Jeol Ltd.

Ayumi Kubo

Masaaki Ubukata

Kenji Nagatomo

A first searcher executes a primary search with respect to a primary library based on a sample mass spectrum. The primary library includes a plurality of standard mass spectra. When a judging unit judges that a search range is to be enlarged, a second searcher executes a secondary search with respect to a secondary library based on the sample mass spectrum. The secondary library includes a plurality of predicted mass spectra produced from a plurality of molecular structures.

Sample analyzing apparatus and method

A composition estimation target peak is selected from a mass spectrum of a sample, and a group of measured isotope peaks related to the composition estimation target peak is selected. A composition candidate for the sample is estimated based on the composition estimation target peak. A distribution of a theoretical isotope peak corresponding to the composition candidate is calculated. Presence or absence of an adduct ion or a desorbed ion in the sample is determined based on a first mass difference between isotopes in a distribution of the measured isotope peaks and a second mass difference between isotopes in the distribution of the theoretical isotope peak.

Mass spectrometry method and information processing device

An evaluation section identifies, in a list of candidate compounds, a group of candidate compounds having the degree of reverse similarity greater than or equal to a threshold s. When all candidates in the group of candidate compounds have differences between the degrees of similarity that are greater than or equal to a threshold s, the evaluation section judges that there is a composite state. The difference between the degrees of similarity is computed by subtracting the degree of forward similarity from the degree of reverse similarity. The similarity ratio may be used in place of the difference between the degrees of similarity.

Apparatus and method for processing mass spectrum

Each estimated composition candidate is evaluated based on a mass spectrum produced using soft ionization and a mass spectrum produced using hard ionization. In the evaluation, a comparison between two measured isotope patterns (primary pattern matching), and a comparison between the measured isotope pattern and a theoretical isotope pattern (secondary pattern matching) are applied stepwise.

Mass spectrum processing apparatus and method

An extraction section extracts a basic pattern of chemical noise included in a mass spectrum. A generation section generates pseudo chemical noise as a connected body of a plurality of pseudo fragments generated by intensity correction of the basic pattern. A removal section removes the pseudo chemical noise from the mass spectrum.

A composition of a focused portion corresponding to a portion of a molecular ion is estimated as a partial composition based on a mass of the focused portion. An initial composition search range is modified based on the partial composition. A composition of the molecular ion is estimated as an overall composition based on a mass of the molecular ion under a modified composition search range. A way of modifying the composition search range may include a method for modifying a lower limit to a range of the number of atoms and a method for adding a new range of the number of atoms associated with a new chemical element.

Composition estimating apparatus and method

A first mass spectrum including a fragment ion peak is generated under application of a first ionization method. A second mass spectrum including a molecular ion peak is generated under application of a second ionization method. These mass spectra are synthesized to generate a synthesized mass spectrum. On the synthesized mass spectrum, difference information, such as a mass difference and difference composition, is calculated between the molecular ion peak and the fragment ion peak.

There is provided a mass spectrometry data processor allowing for easy selection of a compositional formula for a sample component to be analyzed (analyte) even in general mass spectrometry applications. The mass spectrometry data processor is used to perform a qualitative analysis of the sample component based both on a first mass spectrum obtained by ionizing the sample component by a soft ionization method and on a second mass spectrum generated by cleavage of the sample component. The data processor includes: a molecular ion peak detector for detecting one molecular ion peak from the first mass spectrum; a fragment ion peak detector for detecting plural fragment ion peaks from the second mass spectrum; a composition estimator for obtaining estimated compositional formulas for the sample component from the molecular ion peak and obtaining estimated compositional formulas for fragments constituting the sample component from the fragment ion peaks; an assignment validity decision device for making decisions as to whether the estimated compositional formulas for the fragments can be assigned to the estimated compositional formulas for the sample component; and a degree of coincidence computing section for computing degrees of coincidence of the estimated compositional formulas for the fragments with the estimated compositional formulas for the analyte based on results of the decisions made by the assignment validity decision device.

Apparatus and method for processing of mass spectrometry data

A mass spectrometry data processing apparatus includes a data processing part and a calculation part. The calculation part calculates differences in mass among all pieces of the peak data from the peak list, calculates an intensity ratio that is a ratio of intensity between two pieces of the peak data used in calculating the difference, and generates difference-intensity ratio data. Further, the calculation part retrieves difference-intensity ratio data having the difference included in a section, calculates a sum of the intensity ratio of the retrieved difference-intensity ratio data, and calculates difference-intensity ratio distribution data.

Mass spectrometry data processing apparatus, mass spectrometry system, and method for processing mass spectrometry data

A mass spectrometry data analysis method for analyzing a specimen having a composition where two different reference chemical structures A and B that are each repeated, includes acquiring exact mass information of each peak in a mass spectrum of the specimen by mass spectrometry, acquiring Kendrick mass defect information Dand Dwhere a decimal number part has been extracted from mass information obtained by performing Kendrick mass conversion computation processing on exact mass information of each peak, acquiring mass defect information dand dwhere a decimal number part has been extracted from mass information of B based on A and A based on B of the reference chemical structures A and B, calculatingregarding D, D, d, and d, and obtaining degree-of-polymerization information nand n, and displaying plots corresponding to each peak on two-dimensional coordinates where nand nare axes.

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Tokyo, Japan

Ayumi Kubo