Search results
Results from the WOW.Com Content Network
You are free: to share – to copy, distribute and transmit the work; to remix – to adapt the work; Under the following conditions: attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses ...
In the petroleum refining and petrochemical industries, the initialism BTX refers to mixtures of benzene, toluene, and the three xylene isomers, all of which are aromatic hydrocarbons. The xylene isomers are distinguished by the designations ortho – (or o –), meta – (or m –), and para – (or p –) as indicated in the adjacent diagram.
The detection limit for electron capture detectors is 5 femtograms per second (fg/s) and the detector commonly exhibits a 10,000-fold linear range. [ citation needed ] This made it possible to detect halogenated compounds such as pesticides and CFCs , even at levels of only one part per trillion ( ppt ), thus revolutionizing our understanding ...
An annular dark-field image taken may be complementary to a bright-field image constructed from the captured CBED images. The use of a hollow detector with a hole in the middle can allow for transmitted electrons to be passed to an EELS detector while scanning. This allows for the simultaneous collection of chemical spectra information and ...
The photoionization detector was applied to gas chromatography (GC) three years later, in 1976. [5] A PID is highly selective when coupled with a chromatographic technique or a pre-treatment tube such as a benzene-specific tube. Broader cuts of selectivity for easily ionized compounds can be obtained by using a lower energy UV lamp.
The conventional secondary electron detector of SEM (Everhart–Thornley detector) cannot be used in the presence of gas because of an electrical discharge (arcing) caused by the kilovolt bias associated with this detector. In lieu of this, the environmental gas itself has been used as a detector for imaging in this mode:
Benzene is a natural constituent of petroleum and is one of the elementary petrochemicals. Due to the cyclic continuous pi bonds between the carbon atoms, benzene is classed as an aromatic hydrocarbon. Benzene is a colorless and highly flammable liquid with a sweet smell, and is partially responsible for the aroma of gasoline.
A chemical file format is a type of data file which is used specifically for depicting molecular data. One of the most widely used is the chemical table file format, which is similar to Structure Data Format files. They are text files that represent multiple chemical structure records and associated data fields.