The essential oil in leaves of Polygonum minus Huds., a local aromatic plant, were identified by a pipeline of gas chromatography (GC) techniques coupled with mass-spectrometry (MS), flame ionization detector (FID) and two dimensional gas chromatography time of flight mass spectrometry (GC x GC-TOF MS). A total of 48 compounds with a good match and high probability values were identified using ...

We present a quantum solution to the electron spin decoherence by a nuclear pair-correlation method for the electron-nuclear spin dynamics under a strong magnetic field and a temperature high for the nuclear spins but low for the electron. The theory incorporates the hyperfine interaction, the intrinsic both direct and indirect nuclear interactions, and the extrinsic nuclear coupling mediated b...

Pulsed NMR is the most convenient and powerful technique for measuring diffusion, when it is applicable. Hahn (1) in a seminal paper laid the foundations of the technique. He showed that for a nuclear spin system that obeyed the Bloch equations (taking small liberties with exact details), a 9O.y T 180, RF pulse sequence produced a free induction decay (FID) and an echo, as pictured in Figure 1....

A very simple, rapid and sensitive dispersive liquid-liquid microextraction (DLLME) followed by gas chromatography and flame ionization detection (GC-FID) was developed for the determination of phenol and carvacrol in honey samples. A mixture of 100 μl dichloromethane (extraction solvent) and 0.5 ml acetonitrile (disperser solvent) was rapidly injected into sample solution. Thereby a cloudy sol...

as a test case to examine the roles of phonology and morphology in the spelling process. We introduced university students to novel meanings of spoken forms, for example, presenting /fid/ as a rare word 10 for a type of furniture. We asked whether participants avoided spelling the new word as ‹feed›, instead using alternatives such as ‹fead›. Although participants produced some alternative spel...

The determination of residual solvents in pharmaceuticals is one of the most important gas chromatography (GC) applications in quality assurance/quality control (QA/QC) in the pharmaceutical industry. Sample introduction is normally done using static headspace (SHS). In routine QC, GC with flame ionization detection (FID) is preferred, while mass spectrometry (MS) can be used for screening and ...

Behavioural responses can help species persist in habitats modified by humans. Roads and traffic greatly affect animals' mortality not only through habitat structure modifications but also through direct mortality owing to collisions. Although species are known to differ in their sensitivity to the risk of collision, whether individuals can change their behaviour in response to this is still un...

In this study, two methods are developed for the extraction of 1,4-dioxane (dioxane) from water using 80-microm carboxen-polydimethylsiloxane solid-phase microextraction fibers followed by either gas chromatography (GC)-flame ionization detection (FID) or GC-mass spectrometry (MS). With GC-FID, the lower limit of detection (LOD) for 1,4-dioxane is 2.5 microg/L (ppb) with a linear range of 5 to ...

We introduce a new in-situ instrument, Thermal desorption Aerosol GC/MS-FID (TAG), capable of hourly measurements of speciated organic compounds in atmospheric aerosols. Aerosol samples are collected into a thermal desorption cell by means of humidification and inertial impaction. The sample is thermally desorbed and transferred with helium carrier gas into a gas chromatography (GC) column, wit...