Survey of selected hydrides as doping agents for a hydrogen-atmosphere flame-ionization detector
✍ Scribed by M.D. Dupuis; H.H. Hill Jr.
- Book ID
- 104144942
- Publisher
- Elsevier Science
- Year
- 1980
- Tongue
- English
- Weight
- 666 KB
- Volume
- 195
- Category
- Article
- ISSN
- 1873-3778
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✦ Synopsis
The hydrogen-atmosphere frame-ionization detector for gas chromatography exhibits a selective and enhanced response for metal containing compounds when its atmosphere is doped with small amounts of silane. In this study, response characteristics of the flame were investigated for a variety of organic compounds when the hydrogen atmosphere was doped with small amounts of methane, silane, germane, or phosphine. Response of pure hydrocarbons and compounds containing F, Cl, 0, S, N, P, As, Sb, Si, or Ge were either unaffected by the addition of doping agents, or their variations were not considered analytically sign&ant. As expected, compounds of Fe, Sn and Pb exhibited enhanced responses with silane doping. MO and W compounds showed increased ionization with methane. Several compounds increased response with the introduction of germane, but noise also increased such that no gain in signal-to-noise ratio was obtained_ Phosphine proved to be the doping agent with the most potential. Response intensities for compounds containing Fe, Sn, Pb, MO and Sb appeared analytically useful, but more signifkant, was the fact that the peaks were negative. Thus, it appears that a potential exists for the development of a phosphine-doped detector in which compounds not containing elements of interest would produce deminutive positive peaks while metal containing compounds would respond with enhanced negative peaks. Further studks on this mode of operation are recommended. When properly optimized, a hydrogen-atmosphere frame-ionization detector (HAFID), constructed from a commercial flame-ionization detector WD), is capable of detecting sub-picogram quantities of certain metal compounds with selectivities against hydrocarbons gre&er than IO5 (ref. I)_ Direct gas chromatographic (SC) determinations of antiknock agents, tetraethyllead and methykyclopentadieneylmanganese, in gasolines have recently been demonstrated2.
Operation of an HAFID difXers from that of an FID in that the oxident (&r, enriched with oxygen) is introduced to the flame with carrier gas while the fuel @yd.rogen, doped with small amounts of silane) is brought direct& into the detector