Abstract: Methods and systems for controlling a filament of an electron emitter associated with an ion reaction cell in accordance with various aspects of the present teachings may account for inter-filament and inter-instrument variability and can provide improved reproducibility in EAD experiments and ease of use. In some aspects, a method of operating an ion reaction device of a mass spectrometer system is provided. The method comprises applying a calibration drive voltage to a filament of an electron emitter associated with an ion reaction cell and determining a value representative of the calibration electron emission current generated by the filament while having the calibration drive voltage applied thereto. A calibration saturation voltage can be determined by iteratively increasing the calibration drive voltage applied to the filament and determining the value of the calibration electron emission current at each corresponding calibration drive voltage until the filament reaches a saturation condition.

Abstract: An apparatus includes a first electrode and a second electrode. The second electrode is placed in parallel with the first electrode to provide constant gap distance. The gap between the first electrode and the second electrode is at atmospheric pressure. Ions are introduced into the center of the gap and travel through the apparatus in a direction parallel to the first electrode and the second electrode. The apparatus is configured as a high-field symmetric-waveform apparatus for filtering high mobility ions or for fragmenting ions. The apparatus is also configured for three modes of operation: as a conventional DMS; as a filter high mobility ions; and as fragmentation device. A symmetric electric field is produced in the gap with a maximum density normalized field strength greater than 10 Td to filter high mobility ions and with a maximum density normalized field strength greater than 100 Td to fragment ions.

Abstract: In various aspects, methods and systems disclosed herein are capable of operating a Fourier Transform Mass Spectrometry (FTMS) quadrupole mass analyzer in two operational modes: transmitting mode and trapping mode. In the trapping mode, ions are first trapped and cooled within the FTMS quadrupole mass analyzer prior to being subjected to an excitation pulse and ejected from the FTMS quadrupole mass analyzer for detection. However, in transmitting mode, the FTMS quadrupole mass analyzer may provide more rapid analysis because the excitation pulse is applied to the ions of an ion beam that is being continuously transmitted through the FTMS quadrupole mass analyzer.

Abstract: A method and system for detecting a signal measurement error, the method including providing a well plate including error correction wells and sample wells, each sample well including a single sample, and each error correction well including a mixture of samples from two or more sample wells. The method includes receiving an aliquot from the wells at a sample receiver, measuring a signal for the received aliquot, calculating an expected signal for each of the error correction wells, comparing the measured signal to the calculated expected signal for each error correction well, and determining whether an error exists in the signal of at least one sample well. When the error exists, the method correlates the error to one or more sample wells.

Abstract: A method of performing mass spectrometry is disclosed. which comprises introducing a plurality of ions into an ion guide of a mass spectrometer via an inlet orifice thereof. where the ion guide includes a plurality of rods arranged in a multipole configuration and spaced from one another to provide a passageway for transit of the ions therethrough. applying RF voltages to the rods so as to generate an electromagnetic field within the passageway for providing radial confinement of the ions passing through the passageway, identifying a space charge effect, which can adversely affect operation of the mass spectrometer, based on detection of a variation of an intensity of an ion detection signal associated with at least one ion population transmitted through said ion guide and having an m/z ratio greater than a threshold, and in response to said identification of the adverse space charge effect. adjusting at least one of frequency and amplitude of the RF voltages to counteract said space charge effect.

Abstract: Leak detection systems and methods in accordance with various aspects of the present teachings can, in various embodiments, sequester fluid leaking from the interface between a sample source and the inlet of the ion source, alert an operator as to a leak condition, and/or automatically terminate the experiment. In various aspects, a liquid leak detection system is accordance with the present teachings comprises a collection basin configured to couple to a proximal end of a conduit in fluid communication with a discharge end of an ion source of a mass spectrometer such that the proximal end of the conduit extends through the internal volume of the basin.

Abstract: In one aspect, a mass spectrometer is disclosed, which comprises a Fourier Transform (FT) mass analyzer having an input port for receiving ions and an exit port through which the ions exit the FT mass analyzer, a detector disposed downstream of said FT analyzer for detecting ions exiting the FT analyzer, and a multi-segment ion guide having a plurality of segments, said multi-segment ion guide being disposed upstream of said FT mass analyzer and having an input port for receiving ions and an output port through which ions exit the FT mass analyzer. The segments of the ion guide are configured to be independently activated via application of a DC offset voltage thereto so as to adjust a length through which ions passing through the ion guide experience collisional cooling.

Abstract: An electrospray probe for use in an electrospray ion source is disclosed, which comprises a cannula extending from a proximal end having an inlet aperture for receiving a liquid sample containing at least one analyte to a discharge emitter end having an outlet aperture through which charged liquid droplets containing ions of said analyte are discharged, and an electrically conductive coating covering at least a portion of an external surface and at least a portion of an internal surface of said emitter end.

Abstract: MS-based methods and systems are provided herein in which a desorption solvent desorbs one or more analyte species from an SPME device within a sampling interface that is fluidly coupled to an ion source for subsequent mass spectrometric analysis. In accordance with various aspects of the applicants teachings, the sampling interface includes an internal sampling conduit that provides increased interaction between the desorption solvent and the sampling substrate, thereby improving mass transfer (e.g., increased extraction or desorption speed).

Abstract: Methods and systems for mass spectrometry are disclosed. In one example, a method comprises: receiving, by a mass spectrometer via a sampling system operably connected thereto, at least one sample containing at least one known compound; modulat-ing at least one instrument parameter of the mass spectrometer through a plurality of instrument parameter values; analyzing the at least one sample while applying each of the plurality of instrument parameter values; acquiring a plurality of mass spectral (MS) datasets each corresponding to one of the applied plurality of instrument parameter values; encoding each of the plurality of MS datasets to generate a corresponding plurality of MS results each corresponding to one of the applied instrument parameter values; and compiling and storing the MS datasets and MS results in a spectral library in association with the applied instrument parameter values.

Abstract: A DMS device receives a curtain gas that includes a chemical modifier into its curtain plate. Before or while receiving ions of an analyte, the DMS device steps the CoV through a series of values in order to apply different CoV values to at least one precursor ion derived from the chemical modifier. For each CoV value of the series of values, a mass spectrometer selects and mass analyzes the at least one precursor ion. An intensity is produced for each CoV value of the series of values. An intensity versus CoV value peak is calculated from the intensities measured. A representative CoV value is calculated for the peak. The difference between the representative CoV value and known CoV values that represent an uncontaminated curtain plate is calculated. If the difference is greater than or equal to a predetermined threshold value, the curtain plate is determined to be contaminated.

Abstract: Method and devices for performing top down analysis of an antibody are described which involve utilizing an ion source to generate a plurality of ions from a sample containing at least one intact antibody. Further, transmitting said plurality of ions through a quadrupole rod set while applying an RF signal thereto and in the absence of a resolving DC voltage so as to preferentially transmit precursor ions having an m/z value greater than a low mass cutoff of about 1500 m/z from the quadrupole rod set to an ECD cell. The method and device can also performing an ECD reaction in the ECD cell on said precursor ions and also detect reaction products from the ECD reaction.

Abstract: Before a sample is introduced into a liquid sample delivery device, an ion source device receives aqueous mobile phase solution from the liquid sample delivery device and ionizes compounds of the aqueous mobile phase solution, producing an ion beam. A tandem mass spectrometer performs a first neutral loss scan of the ion beam with a first neutral loss value set to a molecular weight of a first known solvent, producing a first intensity, and performs a second neutral loss scan of the ion beam with a second neutral loss value set to a molecular weight of a second known solvent, producing a second intensity. A ratio of the first intensity to the second intensity is calculated. It is determined if the aqueous mobile phase solution is properly being delivered by the liquid sample delivery device based on the ratio.

Abstract: A high-voltage power supply system for a mass spectrometer comprises a ground-referenced power supply with a first transformer having a primary winding and a secondary winding, the primary winding is electrically coupled to a first source of AC power, and a floated bias voltage power supply with a second transformer having a primary winding and a secondary winding, the primary winding of the second transformer is electrically coupled to a second source of AC power. A return electrical path of the floated bias voltage power supply is electrically coupled to the ground-referenced power supply to bias an output voltage of the ground-referenced power supply. A floating shield is around the floating bias voltage power supply, and at least one resistive element is in the return electrical path of the floated bias voltage power supply to reduce noise coupled from the floated bias voltage power supply to the ground-referenced power supply.

Abstract: Methods and systems for adjusting instrument setting, improving fidelity of isotope pattern for mass spectra, and/or determining molecular mass with improved accuracy are disclosed. In one example, a method for determining Mmono of a compound of interest in a sample using a mass spectrometer is provided. The method comprises: (1) tuning or adjusting instrument setting of the mass spectrometer using at least one known compound, wherein the instrument setting comprises at least one parameter for improving accuracy; (2) analyzing the compound of interest using the adjusted instrument setting to obtain a mass spectrum thereof, wherein the mass spectrum comprises an isotope pattern thereof; and determining the Mmono of the compound of interest from the mass spectrum thereof.

Abstract: A method for determining a convolved peak intensity in a sample trace includes ejecting a plurality of sample ejections from a sample well plate. An ejection time log is generated which includes an ejection time of each of the plurality of sample ejections from the sample well plate. The plurality of sample ejections is analyzed with a mass analyzer. The sample trace of intensity versus time values is produced for the plurality of sample ejections based on the analysis. A known peak shape is obtained. A convolved peak intensity is determined for a convolved peak of the sample trace based at least in part on the known peak shape and the ejection time log.

Abstract: Methods and system that determines disulfide and trisulfide linkages within analytes (e.g., polypeptides) is described. In certain aspects. a sample comprising polypeptides (such as an antibody) may be subjected to dissociation using an electron activated dissociation (which can include electron capture dissociation and electron transfer dissociation) and the fragmentated portions are analyzed using a mass spectrometer to produce a spectrum. The spectrum is analyzed by a processor to identify peaks from the spectrum that are related to one another in the spectra by a separation of 32 mass units. In identifying an antibody comprising peptide segments linked via a trisulfide bond. for example, four different peaks representing two different peptides are searched for and identified representing a first peptide portion having mass/charge of A and A+32 and a second peptide having mass/charge of B and B+32.

Abstract: A method of ejecting a sample from a nebulizer nozzle fluidically coupled to a port via a transfer conduit includes receiving at the port a transport liquid and the sample. The transport liquid and the sample in the transfer conduit is transported from the port to a transfer conduit exit comprising an electrode tip. The transport liquid is ejected from the transfer conduit exit. The sample is ejected from the transfer conduit exit substantially simultaneously with ejecting the transport liquid. During ejection of the transport liquid and the sample from the transfer conduit exit, a pressure is generated at the transfer conduit exit substantially similar to a vapor pressure of the transport liquid.

Abstract: A system and method are provided for loading a sample into an analytical instrument using acoustic droplet ejection (“ADE”) in combination with a continuous flow sampling probe. An acoustic droplet ejector is used to eject small droplets of a fluid sample containing an analyte into the sampling tip of a continuous flow sampling probe, where the acoustically ejected droplet combines with a continuous, circulating flow stream of solvent within the flow probe. Fluid circulation within the probe transports the sample through a sample transport capillary to an outlet that directs the analyte away from the probe to an analytical instrument, e.g., a device that detects the presence, concentration quantity, and/or identity of the analyte. When the analytical instrument is a mass spectrometer or other type of device requiring the analyte to be in ionized form, the exiting droplets pass through an ionization region, e.g.

Abstract: Methods and systems for identifying analytes in a sample using mass spectrometry are provided. A method for identifying analytes in mass spectrometry data comprises: introducing a sample to a mass spectrometer; analyzing the sample with the mass spectrometer in a plurality of cycles; generating, for each cycle, a mass spectrum comprising at least one peak; annotating peaks in the mass spectrum based on their relationships; assigning best ion types to each peak; processing each cycle of the mass spectrum to assign a score to each of the at least one peak thereof with respect to the likely neutral mass related to the peak; grouping peaks that share a common neutral mass; and outputting the analyte neutral mass.