Abstract:
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.
Abstract:
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.
Abstract:
An exact centroid spectrum with a mass number corrected is determined from a profile spectrum adjacent to a plurality of peaks. Regarding a profile spectrum determined by a mass spectrometer, overlapping with adjacent peaks occurs, and compounds having a plurality of peaks with different overlapping degrees is measured, a correction function is created from a relationship between an overlapping degrees with respect to the plurality of peaks and a shift of the mass number, and a centroid peak is corrected by the correction function when the profile spectrum is converted into the centroid spectrum.
Abstract:
A method for fractionating a sample solution includes the steps of setting a first mass spectrometry condition and mass range information; setting a second mass spectrometry condition and mass range information; executing a mass scan by the mass spectrum acquisition portion under the first mass spectrometry condition and obtaining first mass spectrum data; extracting first chromatogram data from the first mass spectrum data based on the first mass range information; executing a mass scan by the mass spectrum acquisition portion under the second mass spectrometry condition to obtain second mass spectrum data; extracting second chromatogram data from the second mass spectrum data based on the second mass range information; switching the first and second spectrometry conditions and repeating the mass scan cyclically; adding the first and second chromatograph data to obtain a chromatogram data; and operating the fraction collector based on the chromatogram data.
Abstract:
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 T2 corresponding to a measurement mass range are extracted as profile data. The data obtained within either a time range T1 before the arrival of an ion having the smallest m/z value or a time range T3 after 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.
Abstract:
An exact centroid spectrum with a mass number corrected is determined from a profile spectrum adjacent to a plurality of peaks. Regarding a profile spectrum determined by a mass spectrometer, overlapping with adjacent peaks occurs, and compounds having a plurality of peaks with different overlapping degrees is measured, a correction function is created from a relationship between an overlapping degrees with respect to the plurality of peaks and a shift of the mass number, and a centroid peak is corrected by the correction function when the profile spectrum is converted into the centroid spectrum.
Abstract:
A method for fractionating a sample solution includes the steps of setting a first mass spectrometry condition and mass range information; setting a second mass spectrometry condition and mass range information; executing a mass scan by the mass spectrum acquisition portion under the first mass spectrometry condition and obtaining first mass spectrum data; extracting first chromatogram data from the first mass spectrum data based on the first mass range information; executing a mass scan by the mass spectrum acquisition portion under the second mass spectrometry condition to obtain second mass spectrum data; extracting second chromatogram data from the second mass spectrum data based on the second mass range information; switching the first and second spectrometry conditions and repeating the mass scan cyclically; adding the first and second chromatograph data to obtain a chromatogram data; and operating the fraction collector based on the chromatogram data.
Abstract:
Disclosed is a Fourier transform infrared spectrophotometer, which comprises: a main interferometer section including a beam splitter, a fixed mirror, a movable mirror, and a phase plate disposed between the beam splitter and the fixed mirror; a control interferometer section having a quadrature control system for calculating a position of the movable mirror; a center-burst-position detection section operable, based on an input of interference signals and interferograms, to subject respective intensities of the interferograms to an addition processing while correcting a positional deviation of the movable mirror, so as to obtain a cumulative interferogram, and detecting a center burst position having a maximum intensity value in the cumulative interferogram; a center-burst-position storage section operable to store the detected center burst position; and a measurement-start-position determination section operable, based on the stored center burst position, to determine a measurement start position of the movable mirror during the measurement operation.
Abstract:
Disclosed is a Fourier transform infrared spectrophotometer, which comprises: a main interferometer section including a beam splitter, a fixed mirror, a movable mirror, and a phase plate disposed between the beam splitter and the fixed mirror; a control interferometer section having a quadrature control system for calculating a position of the movable mirror; a center-burst-position detection section operable, based on an input of interference signals and interferograms, to subject respective intensities of the interferograms to an addition processing while correcting a positional deviation of the movable mirror, so as to obtain a cumulative interferogram, and detecting a center burst position having a maximum intensity value in the cumulative interferogram; a center-burst-position storage section operable to store the detected center burst position; and a measurement-start-position determination section operable, based on the stored center burst position, to determine a measurement start position of the movable mirror during the measurement operation.
Abstract:
A mass spectrometer for a liquid chromatograph includes an atomization chamber into which a liquid sample from the liquid chromatograph is sprayed to be converted into ions, an intermediate chamber at a reduced inner pressure and a detection chamber containing a mass analyzer. A solvent-removing tube is between the atomization chamber and the intermediate chamber for causing liquid droplets containing these ions to pass through. A deflector with at least one pair of planar electrodes is disposed inside the intermediate chamber and opposite each other sandwiching in between the travel path of the ions. Voltage sources apply a variable DC voltage to the solvent-removing tube and different variable DC voltages to each of the electrodes. Data on voltages to be applied to the solvent-removing tube and to the electrodes for optimizing efficiency with which ions with different mass numbers are received by the mass analyzer are preliminarily obtained by using standard samples and stored in a memory device. A control unit serves to apply a specified voltage to the mass analyzer and simultaneously controls the voltage sources so as to have selected voltages applied to the solvent-removing tube and to the electrodes, according to the data stored in the memory.