Jeol Ltd.

Masaaki Ubukata

Ayumi Kubo

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

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.

In a mass spectrometry apparatus, an electric field is applied to an injected specimen to ionize the specimen, and mass spectrometry of the specimen is performed. In an emitter which ionizes the specimen, a flashing process to increase a temperature of the emitter is repeatedly performed at a short-time interval during an injection period of the specimen. A flashing current controller controls a flashing current value to be applied to the emitter to increase, in a long term, a flashing temperature which the emitter reaches in the flashing process.

Mass spectrometry apparatus, gas chromatograph-mass spectrometry apparatus, and flashing current control apparatus

Mass spectrometry for a specimen is repeatedly performed while stepwise changing a parameter (for example, a current value) of an emitter current. Based on a plurality of chromatograms generated by this process, an evaluation value table including a plurality of evaluation values is generated. An individual evaluation value shows a degree of tailing for individual peak included in each chromatogram. A parameter function is generated based on the evaluation value table. The parameter of the emitter current is controlled according to the parameter function.

Mass spectrometry system and emitter current control method

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.

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Tokyo, Japan

Masaaki Ubukata