An electrospray ionization system used in mass spectrometry provides for improved current measurement. The system includes a fluid union, a fluid column coupled with a first port of the fluid union, a power source coupled with the fluid union and configured to apply a voltage potential to the fluid union, and an electrospray emitter coupled with a second port of the fluid union. The power source is coupled with the first port and configured to apply the voltage potential to the first port to restrict current leakage from the fluid union. The current sensing circuit is configured to determine an electrical current flow between the power source and the at least one of the fluid union and the first port.

The present invention relates to the field of protein characterization, and in particular to methods for identifying critical quality attributes of therapeutic proteins by implementing a workflow including using a competitive binding assay with insufficient capture molecule followed by LC-MS.

A mass spectrometer includes: a probe having an electric conductivity; a probe moving unit configured to move the probe; a high voltage application unit configured to apply a high voltage to the probe located at an ion generation position where the tip of the probe is apart from the sample, so as to generate an ion from the sample adhered to the probe, the ion originating from a component in the sample; and a sample holding unit that includes a sample holder having a plurality of concave portions, each configured to hold the sample, and a base configured to hold the sample holder in a removable manner, the base including a mechanical element configured to move the sample holder in order to sequentially move each of the plurality of concave portions of the sample holder to the sample collection position.

The present invention comprises novel methods of continuously monitoring the performance of an atmospheric pressure ionization (API) system. The methods of the invention allow for improved quality monitoring of the processes that leads to the formation of ions at atmospheric pressure. The methods of the invention further allow for continuously monitoring for the quality of the ion formation process in API without the addition of extraneous material (such as labelled compounds or control known compounds) to the system being monitored.

The invention generally relates to systems and methods for separating ions at about or above atmospheric pressure. In certain embodiments, the invention provides systems that include an ionization source that generates ions and an ion trap. The ion trap is maintained at about or above atmospheric pressure and includes a plurality of electrodes and at least one inlet configured to receive a gas flow and at least one outlet. The system is configured such that a combination of a gas flow and one or more electric fields produced by the electrodes separates the ions based on mass-to-charge ratio and sends the separated ions through the at least one outlet of the ion trap.

Provided is a sample pretreatment device configured to apply, to the surface of a sample, a solution in which a predetermined substance is dissolved or dispersed. In order to properly and efficiently unclog a nozzle due to the deposition of the crystal of a matrix substance, the device includes a spray unit (3) including a solution tube (32) for the solution to pass through, a gas tube (33) for a spray gas to pass through, and a nozzle part (30) configured to spray the solution arriving at the terminal end of the solution tube by ejection of the spray gas through the gas tube, as well as a cleaning liquid supplier (4, 41) configured to put a cleaning liquid on an opening of the nozzle part from outside the spray unit.

An ion pulse generator (100) includes a triboelectric generator (110), an ion emitter (132) and a conductive surface (134). The triboelectric generator (110) includes a first electrode (114), a spaced apart second electrode (120) and a first triboelectric layer (116). The triboelectric generator (110) generates a predetermined amount of charge as a result of relative movement of the first triboelectric layer (116). The ion emitter (132) is electrically coupled to the first electrode (114). The conductive surface (134) is electrically coupled to the second electrode (120) and is spaced apart from the ion emitter (132) at a predetermined distance. Generation of the predetermined amount of charge causes formation of ions between the ion emitter (132) and the conductive surface (134).

Methods and systems for delivering a liquid sample to an ion source for the generation of ions and subsequent analysis by mass spectrometry are provided herein. In accordance with various aspects of the present teachings, MS-based systems and methods are provided in which the flow of desorption solvent within a sampling probe fluidly coupled to an ion source can be selectively controlled such that one or more analyte species can be desorbed from a sample substrate inserted within the sampling probe within a decreased volume of desorption solvent for subsequently delivery to the ion source. In various aspects, sensitivity can be increased due to higher desorption efficiency (e.g., due to increased desorption time) and/or decreased dilution of the desorbed analytes. The methods and systems described herein can additionally or alternatively provide for the selective control of the flow rate of the desorption solvent within the sampling interface so as to enable additional processing steps to occur within the sampling probe (e.g., multiple samplings, reactions).

Methods, systems and devices that allow independently applied pressures to a BGE reservoir and a sample reservoir for pressure-driven injection that can inject a discrete sample plug into a separation channel that does not require voltage applied to the sample reservoir and can allow for in-channel focusing methods to be used. The methods, systems and devices are particularly suitable for use with a mass spectrometer.

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., an electrospray ion source, prior to entering the mass spectrometer or other analytical instrument. The method employs active flow control and enables real-time kinetic measurements.