摘要:
The present invention provides a tandem type mass analysis system capable of carrying out the differential analysis with high efficiency by the tandem type mass analysis. A predetermined number of m/z regions are set up for carrying out the mass analysis with the all ions included therein being dissociated collectively for each m/z region so as to obtain measurement MS2 data. By comparing the measurement MS2 data with reference MS2 data stored in a reference data base, a difference thereof is detected. For the m/z region with a differential component detected, the mass analysis is carried out collectively without dissociation for the all ions included therein so as to obtain measurement MS1 data. By comparing the measurement MS1 data with the reference MS1 data, a difference thereof is detected. From the difference thereof, a parent ion considered to be the differential component factor is presumed for carrying out the mass analysis with the same being dissociated.
摘要:
For the achievement of data transfer time reduction, removal of noise data, and analytical efficiency improvement in an ADC data processing function of a time-of-flight mass spectrometer, the mass spectrometer comprises a data acquisition circuit including: an A/D converter; a signal intensity addition memory that stores data of ion signals such as a time range and the number of measurements and performs an addition process; a voltage value frequency addition memory that performs an addition process of frequencies of voltage values of the predetermined time range and the number of measurements and stores addition results; a threshold level computation circuit that computes a predetermined threshold level from the results in the memory; a compression memory that extracts only data exceeding the threshold level from the data in the signal intensity addition memory; and a counter that controls a measurement time for data acquisition and the operation of each circuit.
摘要:
According to the existing mass spectrometric system, whether or not the informations are sufficient for analyzing substances (particularly proteins, sugars, etc.) cannot be judged in the process of measurement. Further, it is difficult to find out isomers having just the same mass number or compounds very close in mass only from the MS data. According to this invention, whether or not the retention time in the LC (or GC) of peptide formed at the time of enzymatic decomposition of protein coincides with the predicted retention time assumed from the amino acid sequence predicted from MS2 mass spectrometry data is judged within the actual time period of measurement, and thereby the quality of MS2 mass spectrometry data (quantity of information) is judged.
摘要:
A mass spectrometer according to the present invention has an ionization source for generating ions; an ion trap for accumulating the ions; a time-of-flight mass spectrometer for performing mass spectrometry analysis on the ions by use of a flight time; a collision damping chamber disposed between the ion trap and the time-of-flight mass spectrometer and having a plurality of electrodes therein, which produce a multi-pole electric field, wherein a gas is introduced into the collision damping chamber to reduce kinetic energy of the ions ejected from the ion trap; and an ion transmission adjusting mechanism disposed between the ion trap and the collision damping chamber to allow or prevent injection of the ions from the ion trap to the collision damping chamber. The mass spectrometer provides greatly enhanced qualitative and quantitative analysis capabilities, as compared with conventional techniques.
摘要:
The invention intends to provide an atomic absorption spectrophotometer which can establish a uniform heat distribution during heating of a sample and can improve analysis accuracy and analyzing efficiency. For this purpose, a graphite tube type cuvette mounted in a graphite atomizer furnace for an atomic absorption spectrophotometer comprises a large-diameter portion for retaining a sample in place, a small-diameter portion connected to the large-diameter portion and having a smaller diameter than the large-diameter portion, and a step portion for demarcating between the large-diameter portion and the small-diameter portion. The graphite tube type cuvette is formed such that its cross-sectional area in a plane perpendicular to the direction of passage of an electric current supplied to the cuvette is the same in any of the large-diameter portion, the small-diameter portion and the step portion. The amount of resistance heat is thereby also the same in any portions.
摘要:
In a data acquisition system of ADC system, a log amplifier is provided at the pre-stage of an A/D converter, a signal amplified by the log amplifier having a nonlinear input-output characteristic is A/D-converted, and an adding operation of data is performed while reconverting a voltage value data which is converted to a nonlinear characteristic to data with a linear scale according to a table memory for reverse-log conversion. A known voltage value is inputted into the log amplifier to perform measurement, and calibration of the table memory is performed by storing the voltage value and the voltage value data after A/D-converted.
摘要:
The present invention can provide a mass spectrometric system judging whether a measurement target is a substance required by an operator within an actual measurement time, when a substance (particularly such as protein or sugar chains) is analyzed. In the mass spectrometric system using a tandem mass spectrometer, a particular substance obtained by separating a sample is ionized, and mass analysis of the ionized substance is performed to obtain a spectrum. This spectrum is compared with a particular spectrum stored in advance, to thereby determine whether both the spectra match with each other. When a match is determined, a particular ion is further ionized within a particular time for detailed analysis. The invention also provides a mass spectrometric method, a diagnosis system and an inspection system each using the mass spectrometric system, and a program for operating a computer to control those systems with desired functions.
摘要:
During the structural analysis of a protein or peptide by tandem mass spectroscopy, a peptide ion derived from a protein that has already been measured and that is expressed in great quantities is avoided as a tandem mass spectroscopy target. A peptide derived from a minute amount of protein, which has heretofore been difficult to analyze, can be automatically determined as a tandem mass spectroscopy target within the real time of measurement. Data concerning a protein that has already been measured and a peptide derived from the protein is automatically stored in an internal database. The stored data is collated with measured data with high accuracy to determine an isotope peak. In this way, the process of selecting a peptide peak that has not been measured as the target for the next tandem analysis can be performed within the real time of measurement and a redundant measurement of peptides derived from the same protein can be avoided. The information contained in the MSn spectrum is effectively utilized in each step of the MSn involving a multi-stage dissociation and mass spectroscopy (MSn), so that the flows for the determination of the next analysis content and the selection of the parent ion for the MSn+1 analysis, for example, can be optimized within the real time of measurement and with high efficiency and accuracy. Thus, a target of concern to the user can be subjected to tandem mass spectroscopy without wasteful measurement.
摘要:
In a data acquisition system of ADC system, a log amplifier is provided at the pre-stage of an A/D converter, a signal amplified by the log amplifier having a nonlinear input-output characteristic is A/D-converted, and an adding operation of data is performed while reconverting a voltage value data which is converted to a nonlinear characteristic to data with a linear scale according to a table memory for reverse-log conversion. A known voltage value is inputted into the log amplifier to perform measurement, and calibration of the table memory is performed by storing the voltage value and the voltage value data after A/D-converted.
摘要:
In order to provide an equipment that permits easy elimination of interference ions even in a low resolution mass spectrometer, the isotope mass number information and the isotope presence ratio information for each element are stored, and processing is done as is shown in FIG. 1 using such information and the measurement results, and the amount of target elemental ions is calculated by calculating and eliminating the amount of interference caused by other elemental isotopes to the target element. Because of this, when carrying out element analysis using a mass spectrometer with a relatively low resolution, the user can easily obtain the measurement result of the amount of any target elemental ions.