A method of mass spectrometry is disclosed comprising: a) separating first ions or components of an analyte sample according to a physicochemical property other than ion mobility; b) separating said first ions or second ions formed from said components according to ion mobility; c) detecting the intensities of said first ions, or detecting the intensities of second ions formed from said components, or detecting the intensities of ions derived from said first or second ions; wherein the intensity of the ions detected at any given time is recorded together with an associated value of said physicochemical property and an associated value of said ion mobility so as to obtain spectral data; d) examining the intensities of the spectral data as a function of said ion mobility so as to detect an intensity peak in said spectral data, determining a discrete value of ion mobility for said peak, and defining a window of values of ion mobility that encompasses said discrete value; and e) filtering said spectral data so as to include only spectral data that has been associated with values of ion mobility that are within said window of ion mobility values.

Methods and systems for separating and/or quantifying peptides using differential mobility spectrometry (DMS) are provided herein. In accordance with various aspects of the applicant's teachings, the methods and systems can provide for the separation of one or more peptides, for example, peptides that may be difficult to separate with conventional techniques, such as mass spectrometry (MS), by complexing the peptides with a metal cation (e.g., Ca2+) prior to DMS. In some aspects, the present teachings can prevent proton stripping from ionized peptides that can occur in DMS to prevent unintended and/or undesirable alterations to the peptide's charge state distribution.

Systems and methods are provided for providing a DMS precursor ion survey scan. An ion source configured to receive a sample is instructed to ionize the sample using a processor. A DMS device configured to receive ions from the ion source is instructed to separate precursor ions received from the ion source and transmit precursor ions using two or more CoVs using the processor. A mass analyzer configured to receive transmitted precursor ions from the DMS device is instructed to measure the m/z intensities of the transmitted precursor ions across an m/z range at each CoV of the two or more CoVs using the processor. The measured m/z intensities of the transmitted precursor ions received from the mass analyzer are stored as a function of m/z value and CoV using the processor. This produces a stored two-dimensional mapping of m/z intensities of the precursor ions of the sample.

A method of tandem mass spectrometry is disclosed. A quasi-continuous stream of ions from an ion source (20) and having a relatively broad range of mass to charge ratio ions is segmented temporally into a plurality of segments. Each segment is subjected to an independently selected degree of fragmentation, so that, for example, some segments of the broad mass range are fragmented while others are not. The resultant ion population, containing both precursor and fragment ions, is analyzed in a single acquisition cycle using a high resolution mass analyzer (150). The technique allows the analysis of the initial ion population to be optimized for analytical limitations.

An ion filter for a mass spectrometer, the apparatus comprising an ion modifier; an ion selector configured to select a subset of a sample of ions based on their mobility in a gas; and a controller configured to operate the ion modifier in a first mode to modify the ions selected by the ion selector to provide daughter ions, and configured to operate the ion modifier in a second mode to output the ions selected by the ion selector; wherein the ion filter is adapted for providing output ions from the ion modifier to an intake of a mass spectrometer.

The present invention is based on the finding that enrichment of D3-creatinine in a urine sample following oral administration of a single defined dose of D3-creatine can be used to calculate total-body creatine pool size and total body skeletal muscle mass in a subject. The invention further encompasses methods for detecting creatinine and D3-creatinine in a single sample. The methods of the invention find use, inter alia, in diagnosing disorders related to skeletal muscle mass, and in screening potential therapeutic agents to determine their effects on muscle mass.

Provided are methods for determining the amount of lacosamide in a sample using mass spectrometry. The methods generally involve ionizing lacosamide in a sample and detecting and quantifying the amount of the ion to determine the amount of lacosamide in the sample.

Provided are methods for determining the amount of tamoxifen and its metabolites in a sample by mass spectrometry. In some aspects, the methods provided herein determine the amount of norendoxifen. In some aspects, the methods provided herein determine the amount of norendoxifen and tamoxifen. In some aspects, the methods provided herein determine the amount of norendoxifen and other tamoxifen metabolites. In some aspects, the methods provided herein determine the amount of tamoxifen, norendoxifen, and other tamoxifen metabolites.

The invention “Ion Trap Array (ITA)” pertains generally to the field of ion storage and analysis technologies, and particularly to the ion storing apparatus and mass spectrometry instruments which separate ions by its character such as mass-to-charge ratio. The aim of this invention is providing an apparatus for ion storage and analysis comprising at least two or more rows of parallel placed electrode array wherein each electrode array includes at least two or more parallel bar-shaped electrodes, by applying different phase of alternating current voltages on different bar electrodes to create alternating electric fields inside the space between two parallel electrodes of different rows of electrode arrays, multiple linear ion trapping fields paralleled constructed in the space between the different rows of electrode arrays which are open to adjacent each other without a real barrier. This invention also provides a method for ion storage and analysis involving with the trapping, cooling and mass-selected analyzing of ions by this apparatus mentioned which constructs multiple conjoint linear ion trapping fields in the space between the different rows of electrode arrays.

An interface for receiving ions in a carrier gas from an atmospheric pressure ion source at a spectrometer that is configured to analyse the received ions at a lower pressure includes an interface vacuum chamber having a downstream aperture; a support assembly defining an axial bore arranged to allow a removable capillary tube to extend therethrough; ions being received from the atmospheric pressure ion source through the capillary tube and directed towards the downstream aperture; and a jet disruptor, positioned downstream from the axial bore and configured to disrupt gas flow between the axial bore and the downstream aperture only when the capillary tube is not fully inserted through the axial bore.