CN110320297A - A method of automatically correcting mass spectrum isotope distribution curve - Google Patents
A method of automatically correcting mass spectrum isotope distribution curve Download PDFInfo
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- CN110320297A CN110320297A CN201910602923.7A CN201910602923A CN110320297A CN 110320297 A CN110320297 A CN 110320297A CN 201910602923 A CN201910602923 A CN 201910602923A CN 110320297 A CN110320297 A CN 110320297A
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- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
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- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
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- G01N30/62—Detectors specially adapted therefor
- G01N30/72—Mass spectrometers
- G01N30/7206—Mass spectrometers interfaced to gas chromatograph
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- G—PHYSICS
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- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
- G01N30/62—Detectors specially adapted therefor
- G01N2030/626—Detectors specially adapted therefor calibration, baseline
Abstract
The present invention relates to a kind of methods for automatically correcting isotope distribution, curve (rodlike) source of mass spectral data is in chromatograph-mas spectrometer device, including the optimization to two factors of quality axis and isotope abundance, the accuracy of two factors has decisive meaning to the derivation of target compound molecular formula.The scheme passes through: 1) utilizing local minimum detection (natural) internal standard peak or the start-stop chromatographic regions to school peak；2) in the mass spectrum of each sampled point of fields of interest, the isotope structure of object ion is parsed, calculates the average value of quality axis and isotope abundance；3) error correction function is established by least square polynomial fit, and is applied to the error calculation of ion to be corrected；4) isotopic curves of the corrected value after Gauss box is converted to correction.The scheme can automatically correct the curve or rodlike mode data of different levels MS instrument, can choose and be added without exogenous internal standard compound, only single is needed to test, and it is reliable to correct result.
Description
Technical field
The invention belongs to the MS technical fields of complex system analysis, and in particular, to one kind automatically corrects isotope distribution
The method of curve.
Background technique
Isotope is one of two or more atoms with the same chemical element of same atoms ordinal number, and such as: hydrogen has three
Kind isotope, H protium, D deuterium, isotope that there are many carbon,12C、13C and14C etc. shows various isotope distribution.They
Chemical property it is essentially identical, but mass number is different, thus its MS behavior difference.In order to successfully explain MS, quilt is obtained
The element of test molecule ion or fragment ion composition, i.e. molecular formula, need its quality of precision measurement and isotope abundance.MS instrument
The initial data of generation is isotopic curves mode, but is intuitive and saving storage, is also presented as the rodlike mode of isotope.Molecule
Amount is that each peak axis (or m/z mass number) is calculated by isotope distribution.
Currently, LC or GC-MS combination instrument is widely used in analyzing the complicated analysis system such as Chinese medicine, petroleum, biological sample
In compound, due to not accommodating the standard MS of all compounds in business NIST spectrum library, so in the presence of cannot largely distribute
Chromatographic peak and correlation MS data.In order to identify unknown compound, obtaining its element composition (molecular formula) is precondition.Mesh
Before, have ' seven Golden Rules ' possible candidate molecules formula quantity is reduced using exact mass and isotope abundance.Thus,
In experiment test, need MS instrument that there is accuracy appropriate and precision.Currently, ultrahigh resolution MS instrument can satisfy " standard
The requirement of really measurement ", such as FT-ICR and Orbitrap MS instrument.Since ultrahigh resolution MS instrument is expensive, overwhelming majority experiment
Room such ultrahigh resolution difficult to realize, superior quality accuracy and high sensitivity.Therefore, it is necessary to some resolutions low/high
The data of rate MS instrument carry out recalibration, calculate the element of unknown compound and its fragment ion composition accurately.
Although scientific instrument have achieved huge advance, between the measured value and true value of resolution ratio MS instrument low/high
There are larger or certain deviations, it is sufficient to element composition identification be made to generate mistake.Usually, quality in triple quadrupole bar MS data
Test value accuracy and precision are lower, and isotope abundance is relatively stable；The higher qTOF MS detection of mass accuracy
Device, isotope measure are unstable.Even for the mass value of Orbitrap MS instrument measurement, systematic error is also non-linear deposits
, and mass change is related to peak strength.The existing internal calibrations in laboratory, external calibration method at present, can be in certain journey
Improve these errors on degree, but still remains some problems.Internal calibrations method needs to be added several reagents, the group of external calibration method
Between difference it is big, and the two calibration result is not perfect.Wang Yongdong proposes wave spectrum accuracy concept, and develops
MassWorks software uses PFTBA fragment ion initial data and gross data first, obtains MS peak-shaped function；It again will filtering
Function and the isotope distribution curve for applying to ion to be corrected.However, obtaining filter function is to utilize Fourier's convolution and anti-
Convolution will inevitably introduce error, impact to result.He etc. first by target isotope peak Gauss curve fitting, calculates peak
Axis, then internal calibrations, but early period, Gauss curve fitting data inevitably introduced human factor.For this purpose, we have developed AAID-IC
Algorithm first corrects peak axis, isotope abundance, then corrected value is converted to perfect isotope distribution song by a Gauss box
Line reduces above-mentioned human error.In complicated analysis system, AAID-IC algorithm be can choose certifiedization in sample
Object is closed as natural internal standard, and is added without exogenous internal standard.In addition, we will feel to avoid unnecessary multiplicating from testing
The MS data of different sampled points make full use of in interest spectral range, and uniform, and reduce accidental error, improve indirectly
Calibration result.
Summary of the invention
The purpose of the present invention is breaking through resolution MS instrument bottleneck low/high, one kind is provided and automatically corrects isotope distribution curve
Method.By means of the invention it is possible to effectively improve the accuracy of isotopic peak axis (m/z mass) value and isotope abundance.
The present invention is the method for automatically correcting isotope distribution curve, is not only suitble to curve model MS data, but also be suitble to rodlike
Mode MS data；Not only it is suitble to high-resolution MS data, but also is suitble to low resolution triple quadrupole bar MS data.It relates generally to peak axis (m/z
Quality) two factors of value and isotope abundance optimization.
The method for automatically correcting resolution ratio MS data low/high of the invention is as follows:
(1) data conversion: the initial data of Shimadzu instrument is converted to TXT file, convertible after deleting format text
CDF file is converted to for Matlab file or initial data, is converted to Matlab file；Proteowizard software package is installed
(proteowizard.sourceforge.net), using MSConvert option, can by Waters or Thermo Fisher or
The initial data of Agilent or AB Sciex or Bruker instrument is converted to the formatted files such as mzXML.
(2) blob detection of chromatography dimension:
In LC or GC-MS two-dimensional matrix, longitudinal is that chromatography is tieed up, the chromatography eluant sequence of representative component group；It is laterally MS
Dimension represents the MS data of each chromatography sampled point acquisition.When acquisition mode is set as Raw or Profile, in MS molecule from
Son or fragment ion data are curve form, and data volume obviously increases.
In total ion figure of a traditional Chinese medicine complex system, natural internal standard or target chromatographic peak detecting step are as follows: summit
Be in one section of chromatographic signal local maximum (as long as data point ai it meet: ai-1<ai and ai>ai+1, ai are just office
Portion's maximum value, wherein ai-1 and ai+1 respectively represents the data point of i-1 column and i+1 column)；The estimation of peak width is in the chromatographic peak
Search the local minimum nearest from the ai (unity of thinking as found local maximum, as long as a data point ai-1 in both ends
It meets: ai-1<ai and ai-2>ai-1, ai-1 are just local minimum, and wherein ai-2 represents the data point of i-2 column), thus
The inflow point and elution point of this chromatographic peak are obtained, chromatography peak detection is finally completed.
(3) the overlapping isotope cluster pretreatment of MS dimension: triple quadrupole bar MS data belong to high-resolution data, its same position
Plain peak ([M], [M+1], [M+2]) is inevitably present overlapping phenomenon, will affect next peak axis value and calculates.In Fig. 1 a
GC-MS data, adjacent fragment ion peak [M-1] can also interfere with the peak [M].Therefore, one section of MS number is being intercepted by baseline of minimum value
According to rear, need to pre-process overlapping isotope cluster.Within a test period of an instrument, the half peak height of isotopic peak
The wide ratio with peak width should be fixed value, unrelated with instrumental resolution.In this simple overlapping isotope cluster removing program,
It is measured by the peak width at half height of Fig. 1 b, the available substantially peak width position on baseline；It connects superimposed curves crosspoint and flows into
(out) point；Meanwhile considering that the peak M-1 and the peak M+1 to the cross influence at the peak M, are deducted on primitive curve basis, can be obtained
The peak M of removing.
The data higher for resolution ratio, such as Radix Glycyrrhizae LC-MS data, directly the interception peak M.
(4) each sampled point isotopic peak axis calculating and error correction function: systematic error and random error coexist in reality
In MS data, it is difficult to completely remove.For the latter, severe jamming is analyzed signal and mass value is caused to fall in actual measurement quality by noise
The two sides of mean value.Before establishing internal calibration function, the 2-D data start-stop point of one section of proper strength is selected, it is automatic to obtain often
The curve model MS data of one sampled point, and the isotopic peak axis of object ion is calculated, take mean value；Herein, GC-MS,
LC-MS and LC-qTOF-MS intercepts mass spectrometric data section respectively with 5amu, 5amu of monoisotopic peak axis and 10~12amu range.
For removing or the direct monoisotopic peak that intercepts, axis value is by formula (1) calculating:
Wherein, y0It is the column vector comprising curve mass spectrometric data, T represents transposition, m0Correspond to the matter of measurement isotope cluster
The column vector of axis is measured, l is length and m0With y0The same unit column vector, mcIt is the central value being calculated.
For the mass data that the high-resolution MS instrument such as LC-qTOF-MS generates, curvilinear mold can be obtained through the above way
The quality axis of monoisotopic peak or other isotopic peaks under formula.It, can be rodlike with full scan in order to reduce operation memory and time
Mode data directly reads single isotopic mass or other isotopic masses (the maximum experiment m/z value of response).
After calculating or reading (natural) interior target isotopic peak axis or m/z value, each sampled point is uniformed, instrument error school
Positive function (2):
M=f (mc)
M is Theoretical Mass, mcIt is axis value (curve model) or the mistake for testing m/z value (rodlike mode) and corresponding theory value
Difference, the two obtain functional relation by least square polynomial fit.In next correction course, it can be established from this
Functional relation obtain test m/z value corresponding error amount.
(5) in AAID-IC algorithm, isotopic peak [M+1] or [M the isotope abundance optimization of each sampled point MS dimension: are read
+ 2] or [M+3] abundance local maximum, a series of local maximums of different sampled points are uniformed, by formula (3) and theory
It is worth fit linear relationship:
X=f (xc)
X is theoretical isotope abundance, xcIt is the isotope abundance local maximum after homogenization.It was corrected next
Cheng Zhong can obtain the isotope abundance after correction from this established functional relation.
(6) a Gauss box is constructed to the corrected value that (4) and (5) obtain, can be obtained isotope distribution calibration curve.
Basic Gaussian function formula (4) is as follows:
Parameter A, xc and S are respectively the peak value, peak position and half width information of Gaussian curve in formula, and ans is final obtains
The Gaussian curve arrived, S control the FWHM of Gaussian curve.Based on (4) formula, a Gauss box can be constructed.From (3) and
(4) value obtained in is calculated by Gauss box, it will be able to be obtained one and is similar to theoretical isotope distribution curve.To,
Us can be made more intuitively to compare isotope distribution calibration curve and theoretical curve.
Compared to the prior art, AAID-IC provided by the invention has the advantages that
1, with true radix bupleuri essential oil GC-MS data, licorice LC-MS data instance, AAID-IC can preferably drop
The systematic error and accidental error of object ion isotope distribution curve under harmonic curve mode.
2, the drawbacks such as memory is big are accounted for reduce high-resolution MS mass data, AAID-IC reads MS under rodlike mode, obtains mesh
The maximum m/z value at ion isotopes peak is marked, isotope abundance is calculated, carries out correction, and further with the true of bupleurum total saponin
Real LC-qTOF-MS data verification this method, accuracy are all improved.
The AAID-IC algorithm invented herein can correct curve/rodlike mode data of different MS instruments, have reliable, real
With with widespread popularity.
Detailed description of the invention
Fig. 1 a bupleurum Chinense volatile oil GC-MS instrument measurement result
The relationship of Fig. 1 b acquisition peak width at half height and peak width
The GC-MS instrument measurement result of Fig. 2 PFTBA
The quality error correction relationship of Fig. 3 a PFTBA fragment ion
The correction relationship of isotope (M+1) abundance of Fig. 3 b PFTBA fragment ion
The fragment ion correction front and back and the comparison with theoretical isotopic curves that m/z is 131 in Fig. 3 c PFTBA
The GC-MS instrument measurement result of Fig. 4 Bupleurum Chinese volatile oil
The quality error correction relationship of Fig. 5 a Bupleurum Chinese volatile oil fragment ion
The correction relationship of isotope (M+1) abundance of Fig. 5 b Bupleurum Chinese volatile oil fragment ion
The fragment ion correction front and back and the comparison with theoretical isotopic curves that m/z is 138 in Fig. 6 a Bupleurum Chinese volatile oil
The fragment ion correction front and back and the comparison with theoretical isotopic curves that m/z is 150 in Fig. 6 b Bupleurum Chinese volatile oil
The LC-MS instrument measurement result of Fig. 7 licorice
The quality error correction relationship of Fig. 8 a licorice fragment ion
The correction relationship of isotope (M+1) abundance of Fig. 8 b licorice fragment ion
The correction relationship of isotope (M+2) abundance of Fig. 8 c licorice fragment ion
The fragment ion correction front and back and the comparison with theoretical isotopic curves that m/z is 839 in Fig. 9 licorice
The LC-qTOF-MS instrument test knot of each reference substance (above) of Figure 10 saikoside, total saponins from radix bupleuri extract (following figure)
Fruit
Quality error correction relationship of Figure 11 a saikoside fragment ion under rodlike mode
The correction relationship of isotope (M+1) abundance under the rodlike mode of Figure 11 b saikoside fragment ion
The correction relationship of isotope (M+2) abundance under the rodlike mode of Figure 11 c saikoside fragment ion
The correction relationship of isotope (M+3) abundance under the rodlike mode of Figure 11 d saikoside fragment ion
In Figure 12 saikoside m/z be 973 the rodlike mode of fragment ion under correction front and back and with theoretical isotopic curves
Comparison
Figure 13 automatically corrects the flow chart of mass spectrum isotope distribution curve method
Specific embodiment
Present invention will be further explained below with reference to specific examples.It should be understood that these embodiments are merely to illustrate the present invention
Rather than it limits the scope of the invention.In the following examples, the experimental methods for specific conditions are not specified, usually according to conventional strip
Part or according to the normal condition proposed by manufacturer.Unless otherwise stated, otherwise all percentage, ratio, ratio or number is pressed
Poidometer.
Unless otherwise defined, it anticipates known to all professional and scientific terms as used herein and one skilled in the art
Justice is identical.In addition, any method similar to or equal to what is recorded and material can be applied to the method for the present invention.Wen Zhong
The preferred implement methods and materials are for illustrative purposes only.
1 perfluorotributylamine GC-MS instrument measurement result of embodiment and AAID-IC are corrected
The GC Elevated Temperature Conditions of PFTBA are as follows: 40 DEG C of holding 6min, with 3 DEG C of min-1Rise to 70 DEG C.Mass spectrograph is in electron bombardment
It works under mode, scanning range is 33~550amu, ionization energy 70eV.Level four bars, preceding injection port, ion source and Aux-z temperature
Degree is kept at 150 DEG C, 280 DEG C, 230 DEG C and 280 DEG C.In chromatography dimension, mass spectrogram such as Fig. 2 of a certain sampled point of PFTBA
(a) and shown in Fig. 2 (b), wherein shadow region is area-of-interest.The actual measurement mean value of each fragment ion of PFTBA, accuracy can only
Reach 1amu, mass shift is both greater than 60mDa, and this data are difficult to the element composition of unknown ion.Researcher selects
The fragment ion peak that m/z is 69,100,119,169,219 and 264 calculates peak axis, homogenization and instrument error correction function.From
Fig. 3 (a) illustrates that the correction function relationship is good, it is emerging can to feed back to sense it can be concluded that error amount and m/z size presentation arcuation trend
The ion to be corrected of interest.In addition, also there is biggish errors in measured data for isotope abundance value.Fig. 3 (b) is PFTBA
In multiple actual measurement isotope abundances and theoretical abundance linear functional relations.
Object ion test value can be preferably corrected with AAID-IC method.Fig. 3 (c) black dotted lines are that m/z is 131Da
Primary isotope cluster, which does not have known definable peak shape, and peak axis value error is larger.Use above-mentioned correction function
Afterwards, axis value in peak differs only -1.6mDa with theoretical value, and isotope (M+1) abundance is 3.2622, differs with theoretical value and is only
0.0192.As shown in Fig. 3 (c), the correction isotopic peak cluster (black) and theoretical curve (ash) difference obtained by Gauss box is non-
It is often small, the reliability and accuracy of AAID-IC method is intuitively illustrated.To sum up, AAID-IC algorithm can greatly improve three
The mass accuracy for the low-resolution data that weight level four bars mass spectrum obtains under curve model.But from each fragment ion mean value
Standard deviation finds out that the intensity at peak is lower, more the influence vulnerable to baseline and noise.Therefore, ion signal intensity interested is improved
It is most important to calibration result.
Embodiment 2 is corrected based on the bupleurum Chinense volatile oil GC-MS data AAID-IC of natural internal standard compound
Bupleurum Chinense volatile oil: radix bupleuri is carried out steam extraction 4h, obtained by the extracting method described according to Chinese Pharmacopoeia 2010 editions
To volatile oil be sealed in brown vial, and analyze immediately.
GC-MS analysis: the triple level four bars MS instrument (Agilent, the U.S.) of 6890 GC instrument -5973；Chromatographic column is HP-5MS
(30m × 0.25mm i.d., film thickness 0.25m, Agilent)；Temperature programming: 1) 40 DEG C holding 6min, with 3 DEG C of min-1It rises to
90 DEG C, then with 1 DEG C of min-1Rate rise to 140 DEG C, finally rise to 280 DEG C with 10 DEG C of min-1, keep 3min；MS instrument
It works under electron-impact mode, scanning range is 33~550amu, ionization energy 70eV.Level four bars, preceding injection port, ion source
150 DEG C, 280 DEG C, 230 DEG C and 280 DEG C are kept at Aux-z temperature.The separation sample introduction of radix bupleuri be 1 μ L, segregation ratio 1:
5, it is analyzed respectively under full scan and original scan mode.
AAID-IC algorithm parameter:
1, the original CDF formatted file that the triple level four bars MS instrument of 6890 GC instrument of input -5973 obtain.Such as: dd='
HE4.CDF'；
2, the time range for the chromatographic peak that input needs to intercept.Such as: ' xt=1.97；Yt=2.05 '；
3, input needs the mass charge ratio range intercepted.Such as: ' xx=129；Yy=134 '；Generally 5amu
4, what is returned in test_four is the mass value after correction, and the parameter for needing to input includes: building error correction
Chromatographic data the time range x_z and x_y of relationship, chromatographic time the range xt=and yt of ion to be corrected, the matter for needing to intercept
Lotus is than range xx and yy, CDF file dd=' HE4.CDF '.
5, what test_tws was returned is the isotope abundance after correction, and the parameter for needing to input includes: ion to be corrected
Chromatographic time range xt=and yt, the mass charge ratio range xx and yy for needing to intercept, CDF file dd=' HE4.CDF '.
As shown in figure 4, the total ion figure of the GC-MS of Bupleurum Chinese volatile oil implies traditional medicine volatile oil complicated component.According to mass spectrum
The mass spectrometric data of similarity and retention index, most chromatographic peaks can be annotated accurately.But NIST database missing is very
The control mass spectrum of more plant metabolites, similarity search can not be matched to " true " compound.Therefore, uncommon plant metabolism
The molecular ion and fragment ion of object become the important evidence of authenticating compound.AAID-IC method can preferably correct isotope
Cluster, the exact mass and isotope abundance of acquisition are most important to the element composition confirmation of molecular ion or fragment ion.
In AAID-IC program, construct suitable error correction function and be important a step, need a certain range m/z and
Sufficient amount of internal standard data.However, internal standard is not easy to obtain, and it is easy to interfere tested data.Body is analyzed in middle prodrug complex
In system, largely can certified compound may be used as natural internal standard, instrument error correction function has very useful meaning
Justice.Such as Fig. 1 a, select Undecan in bupleurum Chinense volatile oil GC-MS data fragment ion m/z 43,57,71,85,99,113,
156, it is used for instrument error correction function.By enlarged drawing as can be seen that m/z be 71m Da the peak fragment [M] not only by
The influence at the peak [M+1], the also interference by the peak [M-1], this is for calculating monoisotopic peak axis value using formula (1), it will produces
Raw greatly interference.Therefore, the overlapping isotope cluster processing method mentioned using (2) is removed, and effect is preferable.As shown in table 1,
The original quality error of each fragment ion is all larger than 90mDa, and the fluctuation of isotope abundance is also very big.Fig. 5 a and Fig. 5 b distinguish table
Show the quality error correction function relationship and isotope abundance functional relation of some ions in bupleurum Chinense volatile oil GC-MS data.From
It can find out in Fig. 5 a, between m/z 43-160, error amount shows the downward trend similar with PFTBA fragment ion.But
The correction function of PFTBA is not suitable for bupleurum Chinense volatile oil GC-MS data, can only use internal calibrations method.In Fig. 5 b, radix bupleuri is waved
There is also notable differences for the ion isotopes abundance of different chromatography sampled points in hair oil GC-MS data, are corrected by AAID-IC,
More accurately isotope abundance can be obtained.
Then Furan, 2-pentyl and 2,4-Decadienal are used, the molecular ion peak of (E, E)-is for verifying AAID-
The reliability of IC algorithm.Furan, 2-pentyl-, Theoretical molecular quality are 138.0898, and theoretical isotope abundance is 9.93；
2,4-Decadienal, (E, E)-, Theoretical molecular quality is 152.1201, and theoretical isotope abundance is 11.04.In Fig. 6 a and
In Fig. 6 b, the original isotope distribution cluster of two kinds of ions receives the interference of noise, and not only Mass accuracy is low, and peak shape
Distortion.And pass through the ion isotopes cluster after the correction of ASA-IC algorithm, obtain preferable correction.Table 2 is two in radix bupleuri
Quality error after fragment ion mass spectrometric data is corrected, obtained result is within the scope of 14mDa；Obtained isotope abundance
Very little is also differed with theoretical isotope.This illustrates the dependable with function of this algorithm.
The AAID-IC of the true GCMS data of 2 Bupleurum Chinese volatile oil of table corrects result
Embodiment 3 is corrected based on the licorice LC-MS data AAID-IC of natural internal standard compound
Licorice: 1g Radix Glycyrrhizae is extracted three times using 65% ethyl alcohol, adjusts concentration.
LC-20A Shimadzu chromatograph (Japan)；Mobile phase is 0.2% formic acid (A) and acetonitrile (B), flow velocity 0.2mL/
Min, gradient condition: 0-1min 10%B, 1-33min 10%-45%, 33-50min 45%-90%, 50-55min 90%；
Chromatographic column: Kromasil C18 (2.1 × 150mm × 5 μm).
2000 mass spectrograph (U.S.) of AB Q-trap API；Acquire data under positive ion mode, scan pattern Profile,
M/z range: 100-1250Da, collection period 2sec.
Algorithm parameter:
1, the original XML format text that input 2000 mass spectrograph (U.S.) of LC-20A chromatograph-AB Q-trap API obtains
Part.Such as: dd=' 02.mzXML；
2, the time range for the chromatographic peak that input needs to intercept.Such as: ' xt=15.54；Yt=15.78 '；
3, input needs the m/z range intercepted.Such as: ' xx=838；Yy=843 '；Generally 5amu
4, what is returned in test_four is the mass value after correction, and the parameter for needing to input includes: building error correction
Chromatographic data the time range x_z and x_y of relationship, the chromatographic time range xt=and yt of ion to be corrected, the m/z for needing to intercept
Range xx and yy, XML file dd=' 02.mzXML；.
5, that test_tws is returned is the isotope abundance ab after correction, and the isotope abundance c before correcting needs defeated
The parameter entered includes: chromatographic time the range xt=and yt of ion to be corrected, m/z the range xx and yy for needing to intercept, XML file
Dd=' 02.mzXML '.
Test results are shown in figure 7 by the LC-MS of licorice, Liquiritin and Glycyrrhizic acid has made
It is matched and is identified with reference substance.It is related in Liquiritin to Glycyrrhizic acid mass spectrum in AAID-IC correction course
Ion be used to construct correction function, their single isotopic mass mean value and isotope abundance mean value is shown in Table 3 and table 4 respectively.
From table 3 it is observed that each chromatography sampled point is both greater than 320mDa by the quality axis error that formula (1) calculates, pass through structure
Build error correction function, it is possible to reduce systematic error.It is obtained from table 4, isotope abundance is by noise or other disturbing factors
It influences, difference is obvious.Fig. 8 a is the error correction function of building, and the relationship of error and m/z are in first rising becoming of declining afterwards
Gesture.Fig. 8 b and Fig. 8 c are the isotope abundance relationship of M+1, M+2 building respectively, show a kind of linear relationship.
For constructing the actual measurement quality mean value of the fragment ion of quality error correction relationship under 3 LC-MS curve model of table
Error correction function is used to correct for Licoricesaponin G2 and Licoricesaponin C2, obtained list
Isotopic peak axis calibration value and isotope abundance calibration value are shown in Table 5 and table 6 respectively.In table 5, it can be seen that biggish system is missed
Difference is present in LC-MS initial data, and after the correction of AAID-IC algorithm, error < 20mDa.In table 6, isotopic peak cluster
M+1 and M+2 Abundances by AAID-IC algorithm correction after, also obtained very big improvement.Fig. 9 is that the ion of m/z 839 is broken
The comparison of isotope cluster and theoretical curve of the sheet data by AAID-IC processing, the two are coincide in the extreme, this illustrates AAID-IC
The practicability and stability of algorithm.
Exact mass after the correction of 5 licorice fragment ion mass spectrometric data of table
Isotope abundance after the correction of 6 Radix Glycyrrhizae fragment ion mass spectrometric data of table
Embodiment 4 is corrected based on the bupleurum total saponin LC-qTOF-MS data AAID-IC of natural internal standard compound
Bupleurum total saponin: 0.2g radix bupleuri 85% methanol ultrasonic extraction 40min of 5ml adjusts concentration sample introduction.
Agilent chromatograph (U.S.): mobile phase is water (A) and acetonitrile (B), contains 0.1% (v/v) formic acid, flow velocity
0.3mL/min, gradient condition: 0-5min 10%B, 5-25min 10%-35%, 25-28min 35%-55%, 28-30min
55%-85%, 30-31min 85%-100%, 31-40min 10%；Chromatographic column: the XAqua C18 (μ of 2.1 × 150mm × 5
m)。
6520 qTOF mass spectrograph (U.S.) of Agilent；Data, scan pattern Profile, m/ are acquired under negative ion mode
Z range: 100-1700Da, collection period 2sec.
Algorithm parameter:
1, the original XML format file that input 6520 qTOF mass spectrograph (U.S.) of LC chromatograph-Agilent obtains.Example
Such as: dd=' ch8.mzXML；
2, the time range for the chromatographic peak that input needs to intercept.Such as: ' xt=9.84；Yt=9.93 '；
3, input needs the m/z range intercepted.Such as: ' xx=989；Yy=993 '；General range is 10~12amu
4, what is returned in test_four is the mass value after correction, and the parameter for needing to input includes: building error correction
Chromatographic data the time range x_z and x_y of relationship, the chromatographic time range xt=and yt of ion to be corrected, the m/z for needing to intercept
Range xx and yy, XML file dd=' ch8.mzXML；.
5, that test_tws is returned is the isotope abundance ab after correction, and the isotope abundance c before correcting needs defeated
The parameter entered includes: chromatographic time the range xt=and yt of ion to be corrected, m/z the range xx and yy for needing to intercept, XML file
Dd=' ch8.mzXML '.
AAID-IC method is equally applicable to curve/rodlike mode data of correction LC-qTOF-MS, for arithmetic speed and deposits
Reason is stored up, rodlike mode data is selected.The LC- of each reference substance (above) of saikoside, total saponins from radix bupleuri extract (following figure)
Total ion figure of qTOF-MS, as shown in Figure 10.We take the m/z's 779,825,893,971 and 1559 of authenticating compound
Fragment ion integrates ion building correction function, including [M-H]-、[M+HCOO]-、[M+CF3COO]-、[2M-H]-；Optionally take
Prosaikogenin A peak m/z 663 [M+HCOO]-With 1235 [2M-H]-.The quality mean value and M+1, M+2 of this 7 ions
It is shown in Table 7 and table 8 respectively with the isotope abundance mean value of M+3.As can be seen from the table, the m/z under the rodlike mode of LC-qTOF-MS
It is worth more stable, but each isotope abundance diversity ratio is larger.Figure 11 a is the quality error functional relation of building, under presenting first
The trend risen after drop.Figure 11 b, Figure 11 c and Figure 11 d are the isotope abundance function of M+1, M+2 and M+3 building respectively, are in
Reveal a kind of linear relationship.
For constructing the actual measurement quality of the fragment ion of quality error correction relationship under the rodlike mode of 7 LC-qTOF-MS of table
Mean value
It is 10.55min left that quality error function obtained above and isotope abundance relationship, which are used for corrected retention time,
The Saikosaponin F's and 13.65min of right Hydroxyl Saikosaponin D, 12.40min or so or so
Saikosaponin b3.By the correction of AAID-IC algorithm, mass calibration result and isotope abundance calibration result are shown in respectively
Table 9 and table 10, accuracy is had been further upgraded.As shown in figure 12, the object ion of m/z 973 is through AAID-IC algorithm
After correction, the comparison of isotope cluster and theory distribution curve.The result illustrates the practicability of AAID-IC algorithm.
The foregoing is merely illustrative of the preferred embodiments of the present invention, the substantial technological content model being not intended to limit the invention
It encloses, substantial technological content of the invention is broadly defined in the scope of the claims of application, any technology that other people complete
Entity or method also or a kind of equivalent change, will if identical with defined in the scope of the claims of application
It is considered as being covered by among the scope of the claims.
Exact mass after the correction of 9 saikoside fragment ion mass spectrometric data of table
Claims (5)
1. a kind of method for automatically correcting isotope distribution curve, it is characterised in that:
Curve (rodlike) mode data is combined instrument from LC or GC-MS (TOF MS), including to peak axis (m/z
Mass number) and two factors of isotope abundance optimization, accurate derivation of the numerical value of two factors to target compound molecular formula
With decisive meaning.
Aligning step is as follows:
(1) data conversion: by Shimadzu or Waters or Thermo Fisher or Agilent or AB Sciex or Bruker
The initial data of instrument is converted to Matlab or mzXML formatted file；
(2) natural internal standard identification: LC-MS is combined instrument and is confirmed using control compound retention time, and GC-MS is combined instrument and uses
NIST/WILLY mass spectrum storehouse matching and the confirmation of NIST retention index library；
(3) chromatographic dimension blob detection: positioning (natural) internal standard peak detects peak start-stop point using local minimum, and locking is suitable strong
The target MS quasi-molecular ions of each sampled point in chromatography domain is spent, and is uniformly distributed the ion m/z mass number chosen in a certain range；
(4) isotopic peak cluster pre-processes: the data acquisition of low resolution triple quadrupole bar MS is curve model, to each sampled point MS
[M] of dimension, [M+1], [M+2] overlap peak are simply stripped off.
(5) peak axis, isotope abundance calculate: curve model MS data, automatic to calculate peak axis, isotope abundance；
(6) ion m/z mass and isotope abundance are read: rodlike mode MS data, automatic to read maximum intensity m/z mass number,
And calculate isotope abundance；
(7) numerical value is uniform: the calculated value of each sampled point under (5) or (6) item being uniformed, and is statisticallyd analyze；
(8) by each m/z ion of natural internal standard, error correction function correction function: is established by least square polynomial fit；
(9) it corrects: applied to the peak axis of ion to be corrected, isotope abundance；
(10) the isotope distribution curve after correcting: corrected value is handled by Gauss box, the isotope distribution after obtaining correction
Curve.
2. the method according to claim 1 for automatically correcting isotope distribution curve, which is characterized in that acquisition and optimization mesh
The MS information of each sampled point in chromatography domain is marked, correction is completed in primary test.
3. the natural interior of sample itself can be selected in the method according to claim 1 for automatically correcting isotope distribution curve
Object is marked, exogenous compounds can also be added.
4. the method according to claim 1 for automatically correcting isotope distribution curve can correct the curve of different MS instruments
Or rodlike mode data.
5. the method eligible result described in claim 1 for automatically correcting isotope distribution curve, can be used for: Chinese medicine, petroleum and
The exact mass and isotope ratio measurement of the non-targeted chromatography-MS test of the complex systems such as biological sample, accurately calculate unknownization
Close the molecular formula (element composition) of object.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022063816A1 (en) | 2020-09-23 | 2022-03-31 | Roche Diagnostics Gmbh | Computer-implemented method for detecting at least one interference and/or at least one artefact in at least one chromatogram |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1851573A (en) * | 2006-05-12 | 2006-10-25 | 浙江中控软件技术有限公司 | Modelling method for predicating impurity component concentration for dimethyl benzene oxidation process |
| CN1898674A (en) * | 2003-10-20 | 2007-01-17 | 瑟诺生物科学有限责任公司 | Methods for calibrating mass spectrometry (ms) and other instrument systems and for processing ms and other data |
| US20070023633A1 (en) * | 2005-05-29 | 2007-02-01 | Yongdong Wang | Application of comprehensive calibration to mass spectral peak analysis and molecular screening |
| US20080052011A1 (en) * | 2006-07-29 | 2008-02-28 | Yongdong Wang | Determination of chemical composition and isotope distribution with mass spectrometry |
| US20090302213A1 (en) * | 2005-10-28 | 2009-12-10 | Donald Kuehl | Interactive method for identifying ions from mass spectral data |
| CN104237364A (en) * | 2013-06-07 | 2014-12-24 | 塞莫费雪科学（不来梅）有限公司 | Isotopic pattern recognization |
| CN105842330A (en) * | 2015-09-09 | 2016-08-10 | 张华俊 | Mass spectrum detection and analysis method |
| CN108030850A (en) * | 2018-01-29 | 2018-05-15 | 湘潭大学 | A kind of supercritical CO2The method for extracting active ingredient in bupleurum powder for relieving liver-qi |
| CN108519453A (en) * | 2018-04-11 | 2018-09-11 | 广东出入境检验检疫局检验检疫技术中心 | A kind of assay method of 19 kinds of benzimidazoles residues residual quantities based on isotopic dilution-editable multiple-reaction monitoring pattern |
| CN109390036A (en) * | 2018-10-31 | 2019-02-26 | 湘潭大学 | A method of excavating selection microalgae grease anabolism marker |
| CN109738532A (en) * | 2018-12-31 | 2019-05-10 | 复旦大学 | A method of automatically parsing stable isotope labeling sugar chain quantitative mass spectral data |
-
2019
- 2019-07-04 CN CN201910602923.7A patent/CN110320297A/en active Pending
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1898674A (en) * | 2003-10-20 | 2007-01-17 | 瑟诺生物科学有限责任公司 | Methods for calibrating mass spectrometry (ms) and other instrument systems and for processing ms and other data |
| US20070023633A1 (en) * | 2005-05-29 | 2007-02-01 | Yongdong Wang | Application of comprehensive calibration to mass spectral peak analysis and molecular screening |
| US20090302213A1 (en) * | 2005-10-28 | 2009-12-10 | Donald Kuehl | Interactive method for identifying ions from mass spectral data |
| CN1851573A (en) * | 2006-05-12 | 2006-10-25 | 浙江中控软件技术有限公司 | Modelling method for predicating impurity component concentration for dimethyl benzene oxidation process |
| US20080052011A1 (en) * | 2006-07-29 | 2008-02-28 | Yongdong Wang | Determination of chemical composition and isotope distribution with mass spectrometry |
| CN104237364A (en) * | 2013-06-07 | 2014-12-24 | 塞莫费雪科学（不来梅）有限公司 | Isotopic pattern recognization |
| CN105842330A (en) * | 2015-09-09 | 2016-08-10 | 张华俊 | Mass spectrum detection and analysis method |
| CN108030850A (en) * | 2018-01-29 | 2018-05-15 | 湘潭大学 | A kind of supercritical CO2The method for extracting active ingredient in bupleurum powder for relieving liver-qi |
| CN108519453A (en) * | 2018-04-11 | 2018-09-11 | 广东出入境检验检疫局检验检疫技术中心 | A kind of assay method of 19 kinds of benzimidazoles residues residual quantities based on isotopic dilution-editable multiple-reaction monitoring pattern |
| CN109390036A (en) * | 2018-10-31 | 2019-02-26 | 湘潭大学 | A method of excavating selection microalgae grease anabolism marker |
| CN109738532A (en) * | 2018-12-31 | 2019-05-10 | 复旦大学 | A method of automatically parsing stable isotope labeling sugar chain quantitative mass spectral data |
Non-Patent Citations (3)
| Title |
|---|
| DITTWALD,P 等: "BRAIN: A Universal Tool for High-Throughput Calculations of the Isotopic Distribution for Mass Spectrometry", 《ANALYTICAL CHEMISTRY》 * |
| MILLARD，P 等: "IsoCor: correcting MS data in isotope labeling experiments", 《BIOINFORMATICS》 * |
| 刘雪梅 等: "痕量铅的高精度同位素测量中分馏效应校正技术研究", 《质谱学报》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022063816A1 (en) | 2020-09-23 | 2022-03-31 | Roche Diagnostics Gmbh | Computer-implemented method for detecting at least one interference and/or at least one artefact in at least one chromatogram |
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