Properties of High Boiling Petroleum Products

Abstract

ANDThe only methods heretofore described for predicting carcinogenic activity have been limited to series of pure aromatic compounds or to high]>-specialized types of petroleum products. After examination of a number of different reactions and properties of polycyclic aromatic compounds, five nonbiological methods have been developed for the prediction of tumor potency of high boiling petroleum products. Each method gave about the same degree of correlation with biological data. These physical-chemical methods are all based upon measurements of certain types of polycyclic aromatic hydrocarbons. The results support the premise t h a t the carcinogenicity is a function qf the concentration of these types of compounds in oils. The methods, therefore, obviate the necessity of isolating or analyzing the actual carcinogenic compounds. The caffeine number method is preferred for routine analytical work. It is based upon a n ultraviolet examination of a n aqueous caffeine extract of the aromatic hydrocarbons. A standard deviation of 8.4 was obtained for the difference between the predicted and the biological tumor potency values of 123 different products. Reproducibility of the caffeine number was better than t h a t of the biological data. Comprehensive analytical data for all five methods are presented for a variety of high boiling petroleum products. These demonstrate t h a t a choice of methods is available, depending upon the particular types of products to be analyzed and the facilities a t hand.

Organic Polarography

“…The method has been used to analyze indene and coumarone fractions (330), is suitable for the determination of anthracene in coal tar products (128) and for predicting tumor potencies of high-boiling petroleum fractions (84), and has been used to follow the alkaline condensation of indene with benzaldehyde (331).…”

Reducing Carcinogenicity of High Boiling Petroleum Products

“…Other authors (10, 11, 14) have demonstrated that the carcinogenic activity of certain polycyclic aromatic hydrocarbons can be inhibited by the presence of other similar hydrocarbons. The possible inhibitory effects of certain nonhydrocarbon components (probably oxygenated) of high boiling petroleum fractions have been noted (8). These observations all point to the possibility of finding effective additives for inhibiting carcinogenic activity in oils.…”

“…191) was hydrogenated to take up about 1 mole of hydrogen per mole of oil, using a commercial nickel tungsten sulfide catalyst at 2500 pounds per square inch for 15 hours at 250°C. The biological tumor potency of the oil Obtained by high aromatics characterization procedure (8) Table II was reduced from 55 to 45 by the treatment. This result indicated that, in order to effect a large reduction in potency, the hydrogen consumption should be increased.…”

“…Although some of the methods appear to be effective and practical, the present results are regarded as preliminary for, aside from possible economic limitations, they cannot be recommended without qualification until they have been widely tested with the large variety of high boiling products normally encountered in modern refining operations. The numerical values of tumor potency used for the quantitative expression of carcinogenicity are defined in a companion paper (8).…”

Review - Petroleum

“…Hess and Arnold (70) separated naphthalene and more highly condensed systems from monocyclic and alkylated monocyclic aromatics in cycle gas oils by reaction with tetrahalophthalic anhydride to form a solid adduct. Ebv, Priestley, Rehner, and Hall (39) proposed five physical-chemical methods for determining polycyclic aromatic hydrocarbons in high boiling petroleum products to provide nonbiological methods for predicting carcinogenic activity. These methods include ultraviolet absorption of a 343°to 538°C.…”