which a plurality of types of additional ions are observed simultaneously, and includes the following steps:
(1) Ionization method, detection polarity of mass spectrometer, and information on mobile phase solvent, ionization method, detection polarity of mass spectrometer, mobile phase solvent, and their information registered in the database section of mass spectrometer A step of detecting peaks of a plurality of additional ions included in detection data obtained by a mass spectrometer by comparing with information on the additional ions expected to be detected under conditions;
(2) A step of obtaining a candidate of a composition formula of an additional ion from a mass-to-charge ratio of the detected additional ions by a precise mass calculation method,
(3) In the obtained composition formula group, a step of comparing the composition formula of the remaining part from which the elements constituting the adduct are removed with a plurality of additional ions,
(4) After comparing, the step of judging the composition formula having a high degree of coincidence as the composition formula of non-addition ions observed in the system;
A method for analyzing a mass spectrum, wherein the composition formula of ions is determined through the four steps. The detection of the peak of the additional ion is performed in at least two types in which the value of the difference in mass to charge ratio between at least two peaks observed in the high mass to charge ratio region may be observed in the measurement system. The mass spectrum analysis method according to claim 1, wherein the mass spectrum analysis method is performed based on whether or not the value of the difference in mass-to-charge ratio between adduct ions coincides. The mass spectrum analysis method according to claim 1, wherein the mass spectrum is generated by a soft ionization method. The method of analyzing a mass spectrum according to claim 3, wherein the soft ionization method is one of API, CI, FAB, MALDI, and FD. 5. The mass spectrum analysis method according to claim 4, wherein the API is either ESI or APCI used as an interface between a liquid chromatography and a mass spectrometer. A mass spectrum analyzer applied to a system in which multiple types of additional ions are observed simultaneously.
(1) An input unit for inputting information on the ionization method, the detection polarity of the mass spectrometer, and the mobile phase solvent,
(2) Ionization method, detection polarity of mass spectrometer, mobile phase solvent, and information on additional ions expected to be detected under those conditions are registered for comparison with the information input from the input unit. Database department,
(3) Based on the comparison between the information input from the input unit and the information registered in the database unit, the peaks of a plurality of additional ions in the detection data obtained by the mass spectrometer are detected and detected. From the mass-to-charge ratio of a plurality of adduct ions, a candidate for a composition formula of the adduct ion is obtained by an accurate mass calculation method, and in the obtained composition formula group, the composition formulas of the remaining part from which the elements constituting the adduct are removed are plural. A comparison unit that compares the addition ions with each other, and after the comparison, determines the composition formula having a high degree of coincidence as the composition formula of the non-addition ions observed in the system, and determines the composition formula of the sample ions,
An apparatus for analyzing a mass spectrum, comprising the following three units. The detection of the peak of the additional ion is performed by detecting at least two types of additional ions in which the value of the difference between the mass and charge ratios observed in the high mass to charge ratio region may be observed in the measurement system. 7. The mass spectrum analyzer according to claim 6, wherein the mass spectrum analyzer is performed based on whether or not the value matches a value of a difference in mass-to-charge ratio. The mass spectrum analyzer according to claim 6 or 7, wherein the mass spectrum is generated by a soft ionization method. 9. The mass spectrum analyzer according to claim 8, wherein the soft ionization method is one of API, CI, FAB, MALDI, and FD. 10. The mass spectrum analyzer according to claim 9, wherein the API is either ESI or APCI used as an interface between a liquid chromatography and a mass spectrometer.

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