accurate mass

accurate mass

The mass of an ion of specified isotopic composition, which is calculated by summing the exact masses of the constituent atoms. The empirical formula of an ion can be deduced from the measured accurate mass of the ion if the ion mass is low enough to limit the number of formulaic possibilities and if the exact mass value is accurately known.
References in periodicals archive ?
Contract notice: Ultra high performance liquid chromatograph (uhplc) with diode detector (dad) coupled to a high resolution mass spectrometer and accurate mass with lap time analyzer (q-tof)
Although in everyday life it will appear that not much has changed, the redefinition of the kilo will ensure it remains stable, and enable more accurate mass measurements in the future.
Modern high-resolution accurate mass (HRAM) technologies are also leading to improved reproducibility in biomarker verification.
Essential oils were analyzed by high-resolution gas chromatography coupled with accurate mass time-of-flight mass spectrometry.
The Q Exactive HF-X instrument delivers fast and accurate mass analysis, plus two-to-three-fold sensitivity improvements, delivering the same number of protein identifications in half the time required of previous models.
Accurate mass detection allows a researcher to be 99 percent confident in the identification of molecule A versus molecule B--something that is extremely helpful in the search for molecular disease biomarkers.
Though both methods acquire data in a nontargeted fashion, suspect screening differs from the truly nontargeted analysis in that it searches for analytes against a user-defined chemical database or existing chemical inventories, paired with software-matching algorithms that make use of accurate mass and isotope patterns.
Shimadzu's high-resolution accurate mass quadrupole time-of-flight mass spectrometers used in conjunction with PREMIER Biosoft's SimLipid and SimGlycan software solutions will allow scientists to perform rapid identification and quantitation of lipids and glycans from complex biological mixtures in high throughput mode, the firms said.
Though it is true that human life span, on average, has increased greatly within the past few centuries, especially since accurate mass population records have been kept, but the same fallacy that befalls the Framingham Heart Study besmirches these statistics as well.
Accurate mass measurements define a unique elemental composition ([C.sub.c][H.sub.h][N.sub.n][O.sub.o][S.sub.s]) from singly charged ions, such as [[M+H].sup.+], [[M+Na].sup.+], [[M+K].sup.+], [[M-H].sup.-], and [[M+Cl].sup.-], where M corresponds the neutral molecule [5, 10-13].
The peptides are then analyzed by reverse phase chromatography coupled to High Resolution Accurate Mass (HRAM) mass spectrometry.
Thermo Scientific Orbitrap GC-MS systems have been updated with new capabilities in high resolution accurate mass (HRAM) GC-MS, designed to provide users across metabolomics, food safety, environmental, pharma and toxicology applications with data accuracy.