This article describes the strange behavior of the widely used herbicide metolachlor under chemical ionization conditions in a hybrid source ion trap mass spectrometer in gas chromatography/mass spectrometry (GC/MS) coupling. With the use of ammonia as the reagent gas, metolachlor provides a chlorinated ion at m/z 295/297, almost as abundant as the protonated molecule at m/z 284/286, which cann...

Computer control of time delay of the extraction of ions from the ion source of the TOF mass spectrometer is presented. Owing to the computer, the user has the full control of power parameters and ion current delay, which is about microseconds.

MOTIVATION Effective use of proteomics data, specifically mass spectrometry data, relies on the ability to read and write the many mass spectrometer file formats. Even with mass spectrometer vendor-specific libraries and vendor-neutral file formats, such as mzXML and mzData it can be difficult to extract raw data files in a form suitable for batch processing and basic research. Introduced here ...

Development of two new techniques for studying the gas phase chemistry of negative ions is reported. Collision induced dissociation (CID) of (M-1)- ions has been accomplished in a newly constructed triple stage quadrupole mass spectrometer. This instrument was assembled by adding two additional Finnigan quadrupole mass filters to a Finnigan Model 3200 CI mass spectrometer. Generation of (M-1)- ...

2014 It has been shown recently that fast heavy ions can induce a mild desorption of organic molecules deposited on a thin foil, when passing through the foil. A time of flight mass spectrometer, originally developed to identify the mass of radioactive nuclei, has been slightly transformed to allow the determination of the mass of large molecules. The desorption of the molecules is at the prese...

We present a newly developed macromolecular ion accelerator mass spectrometer that combines a dual-ion-trap device and a macromolecular ion accelerator (MIA) to achieve the capability of analyzing samples with a mixture of large biomolecules. MIA greatly increases detection efficiency. The dual ion trap includes a quadrupole ion trap (QIT) and a linear ion trap (LIT) in tandem. The dual ion tra...

We evaluated the Hewlett-Packard 5995B benchtop capillary gas chromatograph-mass spectrometer (GC-MS) for its ability to identify drugs commonly detected and (or) measured in the clinical toxicology laboratory. Initial experiments indicated that the instrument as originally configured, with an isolation valve between the gas chromatograph and mass spectrometer, was unsatisfactory for the identi...

1.1 Route to Market: Discovery and Development of New Drugs 2 1.1.1 Industry Research and Development 2 1.1.2 Drug Discovery and Development Process 4 1.1.2.1 Drug Discovery 5 1.1.2.2 Drug Development 7 1.1.2.2.1 The Drug Substance 7 1.1.2.2.2 Clinical Trials 8 1.2 Drug Metabolism and Pharmacokinetics in Drug Discovery and Development 10 1.3 Mass Spectrometry Fundamentals 11 1.3.1 History 12 1....

6 Contents Introduction The advantage of radioisotopic standards compared to other physical standards is the independence of their properties from outer conditions. They are neither sensitive to temperature change nor to progress of time. They serve as influence-free-etalon. That is why their use is advantageous in fundamental research, where high precision is required. For instance in direct n...