Font Size: a A A

Small stoichiometric flames for the gas chromatographic determination of organometallics

Posted on:1997-04-23Degree:Ph.DType:Dissertation
University:Dalhousie University (Canada)Candidate:Lowery, Nancy BelleFull Text:PDF
GTID:1461390014981789Subject:Chemistry
Abstract/Summary:
A small, stoichiometric name for a commercial gas chromatographic-flame photometric detector has been investigated using a variety of main group and transition elements. It was highly successful for the determination of most of the organometallic compounds, improving detection limits in almost all cases.;In addition to changes in traditional flame-gas flows, modifications were made to the same flame photometric detector so that a larger fraction of its luminescence would reach the photomultiplier tube. Tests with compounds of lead and osmium resulted in up to fifty times enhanced light transmission. Because of the square-root dependence of quantum noise, the signal-to-noise ratios improved about sevenfold.;To this modified version of the flame photometric detector was added a second channel, so that there would be two channels, with high sensitivity, operating simultaneously. Two alternate designs for the secondary channel were tested with compounds of osmium, lead, sulfur and phosphorus. Both the new primary channel and either one of the two second-channel designs yielded higher light throughput and lower detection limits than the original, conventional channel.;Using the stoichiometric flame and the two major modifications, a number of organometallic compounds were determined with detection limits that were significantly better than could be detected with conventional name photometric techniques. In addition, Si, W, MB and Bi, previously undetected using gas chromatographic-flame photometric detection, were found to respond favorably to these new conditions.
Keywords/Search Tags:Gas, Flame, Photometric, Stoichiometric, Using, Detection
Related items