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.

Methods and system for identifying and quantifying antibody fragments and identifying the site of fragmentation on an antibody are provided herein.

The present invention relates to the field of protein characterization, and in particular to methods for characterizing high molecular weight species of a therapeutic protein by implementing a workflow including using a post-column denaturation-assisted SEC-MS method that allows highly specific, sensitive, and comprehensive characterization of high molecular weight species.

This document relates to methods for detecting and quantifying heavy and light chains of immunoglobulin using mass spectrometry techniques.

Methods of quantifying a N.sup.2-(1-carboxyethyl)-2′-deoxyguanosine (CEdG) levels in biological samples and comparing those levels to known normal levels can diagnose a number of metabolic disorders or complications associated therewith, including diabetes, its associated complications, and cancer. Methods can also determine whether therapies for disorders are effective by measuring CEdG levels before and after treatment. Measurement of CEdG levels is achieved by using liquid chromatography electrospray ionization tandem mass spectrometry.

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.

Disclosed are native liquid chromatography-mass spectrometry systems and methods of use. A native liquid chromatography-mass spectrometry system can include a liquid chromatography system capable of separating a sample; and an electrospray ionization mass spectrometry (ESI-MS) system in fluid communication with the liquid chromatography system, wherein the ESI-MS system comprises a multi-nozzle electrospray ionization emitter and a system for modifying a desolvation gas and a mass spectrometer, wherein the mass spectrometer is configured to receive ions and characterize mass to charge ratio of ions.

A kit or composition for in situ simultaneously derivatization of 14 phenol and carboxylic acid metabolites of benzene, toluene, ethyl benzene, and xylene (BTEX) in a urine sample is disclosed. The derivatization imparts a positive charge to phenol and carboxylic acid for subsequent LC-MS analysis. Limit of detection reached part-per-trillion levels for o-Cresol and part-per-billion levels for the remaining BTEX metabolites. BTEX metabolites can be detected in less than 35 mins according to one embodiment of the invention. Methods, kits and compositions disclosed herein can be used for in situ simultaneous derivatization of phenol and carboxylic acid in aqueous solution in general.

The invention generally relates to electrophoretic mass spectrometry probes and systems and methods of uses thereof. In certain aspects, the invention provides a mass spectrometry probe having a hollow body with a distal tip, an electrically conductive hollow conduit, and an electrode. The electrically conductive hollow conduit may be operably coupled to a reservoir and a power source, and the electrically conductive hollow conduit may be configured to transport a liquid sample into the hollow body and polarize the liquid sample as it flows through the electrically conductive hollow conduit and into in the hollow body. The electrode and the electrically conductive hollow conduit are disposed within the hollow body (e.g., at different heights within the hollow body).

Disclosed is an emitter device configured to operate as part of an electrospray ionization mass spectrometry device, the emitter device providing droplets of a liquid containing material to be analyzed. Also disclosed are methods of use of the emitter device 1.