Effective carbon number , flame

Effective carbon number (ECN), flame ionization detection, 689, 690, 708 EHS (extremely hazardous substances), 744 Elastomers... 

This reaction is an almost quantitative counter of carbon atoms being burned. For hydrocarbons, this means that flame response is proportional to the number of carbon atoms, rather than weight or moles. Compounds with heterogroups on some of the carbon atoms lose some of their ability to form CH. This is usually corrected for by considering the effective carbon number, that number which would account for the compound s response. 

Accurate g.l.c. analysis of mixtures of substances with a flame ionization detector (f.i.d.) depends upon a knowledge of the relative detector response of each compound. Variations in the f.i.d. responses of steroids in molar terms have now been put on a quantitative basis. There is a good linear relationship between molar f.i.d. response and the effective carbon number , which is the number of carbon atoms per molecule less half the number of oxygen atoms (over the ranges Ci8—C31, and Oo—O4). This behaviour parallels earlier conclusions for paraffin hydrocarbons, alcohols, and esters. G.l.c. data are reported for the trimethylsilyl ethers of 49 plant sterols on eight different columns. ... 

Effective Carbon Numbers calculated using Table I, p. 336, of Calculation of Flame Ionization Detector Relative Response Factors Using the Effective Carbon Number Concept by Scanlon and Willis. Journal of Chromatographic Scieiue, Vol 23, August 1985, p. 333-339... 

Jones, F. W., Flame ionization detector relative response factors for oligomers of alkyl and aryl ether polyethoxylates using the effective carbon number concept, 7. Chromatogr. Sci., 1998,56,223-226. 

Mixtures of O-methyl ethers obtained by partial methylation of a number of methyl glycopyranosides have been acetylated and the products identified by g.l.c.-m.s. The use of partially ethylated alditol acetates for the analysis by g.I.c. of the components of polysaccharides has been described. The ethyl analogues are eluted before the corresponding methyl derivatives, and this often allows the separation of many polysaccharide components by g.l.c. that are not separable as their partially methylated alditol acetates. The use of molar flame-responses calculated on the basis of effective carbon responses has been advocated for the accurate determination of partially methylated and partially ethylated alditol acetates by g.I.c. ... 

For environmental reasons, burning should be smokeless. Long-chain and unsaturated hydrocarbons crack in the flame producing soot. Steam injection helps to produce clean burning by eliminating carbon through the water gas reaction. The quantity of steam required can be as high as 0.05—0.3 kg steam per kg of gas burned. A multijet flare can also be used in which the gas bums from a number of small nozzles parallel to radiant refractory rods which provide a hot surface catalytic effect to aid combustion. 

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