摘要:
The disclosure relates to a mass spectrometer for mass spectrometric examination of gas mixtures, including: an ionization device and an ion trap for storage and mass spectrometric examination of the gas mixture. In one aspect of the disclosure, the ionization device is embodied for supplying ions and/or metastable particles of an ionization gas and/or for supplying electrons to the ion trap for ionizing the gas mixture to be examined and the mass spectrometer is embodied to determine the number of ions and/or metastable particles of the ionization gas present in the ion trap and/or the number of ions of a residual gas present in the ion trap prior to examining the gas mixture. The disclosure also relates to the use of such a mass spectrometer and a method for mass spectrometric examination of a gas mixture.
摘要:
Every time a target sample is injected from an injector (12) of an LC unit (1) and a mass spectrometry for a target component in the sample is performed, a CD voltage applied to a conversion dynode of an ion detector (29) is switched. For each of the multiple CD-voltage levels, a data collector (32) collects noise data during a period of time where no component is present and intensity data of an ion originating from the target component, while the SN ratio calculator (33) calculates an SN ratio. After the actual measurement is completed, an optimum CD voltage determiner (34) compares the SN ratios calculated for each CD voltage, finds the CD voltage which gives the highest SN ratio, and stores this voltage in an optimum CD voltage memory (42) as an optimum CD voltage for the analysis conditions at that point in time and for the m/z of the analysis target. According to this method, even when the flow rate of the mobile phase is particularly high or when a hard-to-vaporize mobile phase is used, the CD voltage is appropriately set and a detection signal is obtained with high SN ratios.
摘要:
Systems and methods are provided for maximizing the data acquired from a sample in a mass spectrometry imaging experiment. An ion source device is instructed to produce and transmit to a tandem mass spectrometer a plurality of ions for each location of two or more locations of a sample. A mass range is divided into two or more mass window widths. For each location of the two or more locations, the tandem mass spectrometer is instructed to fragment the plurality of ions received for each location using each mass window width of the two or more mass window widths and to analyze resulting product ions. A product ion spectrum is produced for each mass window width, and a plurality of product ion spectra are produced for each location of the two or more locations.
摘要:
A method of mass spectrometry is disclosed comprising automatically and repeatedly performing multiple cycles of operation, wherein a cycle of operation comprises the steps of: (i) mass analyzing first ions; (ii) exposing the first ions to a first photo-dissociation device to form a plurality of second ions and mass analyzing the second ions; and (iii) exposing the first ions to a first photo-dissociation device to form a plurality of second ions, fragmenting the second ions to form a plurality of third ions and mass analyzing the third ions.
摘要:
An apparatus for determining the total amount of two or more substances in a liquid, at least one of said substances comprising a fluorescent substance, said apparatus comprising: a mass spectrometer device; a fluorometer device; and a processing means; wherein said mass spectrometer device is adapted to obtain a periodic measurement of the total amount of said two or more substances in the liquid, said fluorometer device being adapted to detect the fluorescent response of said at least one fluorescent substance in said liquid to an excitation signal, said processing means being programmed to determine a calibration factor by comparing a measurement obtained by the fluorometer device with said periodic measurement of the total amount of said two or more substances present obtained by the mass spectrometer device, the processing means subsequently using said calibration factor to determine measurements representative of the total amount of both fluorescent and non-fluorescent substances present in the liquid based upon the fluorescent response detected by the fluorometer device.
摘要:
The invention relates to the quantitative measurement of steroidal compounds by mass spectrometry. In a particular aspect, the invention relates to methods for quantitative measurement of steroidal compounds from multiple samples by mass spectrometry.
摘要:
The present invention relates to the identification of chemokine biomarkers predictive of future acute coronary syndromes including unstable angina pectoris (UAP). The present invention also identifies particular chemokines as potential therapeutic targets for intervention in cardiovascular diseases.
摘要:
An ion mobility spectrometry method comprising determining whether a sample comprises ions having a first characteristic, and in the event that it is determined that the sample comprises ions having the first characteristic, applying thermal energy together with a radio frequency, RF, electric field to parent ions so as to obtain daughter ions having a second characteristic for inferring at least one identity for the parent ions based on the first characteristic and the second characteristic.
摘要:
The invention provides compositions and methods for mass spectrometric (MS), organic synthesis, and applications of organo-trifluoroborate, for example, as mass tags for use in negative ion mode. When subject to MS fragmentation, organo-trifluoroborates preferentially undergo neutral losses of hydrogen fluoride (HF) or boron trifluoride (BF3) molecules, transferring the negative charge to the rest of the molecule. Such a fragmentation pattern is used to detect and quantitate analytes of interest after derivatization with organo-trifluoroborates.
摘要:
A composition, method, and kit for calibrating a mass spectrometer including a predetermined concentration of a calibrant having a mixture of amino acid polyethylene glycol compounds and a solvent for dissolving the calibrant. The calibrant can be used in either positive or negative ionization mode, and it can be used in calibrating an atmospheric pressure chemical ionization or an electrospray mass spectrometer. The calibrant can include a mixture to enable calibration across a broad range of masses.