V O L U M E 28, NO. 2, F E B R U A R Y 1956 large excess of water. Another reason may be that the anilinesulfonic acid complex is stable b u t it is made more soluble in the aniline-chloroform medium with increased amounts of water. When analyzing plant sow oil samples, the amounts of sulfuric a n d sulfonic acid present in a sample are much less than those used in these experiments. For plant samples, the 0.4 ml. of water recommended in the procedure gives a mole ratio of water to total acids of about 20 to 1.
227 About eight samples can be analyzed in 1 man-day; the easeand rapidity of determination make this method a desirable one for plant control. T h e estimation of plant yields of finished product based on sulfonic acid values agrees well with yields actually obtained. The determination of the small amounts of sulfuric acid in the sour oil layer has made it possible to follow desalting operations. QCKNOWLEDGMENT
con-cLusIo>s
T h e data obtained have shown that the determination of sulfuric and sulfonic acids in sour oils is possible. Sulfur dioxide does not interfere in the determinations. RIinimum water requirement studies have shown that controlling the mole ratio of water to sulfuric acid, as previously reported ( f O ) , is not the determining factor in obtaining good results. T h e water requirements are higher, mainly because of the presence of sulfonic acids. More work is needed t o determine the elact rolc the amount of water plays in this determination. It is believed t h a t the aniline precipitation procedure described here can be used t o determine not onlv sulfuric acid in acid sludges, as suggested bj- Weiss and others (fa),but for sulfonic acids as well. If the equivalent w i g h t of the sulfonic acid is k n o w and there is negligible sulfuric acid ester present, this method should be applicable t o both acid sludgep and spent acids. I t should be pal ticularly useful on alkylarenesulfonic acids. T h c authors have successfully analyzed a large number of “green acids”-Le., the bottom layer produced during the sulfonation of lubricating oils-for both of these constituents. For this type sample about 1 gram is taken. Typical analyses would be 15% sulfuric and 609; siilfonir acids.
The authors wish to express their thanks to the Sun Oil Co. for the privilege of publishing this paper and to acknowledge the help of Paul Congdon. LITERATURE CITED
(1) Am. SOC.Testing Materials, D 855-52T, ‘Standards on Petroleum Products and Lubricants,” (D-2), p. 335, 1954. ( 2 ) Bacon, F. S., IND.Ero. CHEM.,AXAL.ED. 1, 89 (1929). (3) Barr, T., Oliver, J., and Stubhings, W. V., .J. SOC.Chem. Ind. 67, 45 (1938). (4)Brooks, F., Peters. E. D., and Lykken, L.. ISD. ENG.CHEM., A N A L . ED. 18, 544 (1946). ( 5 ) Epton, S.K., Trans. Faraday soc. 44, 226 (1948). ( 6 ) Holzrnan, E., and Suknarowski, S., IHD. ENG. CHEM.,A s . 4 ~ . ED. 7, 378 (1935). ( 7 ) Xlarron, T. E.. and Schifferli,
