Shimadzu Corporation

Yoshikatsu Umemura

Yoshitake Yamamoto

Tetsuya Kageyama

Shinichi Yamaguchi

Akira Noda

Hideki Yamamoto

Masahiro Ikegami

Kazuma Maeda

Tomoyuki Oshiro

Hiroyuki Yasuda

Kazuo Yamauchi

Koji Tanaka

To acquire a mass spectrum for a wide mass range, a normal analysis execution controlling unit controls components to repeatedly perform measurement while changing setting m/z by a predetermined m/z at a time, and a mass spectrum summarizing processing unit summarizes data pieces each obtained by each time of measurement to generate the mass spectrum. Radio-frequency voltage applied to an ion guide and the like is changed based on the setting m/z. The radio-frequency voltage for the setting m/z is determined using a table in which a relationship between a position on an axis between upper and lower limits of the mass range and the radio-frequency voltage is substantially the same regardless of the mass range.

Time-of-flight mass spectrometer

For every acquisition of a set of mass spectrum data, a mass calibrator (determines the amount of mass discrepancy using the appearance position of a peak originating from an internal standard substance having a known m/z value, and performs a process for correcting the mass discrepancy. A mass calibration information collector (collects the amount of mass discrepancy or mass correction quantity for each set of mass spectrum data. After the completion of the measurement, a three-dimensional display information creator creates a three-dimensional graph showing the large number of collected mass correction quantities plotted in a three-dimensional space in which the retention time in a primary column and the retention time in a secondary column in a comprehensive two-dimensional LC unit are represented by two mutually orthogonal axes while the mass correction quantity is represented by the axis orthogonal to those two axes.

Analyzing apparatus

For a sample containing a target component, a product-ion scan measurement in which the m/z value of a known ion originating from the compound is designated as a precursor ion is performed in a measurement unit () to acquire profile spectrum data. A peak detector () in a data processing unit (A) detects peaks on the profile spectrum. For each detected peak, a product-ion m/z-value acquirer () acquires an m/z value corresponding to the maximum intensity as the m/z value of a product ion. A pseudo MRM measurement data extractor () adopts the m/z value of the precursor ion and that of the product ion as an MRM transition, extracts the maximum intensity of the peak originating from the product ion as the signal intensity value on that MRM transition, and stores these data as pseudo MRM measurement data in a memory section (). Thus, quantitative information which reflects the concentration of the target compound can be obtained by a simple product-ion scan measurement without performing an MRM measurement.

Mass spectrometer

Nonuse-indication information can be set for each peak on a mass spectrum collected in a compound database, as attribute information, the nonuse-indication information allowing the selection of whether to be used in a database search. For example, nonuse-indication information is set in advance to a noise peak mixed in actual measurement, an impurity-originated peak, and the like. In identifying a compound, when nonuse-indication information is read from the database for a database search together with a mass spectrum, an unnecessary information deleting section transmits a mass spectrum from which a peak set with the nonuse-indication information is deleted, to a compound candidate extracting section and a scoring section. Therefore, a peak set with the nonuse-indication information is ignored in, for example, calculating the score of a compound candidate, which allows a score with a high accuracy to be calculated, resulting in an improved identification accuracy.

Mass-spectrometry-data processing system

A mass spectrometry data processing apparatus having a function of displaying a plurality of MSspectra in an arranged manner is allowed to display these MSspectra in a state where a user can easily grasp presence or absence of a common neutral loss. A mass spectrometry data processing apparatusthat displays, on a display screen, an MSspectrum resulting from mass spectrometric analysis of n&#x2212;1 stage dissociation, where n is integer of two or more, of an ion, includes: a precursor ion identifying sectionconfigured to identify, for each of a plurality of MSspectra, a mass-to-charge ratios m/z of a precursor ion from which the MSspectra are obtained; and a spectrum aligning sectionconfigure to display the MSspectra on the display screen in a vertically arranged manner such that positions of the mass-to-charge ratios m/z of the respective precursor ions are located at a same horizontal position of the display screen.

Mass spectrometry data processing apparatus

When, in performing MS/MS analysis on a multivalent ion originated from a target component, an analyzing operator inputs at least two values of a mass value mof an eliminated fragment, a valence zof the eliminated fragment, a valence zof a precursor ion and a valence zof a product ion by an inputting unit, a valence calculating unit calculates an uninput valence zor zbased on the relation, z=z+z. Upon the start of the MS/MS analysis, a precursor ion m/z setting unit sets m/z=Mof an ion that passes through a front-stage quadrupole mass filter , and a passed product ion m/z calculating unit calculates m/z=Mof the product ion that passes through a rear-stage quadrupole mass filter by applying M, m, zand zabove to the relational expression, M=(M&#xd7;z&#x2212;m)/z.

MS/MS mass spectrometric method and MS/MS mass spectrometer

The present invention aims at providing a method and apparatus for analyzing a mass spectrum on which multivalent ion peaks originating from a target compound appear, and calculating the mass of the target compound. First, each peak on the mass spectrum is analyzed to detect isotopic clusters, and the valence and the representative point (m/z value) of each isotopic cluster are obtained (Sthrough S). Since the range of the m/z value of the component which is added to or desorbed from the compound is limited, by using this factor, the isotopic clusters originating from the same compound are deduced. By combining the deduced isotopic clusters, the candidates for the m/z value of the added/desorbed component are deduced (S). Among the plurality of selected candidates, clearly abnormal candidates are eliminated by using a plurality of conditions such as the degree of distribution of the m/z values and the similarity of the relative intensities of the representative points of the isotopic clusters (Sthrough S). The candidate having the smallest distribution of m/z values or the candidate having the highest similarity of the relative intensities of the representative points is finally selected. After the m/z value of the added/desorbed component is determined, the mass of the compound is calculated (Sthrough S).

Mass analysis data analyzing method and mass analysis data analyzing apparatus

In a mass analysis data analyzing apparatus, centroid data is used as mass spectrum data to be analyzed. First, peaks on the centroid data are specified in order of intensity as a standard peak for identifying an isotopic cluster. The isotopic cluster is detected by comparing an emerging pattern of peaks near the standard peak and an emerging pattern of peaks of an expected isotopic cluster in the case where each valence is assumed. The valence of the determined isotopic cluster is set as the valence of the peaks belonging to the isotopic cluster, and the peak at the forefront of cluster is selected as a monoisotopic peak. With such a mass analysis data analyzing apparatus, it is possible to determine the valence of each peak and identify the monoisotopic peak in a mass spectrum.

Mass analysis data analyzing apparatus and program thereof

Intensity data of the signals produced by an ion detector are sequentially stored in a data processor, with each piece of intensity data being associated with time t required for each of the various ions ejected from an ion trap to fly through a time-of-flight space and reach the ion detector. The data obtained within a time range Tcorresponding to a measurement mass range are extracted as profile data. The data obtained within either a time range Tbefore the arrival of an ion having the smallest m/z value or a time range Tafter the arrival of an ion having the largest m/z value are extracted as noise component data. Various kinds of noise information such as the noise level or standard deviation are calculated from the noise component data. Based on this noise information, a noise component is removed from the profile data. For every mass scan cycle, the noise component data and profile data are almost simultaneously obtained. Therefore, even if the electrical noise from the ion detector changes with time, the noise can be properly removed with little influence from that change of the noise.

Method for processing mass analysis data and mass spectrometer

The analyst previously enters the mass of a fragment that desorbs in the first dissociation with other analysis conditions, as the precursor ion selection reference for the second dissociation through the input unit. When the automatic analysis is started, the controller unitsequentially performs the MSanalysis, MSanalysis and MSanalysis. In the course of these analyses, the data processing unitdetermines the valence of each ion species corresponding to the peaks appearing in the mass spectrum obtained by the MSanalysis. In addition, after the MSanalysis, the data processing unitsearches for the ion species in conformity with the selection reference in consideration of the determined valence, among the ion species corresponding to the peaks appearing in the mass spectrum by the MSanalysis. The selected ion is determined as the precursor ion for the second dissociation in the MSanalysis. In this manner, regardless of the valence of the target ion, the precursor ions to be selected and dissociated in each stage of the MSanalysis are automatically selected according to the mass of the fragment desorbed in the dissociation in the previous stage. Therefore, the analytical efficiency is improved and the highly accurate chemical structure information can be obtained.

The present invention provides a chromatograph/mass spectrometer capable of producing a composite chromatogram from plural chromatogram signals without causing the baseline level to rise or the intensity of the chromatogram peak to decrease. The chromatograph/mass spectrometer includes a chromatograph unit for separating a sample into components in the order of time, a mass spectrometer unit for analyzing the components of the sample, and a signal generator for producing a signal carrying a chromatogram obtained by the analysis. It also includes a chromatogram composer for receiving signals of plural chromatograms simultaneously measured under different conditions, for choosing the largest value of the plural signals for each point in time, and for integrating the chosen values to produce a composite chromatogram.

Chromatograph/mass spectrometer

In an ion trap mass spectrometer including a ring electrode and a pair of end cap electrodes placed opposite each other with the ring electrode therebetween, where an ion trap space is defined by the ring electrode and the pair of end cap electrodes, the frequency determining section of the controller determines a plurality of frequencies or a plurality of frequency channels each corresponding to a mass to charge ratio of an ion to be selected. The wide-band RF signal generator generates a wide-band RF signal having a plurality of notches each corresponding to each of the plurality of frequencies or the plurality of frequency channels. Then the voltage controller applies a voltage corresponding to the wide-band RF voltage to the pair of end cap electrodes, whereby ions having mass to charge ratios corresponding to the frequencies or frequency channels remain in the ion trap space but other ions are ejected from the ion trap space.

Ion trap mass spectrometer

The present invention proposes a liquid chromatograph/mass spectrometer (LC/MS) constructed so that only necessary data are efficiently collected, and that the apparent dynamic range and/or the operational condition of the MS part is appropriately changed according to the concentrations and/or the qualitative information of the sample components coming from the LC part. In the LC/MS, the passage of the carrier liquid is designed so that the carrier liquid containing the sample is first introduced to an auxiliary detector and then to a main detector (mass spectrometer) with a delay of a preset time period. During the analysis, a controller constructs a chromatogram from the output signal of the auxiliary detector and analyzes its waveform to determine in real-time a time period ts -te corresponding to each peak in the chromatogram. Then, the controller collects the measurement data by the main detector only within a time period ts -te which has a delay of the preset time period &Dgr;t from the above time period ts -te

Liquid chromatograph/mass spectrometer

A method of producing a broad-band signal including a plurality of component frequencies of regular or irregular intervals, where the broad-band signal is used to apply an alternating voltage to the end cap electrodes of an ion trap mass spectrometer. The method includes the following steps: (S ) a sinusoidal signal having one of the component frequencies with 0&deg; initial phase angle is generated; (S ) the sinusoidal signal is added to a current temporary superposed signal to produce an addition signal; (S ) the sinusoidal signal is subtracted from the current temporary superposed signal to produce a subtraction signal; (S -S ) either of the addition signal or the subtraction signal is selected that has a smaller amplitude as a next temporary superposed signal; and (S ) the steps are repeated for all the component frequencies.

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Kyoto, Japan

Yoshikatsu Umemura