The present disclosure pertains to method and system of characterizing a protein using an electrospray ionization source.

Methods are described for diagnosing or prognosing insulin resistance in diabetic and pre-diabetic patients, the method comprising determining the amount of insulin and C-peptide in a sample. Provided herein are mass spectrometric methods for detecting and quantifying insulin and C-peptide in a biological sample utilizing enrichment and/or purification methods coupled with tandem mass spectrometric or high resolution/high accuracy mass spectrometric techniques.

A dwell time calculation table (51a) showing a correspondence relation between a CID gas pressure inside a collision cell (31) and a dwell time for data collection is stored in a processing condition parameter memory (51) of a controller (50). In the table (51a), as the CID gas pressure becomes higher, the dwell time becomes longer. When an instruction to execute an MRM measurement mode is given, the controller (50) determines the dwell time in accordance with the currently set CID gas pressure, and controls a data collector (41) to accumulate detection signals from an ion detector (34) during the determined dwell time and obtain the accumulated value. If the CID gas pressure inside the collision cell (31) is high, a decrease in ion speed becomes remarkable, and the rising of the ion intensity becomes slow. However, if the dwell time becomes long, influences of the slow rising on the accumulated value are relatively reduced, and the accuracy of the accumulated value is enhanced. Accordingly, the quantitative accuracy can be enhanced.

In order to appropriately set MS.sup.m analysis conditions, an MS.sup.m-1 analysis executer (51) makes a mass spectrometer (20) perform an MS.sup.m-1 analysis (where m is an integer from 2 to n) to acquire three-dimensional data showing an intensity for each of the N m/z values and each of the M retention times (where N and M are natural numbers). Based on the three-dimensional data, a data matrix creator (41) creates data matrix X in which intensity data are arranged in N rows which differ from each other in m/z value and M columns which differ from each other in retention-time value. A matrix factorization executer (42) determines an N×K spectrum matrix S and K×M profile matrix P (where K is a natural number) by matrix factorization based on data matrix X so that this matrix X is approximated by product SP of the matrices S and P. An m/z detector (43) detects m/z of a precursor ion originating from a sample component from the values of the matrix elements in each column of matrix S. A retention time detector (44) detects the retention time of a sample component from the values of the matrix elements in each row of matrix P. Based on the m/z and retention time, an MS.sup.m analysis execution condition determiner (45) determines an execution condition of an MS.sup.m analysis including the selection and fragmentation of a precursor ion of a sample component. An MS.sup.m analysis executer (52) makes the mass spectrometer execute an MS.sup.m analysis based on the execution condition.

The invention discloses a detection method based on supercritical fluid chromatography (SFC) and post-column dicationic ionic liquid (DIL) charge complexation, which includes the following steps: (1) The supramolecular solvent (SUPRAS) was prepared by mixing heptanol, tetrahydrofuran, and water; (2) Sample pretreatment: the SUPRAS was used to extract the sample for subsequent analysis; (3) Analysis of perfluorinated compounds (PFCs) using SFC separation, post-column DIL-based charge complexation, and electrospray ionization-mass spectrometry (ESI-MS). The invention established a novel analytical method for the detection of PFCs in textiles incorporating post-chromatographic DIL-based charge complexation and SFC coupled with ESI-MS. The DIL reagent formed positively charged complexes with anionic analytes during the ESI process, facilitating MS detection in the positive ion mode with enhanced detection sensitivity.

A particle for emulating pollutant tracking in water has a florescent core. A semitransparent shell is formed around the florescent core.

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.

A method and system for injecting an unconcentrated sample into a receiving LC/MS/MS system that is configured to determine a concentration of one or more PFAS analytes within the unconcentrated sample, wherein the LC/MS/MS includes ESI. The unconcentrated sample is subjected to the following ESI conditions: i) a probe gas temperature of approximately 120° C. to approximately 180° C.; ii) a sheath gas heater setting of approximately 250° C. to approximately 400° C.; and iii) a sheath gas flow of approximately 8 L/min to approximately 12 L/min. The unconcentrated sample's concentration and/or an injected amount of the one or more PFAS analytes is determined.

A packaging for a needle-like component of a mass spectrometry (MS) system is provided. The packaging includes a receptacle configured for storing the needle-like component in a secured position inside the receptacle. The packaging further comprises an actuator configured to move the needle-like component from the secured position inside the receptacle to a mounting position in which the needle-like component projects out of the receptacle for mounting the needle-like component to the MS system.

Methods are described for measuring the amount of C peptide in a sample. More specifically, mass spectrometric methods are described for detecting and quantifying C peptide in a sample utilizing on-line extraction methods coupled with tandem mass spectrometric or high resolution/high accuracy mass spectrometric techniques.