Abstract: Apparatus is provided and an IDA method is modified to detect and separately dissociate alkali-metal adducts of a compound. An ion source device ionizes one or more compounds of a sample, producing an ion beam. A mass filter selects a mass range of precursor ions from the ion beam, a mass analyzer measures intensities and m/z values of the precursor ions, and one or more of the precursor ions are selected for a peak list. For each pair of precursor ions of the peak list, if an m/z difference between the pair corresponds to an m/z difference between an alkali metal ion and another alkali metal ion or a proton, an ExD device is used to dissociate one precursor ion or both precursor ions of the pair using the processor. A CID device is used to dissociate all other precursor ions of the peak list.

Abstract: Systems and methods are disclosed for determining if the dynamic range of quantitation in mass spectrometry can be extended. A DIA method is performed on a sample for a compound of interest at each acquisition time of a plurality of acquisition times. A plurality of product ion spectra are produced for each window of two or more precursor ion mass selection windows. A known product ion of the compound of interest is selected. Two or more XICs are calculated from two or more different precursor ion windows for the known product ion. A ratio of one XIC of the two or more XICs to at least one other XIC of the two or more XICs is calculated. If the ratio is above a threshold, the XIC is used in the quantitation. If not, two or more XICs can be combined into a single XIC that is used for the quantitation.

Abstract: Systems and methods are disclosed for determining if the dynamic range of quantitation in mass spectrometry can be extended. A DIA method is performed on a sample for a compound of interest at each acquisition time of a plurality of acquisition times. A plurality of product ion spectra are produced for each window of two or more precursor ion mass selection windows. A known product ion of the compound of interest is selected. Two or more XICs are calculated from two or more different precursor ion windows for the known product ion. A ratio of one XIC of the two or more XICs to at least one other XIC of the two or more XICs is calculated. If the ratio is above a threshold, the XIC is used in the quantitation. If not, two or more XICs can be combined into a single XIC that is used for the quantitation.

Abstract: A novel atmospheric pressure ionization device for the transport of charged particle produced by at atmospheric pressure to a mass analyzer includes a liquid shield between the particle source and the sample inlet into the mass analyzer. The liquid shield may be in the form of a disk with a central aperture and acts as a spray splitter and aerofocusing device which increases the flow rate of a liquid sample into the analyzer. The mass analyzer is located in a high vacuum region and an intermediate low vacuum region is provided between the sample inlet and the analyzer. An ion optical system includes electrostatic lens assemblies in said vacuum regions for transporting charged particles from the inlet to the analyzer.