mass tolerance of * 1 u of the precursor ion molecular weight. A cross-correlation function is then used to provide a measurement of similarity between the mass-to-charge ratios for the fragment ions predicted from amino acid sequences obtained from the database and the fragment ions observed

The vapors of tetradecane (C14H30) were ionized by an electron bombardment method. Fragment ions such as C3H7, C6H13 and C12H25 ions were separated by E B filter (Wien filter), and accelerated toward the Si(100) substrates. Thickness measurement showed that thin films were deposited on the Si

violating chemical constraints. However, these methods cannot be well generalized to the component prediction of fragment ions in tandem mass spectra. In this paper, a new method, FFP (Fragment ion Formula Prediction), is presented to predict elemental component formulas of fragment ions. In the FFP method

The mass spectra for both horizontal and vertical polarizations and the angular distributions of fragment ions arising from Coulomb explosion of tetrahedral methyl iodide (CH 3 I) ions, obtained at a laser intensity of 10 16 Wcm -2 are presented. All fragment ion distributions are peaked along

An apparatus has been constructed to study the kinetic energies of fragment ions SFn+ (n = 1–5) produced by electron impact on SF6 molecules. The retarding curves of the ions were produced by using a retarding field analyser of einzel lens type [1], and the second derivative method was employed

Application Note It is widely accepted that high precursor ion mass measurement accuracy significantly improves confidence in MS/MS database search results through the reduction of false positives. In contrast, the impact of high fragment ion mass accuracy has been largely ignored. The Agilent

(CH2) units and fullerene (C60) molecule

We have applied conformer-selective infrared-ultraviolet (IR-UV) double-resonance photofragment spectroscopy at low temperatures in an ion trap mass spectrometer for the spectroscopic characterization of peptide fragment ions. We investigate b- and a-type ions formed by collisioninduced

composition of fragment ions and thereby facilitate the structural characterization of metabolites. The software tool FragExtract was developed and evaluated with LC-HRMS/MS spectra of both native 12C- and uniformly 13C (U-13C)-labeled analytical standards of 10 fungal substances in pure solvent and spiked

the construction of fragment ion library for Amadori-modified lysine (AML), N()-(car-boxymethyl)lysine (CML)-, and N()-(carboxyethyl)lysine (CEL)-modified peptides of the corresponding syntheti-cally modified albumin using high resolution accurate mass spectrometry (HR/AM). The glycated peptides were manually