Saturate group-type analysis

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

In general terms, group-type analysis of petroleum is often identified by the acronyms for the names PONA (paraffins, olefins, naphthenes, and aromatics), PIONA (paraffins, Ao-paraffins, olefins, naphthenes, and aromatics), PNA (paraffins, naphthenes, and aromatics), PINA (paraffins, Ao-paraffins, naphthenes, and aromatics), or SARA (saturates, aromatics, resins, and asphaltenes). However, it must be recognized that the fractions produced by the use of different adsorbents will differ in content and will also be different from fractions produced by solvent separation techniques. 

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,... 

Applications On-line pSFC-GC has been applied to the analysis of fossil fuels, such as group-type separations of high-olefin gasoline (saturates, olefins and aromatics) [930]. No significant applications concerning polymer/additive analysis can be mentioned. 

The racemic mixture of 36 crystallized as a racemic compound in an achiral space group crystal. Analysis of its X-ray crystallographically determined structure shows one of the enantiomers to have a reference,S)-TCBtype33 conformation as depicted in the iconic drawing for 36 (see Fig. 19). Conformational families exist for cis-3 or trans-44 cyclononenes. The various members of a family maintain similar torsion angles for six of the nine bonds compared to those measured for their cyclononane saturated parent.3 Double bonds are formed from either synclinal or antiperiplanar-type bonds in the parent. Conversion of a single bond to a double bond will usually... 

The fatty acyl substituents were mainly of three types saturated straight-chain C,6-C,9 acids C21-C25 mycosanoic acids and C24-C28 mycolipanolic acids. Analysis of one of the major 2,3-di-O-acyltrehaloses by two-dimensional H-chemical-shift-correlated and H-detected heteronuclear multiple-bond correlation spectroscopy established that the C18 saturated straight-chain acyl group was located at the 0-2 position and that the C24 mycosanoyl substituent was at the 0-3 position of the same nonglycosylated terminus (structure 8). At least six molecular... 

Figure 33.2 shows XPS spectra of the surfaces of the TMS plasma polymer film deposited on (Ar + H2) plasma-pretreated steel (a, b, c) and on O2 plasma-pretreated steel (d, e, f). As shown in the spectra, the surface of the plasma film is functional in nature with functional groups of C-OH, C=0, and Si-OH. Two films basically ended up with the same surface structure. This is also confirmed by XPS analysis of the film during the film aging in air after the film deposition, which indicated that the film surfaces were saturated with a fixed surface structure after a few hours of air exposure [4]. This is due to a well-known phenomenon that the residual free radicals of the plasma polymer surface reacted with oxygen after exposure to air [5]. Curve deconvolution of C Is peaks showed structures of C-Si, C-C, C-0, and C=0. The analysis clearly shows a silicon carbide type of structure, which is consistent with the IR results. The functional surfaces of TMS films provide bonding sites for the subsequent electrodeposition of primer (E-coat). 

Figures 4 and 5 present the difference between the DTG curves obtained for samples after adsorption of acetaldehyde at saturation conditions and the initial ones. Analysis of the shapes of the curves indicates that at least two types of interactions exist. They are represented by two peaks, which partially overlap. The first one, centered about 373 K likely represents weak interactions of acetaldehyde with functional groups via hydrogen bonding. The presence of mesopores on the surface results also in such a weak adsorption since these interactions are not energetically favorable. Moreover, the surface acidic sites present mainly on the unmodified and...

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