This is the conventional mode of operation for a magnetic sector mass spectrometer utilizing an array detector.
Two different kinds of mass spectrometers were utilized in this study: nanospray (NSI /LTQ FT (Thermo Finnigan) and matrix assisted laser desorption ionization (MALDI /TOF/TOF (Applied Biosystems).
This laboratory has recently reported the construction and characterization of a linear time-of-flight mass spectrometer (ToF-MS) utilizing a radio frequency glow discharge ionization source.
A TSQ Vantage triple-quadrupole mass spectrometer (Thermo Fisher Scientific, San Jose, CA) was utilized for the scheduled LC-MRM analysis with on-the-fly correction for retention time (RT) shift.
A Quattro Premier XE tandem mass spectrometer from Waters-Micromass was utilized for analyte detection.
Chemical analyses utilized a quadrupole mass spectrometer (QMS) to perform pyrolysis-evolved gas analysis (EGA) and gas chromatography mass spectrometry (GC/MS) both with and without derivatization, as well as laser desorption mass spectrometry (LD/MS) techniques.
To perform MS, Waters Q-TOF Premass maspectrometerter system (Micromass MS Technologies, Manchester, UK) was utilized with operating conditions as; V-mode, resolution (above 32000 mass), scan time (1.0 min), collision gas (argon at a pressure of 5.3 × 10−5 Torr) and inter-scan delay (0.02 s).
MS detection utilized micrOTOF-QII mass spectrometer (Bruker, Bremen, Germany).
Because isotopes differ in mass, their relative abundance can be determined if the masses are separated in a mass spectrometer (see below Use of mass spectrometers).
When utilizing a Finnigan mass spectrometer (with a heated capillary interface design), the signal gain with the nanosplitter ranged from 5 to 16 times the peak area obtained using the conventional interface without splitting.
Mass spectrometric analyses of tryptic peptides were carried out on a MALDI VOYAGER DE-PRO time of flight mass spectrometer from PerSeptive BioSystems (Framingham, MA) utilizing a nitrogen laser, emitting at 337 nm, and an accelerating voltage of 25 kV.
