Hydrocarbon group-type analysis

J. A. Apffel and H. McNair, Hydrocarbon group-type analysis by on-line multidimensional chromatography. II. Liquid chromatography - gas chromatography , J. Chromatogr. 279 139-144 (1983). 

Y. -H. Seo, K. -H. Lee and D. -H. Shin, Investigation of catalytic degradation of HDPE by hydrocarbon group type analysis, J. Anal. Appl. Pyrolysis, 70, 383-398... 

Suatoni, J. C., Swab, R. E., "Rapid Hydrocarbon Group-Type Analysis by... 

Sharma, B.K., Sarowha, S.L.S. Bhagat, S.D., Tiwari, R.K., Gupta, S.K., Venkataramani, O.S., (1998), Hydrocarbon group type analysis of petroleum heavy fractions using the TLC-FID technique, /, Anal Chem., 360, 539-544. 

Table VIII. Group-type Analysis of P.R. Spring Saturated Hydrocarbons...

Because of the estimated (or real) number of isomers in this carbon number range (Table 7.2), complete speciation of individual hydrocarbons is not possible for middle distillates. Compositional analysis of middle distillates is obtained in terms of hydrocarbon group type totals. These groups are most often defined by a chromatographic separation. 

Petroleum group type analysis (not suitable for risk estimation) Group type analyses are performed to measure the amounts of individual petroleum classes of hydrocarbons (e.g. saturates, aromatics, polars). This type of measurement is typically used for heavier fractions and can be used to interpret or identify the type of oil (Fig. 6.5). 

Group type analysis methods are designed to separate hydrocarbon mixtures into classes such as saturates, aromatics and polars. As described previously,... 

As already mentioned, it is the volatile constituents that serve to identify fruit type and variety. Broadly speaking, qualitative analysis will identify the principal substances present in the volatiles fraction as representative of a particular fruit type, but it is the relative proportions of these substances that will reflect the variety. Alcohols, volatile acids, esters, carbonyl compounds, and low-boiling hydrocarbons are the principal groups represented. Analysis by GC-MS (gas chromatography coupled with mass spectroscopy) can be used to provide quantification and identification of the various constituents. 

N. G. Johansen, L. S. Ettre and R. L. Miller, Quantitative analysis of hydrocarbons by structural group type in gasolines and distillates I. Gas chromatography, J. Chro-matogr., 256, 393-417 (1983). 

In this tiered analytical approach, the high resolution capillary GC-FID analysis is applied to evaluate hydrocarbon groups (including TPH, UCM, the total saturates and total aromatics), to determine concentrations of n-alkanes and major isoprenoid compounds, and to characterize the product types in fresh to highly weathered oil samples. The GC -MS analysis provides data on the source specific marker compounds including the target alkylated PAH homologues and other... 

Hayes, P. C., Jr. and Anderson, S. D., The Analysis of Hydrocarbon Distillates for Group Types Using HPLC with Dielectric Constant Detection A Review, Jouma/ of Chromatographic Science. Vol. 26, 1988, pp. 210-217. 

Figure 13.22 shows the resolution of the surfactants Tween 80 and SPAN. The high resolution obtained will even allow the individual unreacted ethylene oxide oligomers to be monitored. Figure 13.23 details the resolution of many species in both new and aged cooking oil. Perhaps the most unique high resolution low molecular weight SEC separation we have been able to obtain is shown in Fig. 13.24. Using 1,2,4-trichlorobenzene as the mobile phase at 145°C with a six column 500-A set in series, we were able to resolve Cg, C, Cy, Cg, C9, Cio, and so on hydrocarbons, a separation by size of only a methylene group. Individual ethylene groups were at least partially resolved out to Cjg. This type of separation should be ideal for complex wax analysis.

Because E -constants for complex groups are obtainable at present only by an empirical procedure82 a corresponding analysis is not possible for aryl-, vinyl-, and other nonflexible a-type radicals. This difficulty was overcome recently by the development of a new set of steric substituent parameters. 9f for front strain phenomena. These constants are defined as the difference in heat of formation for the hydrocarbons 30 and 31. The heats of formation are calculated for this purpose by... 

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