Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Electron-capture detectors, lead analysis

Analysis of the halohydrocarbons, halocarbons, and sulfur hexafluoride is usually achieved by gas chromatography that is equipped with an electron capture detector. Complex metal anions, such as cobalt hexacyanide, are used as nonradioactive tracers in reservoir studies. The cobalt in the tracer compound must be in the complex anion portion of the molecule, because cationic cobalt tends to react with materials in the reservoir, leading to inaccurate analytic information [1226]. [Pg.226]

A glas tube (diameter 0.8 cm), filled successively with the following reagents, was used as a reactor 3 cm of silver nitrate on diatomite (1 1), 2cm of sulphuric acid on diatomite, and 1 cm of disodium phosphate on diatomite. Each layer in the reactor was separated from the next with a small layer of diatomite brick. The reactor was placed before the separating column (LSP Twin-60). At room temperature 2-bromobutane is absorbed quantitatively by the layer of silver nitrate, and 1 -bromo-2-methylpropane does not react with it. The use of a reactor containing silver nitrate for absorbing dichloro-ethane and dibromoethylene in the GC analysis of methyl and ethyl compounds of lead in petrols using an electron-capture detector has been described [92]. [Pg.176]

Kramer used an electron capture detector for the determination of lead alkyls in petroleum. He claims that a complete analysis for tetramethyllead and tetraethyllead in petrol can be achieved on a column (3 metres) of 10% of Apiezon L on Chromosorb W at 120°C with bromobenzene as internal standard. To separate the mixed alkyls (ethyltrimethyllead, diethyldimethyllead and triethylmethyHead, tetramethyllead and tetraethyllead) it is necessary to combine the above analysis with use of a pre-column (5 cm) of 20% of Carbowax 400 saturated with silver nitrate on Chromosorb W impregnated with 8% of potassium hydroxide. The pre-column retains halogen-containing scavengers in the petrol, which would otherwise mask the ethyltrimethyllead peak. As little as 0.002 g of tetramethyllead and tetraethyllead can be detected in 1 litre of petroleum in a 45 minute analysis. [Pg.404]

Dual Detectors. Most dual detectors are run in parallel, the column effluent being split and run through both of them simultaneously. In GC the technique is known as dual channel GC usually, one of the detectors chosen is universal and the other is highly selective. Figure 6.6 shows the analysis of a commerical gasoline sample with dual detection by flame ionization (FID) and electron capture (ECD). The FID detects all the hydrocarbons, but the ECD is selective for the alkyl lead additives in gasoline and permits their detection without interference from the hydrocarbons. [Pg.49]


See other pages where Electron-capture detectors, lead analysis is mentioned: [Pg.1047]    [Pg.377]    [Pg.40]    [Pg.1600]    [Pg.141]    [Pg.103]    [Pg.370]    [Pg.371]    [Pg.376]    [Pg.398]    [Pg.450]    [Pg.93]   
See also in sourсe #XX -- [ Pg.17 ]




SEARCH



Analysis detectors)

Detector electron capture

Electron analysis

Electron detectors

Electronic detectors

© 2024 chempedia.info