PNA analysis

PNA analysis a method of analysis for paraffins, naphthenes, and aromatics. 

TABLE 3-15. Representative Paraffin, Naphthene, and Aromatic (PNA) Analysis of a Middle Distillate Fuel by Mass Spectroscopy... 

UV-Absorption Spectrometry to PNA Analysis, Appl Spectro. (1978) in press. 

The cracking and hydrogenation balance in the catalyst depends on acid center/metal ratio. In our case, the main target is the diesel quality. The results of diesel PNA analysis are shown in Table 6 for catalysts Cl, CII and CIII operating at 380 °C. The analysis shows that the steam-ammonia treatment increases the paraffins content and decreases naphthenes and aromatics content. This indicates a higher hydrogenation-hydrogenolisis activity in CIII than in CII and Cl. In addition, the NMR analysis indicates... 

Levels of polynuclear aromatic hydrocarbons (PNAs) reported in this work for marine organisms, foodstuffs, sediments, and wastewater streams were found to be in the low ppb range. Data obtained on sediments and shellfish indicate that these PNAs are not petroleum derived but arise from a higher temperature combustion source. This conclusion is based on the alkyl-substituted PNAs measured relative to the parent PNAs. Analytical methods applicable to PNA analysis are almost as varied as the number of laboratories doing-this type of work. This chapter describes the Exxon methods as they apply to various environmental samples. 

Analytical methods applicable to PNA analysis are almost as varied as the number of laboratories doing this type of work. An attempt will be made here to summarize the more pertinent techniques and to review their applicability to various types of environmental samples. 

The collected samples from both of the above studies were extracted with dichloromethane (DCM) and sent for PNA analysis to 1) Oak Ridge National Laboratory for SL and RTP analysis,... 

A detailed PNA analysis of the symmetric stretching mode of the methyl functional group on the butyl chain of the cation and the methyl group from the methyl sulfate anion signal intensity determined minima at 2° 3° for the methyl... 

As such a high resolution is not always required for PNA analysis the flow rate through the Molsieve 13X column can be increased by a factor of 4-8 which will reduce analysis time to about 7-8 minutes. Overloading phenomena will occur quite soon on this type of Molsieve 13X ALOT column due to the low capacity. 

A method for a more complete analysis of all of the components was developed by Boer and Van Arkel (90). A three-column system with automatic valve switching and cold traps was utilized to determine paraffins, naphthenes, and aromatics. Thus it is commonly referred to as a PNA analysis. A polar column of tris(cyanoethyl)nifromethane was used to retard the aromatics. A 13X molecular sieve column then separated the paraffins and naphthenes. A nonpolar column of UCCW-982 provided further separation of the aromatics and naphthene components. Fignre 13.31 shows a typical chromatogram along with an indication of the column switching involved. 

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