This overview evaluates the capabilities of mass spectrometry (MS) in combination with gas chromatography (GC) and liquid chromatography (LC) for the determination of a multitude of pesticides. The selection of pesticides for this assessment is based on the status of production, the existence of regulations on maximum residue levels in food, and the frequency of residue detection. GC-MS with el...

Molecular clouds at the Galactic center (GC) have environments considerably different from their disk counterparts. The GC may therefore provide important clues about how the environment affects star formation. Interestingly, while the inner 50 parsecs of our Galaxy include a remarkable population of high-mass stars, the initial mass function (IMF) appears to be consistent with a Salpeter slope...

Comprehensive chemical information is needed to understand the environmental fate and impact of hydrocarbons released during oil spills. However, chemical information remains incomplete because of the limitations of current analytical techniques and the inherent chemical complexity of crude oils. In this work, gas chromatography (GC)-amenable C9-C33 hydrocarbons were comprehensively characteriz...

Atmospheric pressure chemical ionization-tandem mass spectrometry (APCI-MS/MS) was applied for the first time to the direct analysis of octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5) in gaseous matrixes without extraction or prior chromatographic separation. Mass spectrometric characteristics of both compounds under APCI conditions and their fragmentation behavior in MS...

PURPOSE To compare the effect of vitamin K(2) and risedronate on trabecular bone in glucocorticoid (GC)-treated rats. MATERIALS AND METHODS Forty-eight Sprague-Dawley female rats, 3 months of age, were randomized by the stratified weight method into 5 groups according to the following treatment schedule: age-matched control, GC administration, and GC administration with concomitant administra...

OBJECTIVE Adverse body compositional features and low bone mineral density (BMD) are the characteristic of patients with active Cushing's syndrome (CS). The aim of this study was to evaluate body composition and BMD in women with CS in long-term remission and the influence of polymorphisms in genes affecting glucocorticoid (GC) sensitivity on these end-points. DESIGN, PATIENTS AND METHODS Thi...

Maleimides (1H-Pyrrole-2,5-diones) are monopyrrolic pigment derivatives with specific alkyl side chains that can be directly linked to their tetrapyrrole precursors, most notably chlorophylls and bacteriochlorophylls. These compounds can be used as palaeoenvironmental indicators such as algal productivity and redox conditions in ancient and modern aquatic systems. Here, we present a new method ...

Gas chromatography/mass spectrometry (GC/MS) of the MOD flake Micro-samples (3.3 mg from the MOD flake and less than 1 mg from the other samples, see below) were collected from the specimens and submitted to an analytical procedure (GC/MS) in order to identify lipids, waxes, proteins, resinous materials and saccharides [1-2]. GC/MS had already been successfully employed for the characterization...