INDUSTRIAL A N D ENGINEERING CHEMISTRY
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tained, even with an excess of furfuramide, were fusible and soluble. After 2 mo. of intermittent heating, the resin was still fusible and soluble.
RESINSWITH ANILINE A few experiments were made on the basis of the work reported by Mains and Phillips. The results obtained by them, using aniline and furfural, and HC1 as the condensing agent, were repeated. We also prepared resins from aniline, using sodium carbonate. The resins were readily soluble in alcohol and acetone, giving a solution staining wood a reddish brown, very much the color of mahogany. The resin prepared by Mains and Phillips from furfuramide, by simply heating this compound at 100" C. for 1 hr., was prepared and studied. It was found that this resin was impure furfurin (C16H1203N2). Bertagnini in 18531° prepared furfurin by heating furfuramide at 110' to 120" C. for 1 hr., dissolving the resinous
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mass formed in alcohol, precipitating the furfurin as the double oxalate. This compound is soluble in boiling water and is decolorized by treatment with animal charcoal at the boiling temperature, filtered hot and allowed to crystallize from the filtrate. The furfurin is liberated by action of potassium hydroxide and obtained as a white crystalline compound which we have prepared in considerable quantities. The furfuramide resin prepared as outlined above was subjected to this treatment, and a very good yield of furfurin was obtained. BIBLIOGRAPHY 1-Stenhouse, A n n . , 35 (1840), 301. 2-Fownes, I b i d . , 54 (1845), 52. 3--Stenhouse, Proc. Roy. Soc., 18 (1870), 537. 4-Persoz, Wagner's Jahres-Berichts, 1860, 487. 5--Claisen, Ann., 237 (1887), 272. 6-Meunier, MaliBres grasses, 9 (19161, 4516. 7-Mains and Phillips, Chem. Met. Eng., 24 (1921). 661. 8-Novotny, U. S. P. 1,398,146 (November, 1921). 9-Beckmann and Dehn, Srtz. kgl. preuss. Akad. Wiss., 1918, 1201. 10-Bertagnini, Ann. chem. Pharm., 88 (1853), 128.
A New Test for Acrolein and Its Bearing on Rancidity in Fats' By Wilmer C. Powick Broc~EbfIcDIVISION,BURBAUOF ANIMAL INDUSTRY,WASHINGTON, D. C.
I
N T H E COURSE of a chemical study on the rancidity of fats, what is believed to be a new test for acrolein has been discovered. The test depends upon the formation of a colored condensation product between acrolein and phloroglucine in presence of hydrochloric acid and hydrogen peroxide. The test is best performed as follows: To 1 or 2 drops of dilute acrolein solution in a test tube 1 drop of a n approximately 3 per cent solution of hydrogen peroxide is added. After about 1 min., 5 cc. of concentrated hydrochloric acid (C. P., sp. gr. 1.19) are added, and the test tube shaken. Finally, 5 cc. of a 1 per cent ethereal solution of phloroglucine are added, and the whole shaken. A deep red color is immediately imparted to the hydrochloric acid phase, which, on spectroscopic examination, shows a well-defined, fairly narrow absorption band in the yellow-green region. I n the absence of hydrogen peroxide the red color is not obtained, while when an excess of acrolein is used the condensation product separates as a purple precipitate.
The essential feature in which this test differs from the Kreis test, so extensively employed as an index of rancidity in fats, is in the use of hydrogen peroxide and the spectroscopic examination. It is to be particularly noted, however, that the color yielded by rancid fats in the Kreis test is spectroscopically identical with that obtained with acrolein in the manner described, and that this color and spectrum are apparently distinctive of the condensation product which in the test described above is formed between phloroglucine and acrolein in the presence of hydrogen peroxide and hydrochloric acid. The saturated aldehydes, whose presence in r p c i d fats is generally recognized, do not respond to this test, either in the presence or absence of hydrogen peroxide. The next higher homolog of acrolein, crotonic aldehyde, gives a red color with phloroglucine-hydrochloric acid which rapidly disappears on standing, while in the presence of hydrogen peroxide no red coloration is obtained. While a number of other substances, such as vanillin, eugenol, cinnamic aldehyde, aged turpentine, and certain nonrancid cottonseed oils, give a red color in 1
Received September 28, 1922.
the absence of hydrogen peroxide, the spectra of these colors show general absorption throughout the green-blue-violet part of the spectrum, but no localized band as in the case of rancid fats and of acrolein in the presence of hydrogen peroxide. It would seem, therefore, that the same substance is responsible for the Kreis test in rancid fats as is formed by the action of hydrogen peroxide on acrolein, and that this substance is different from the reactive substance in certain nonrancid cottonseed oils. It is evident, therefore, that the Kreis test, when followed by a spectroscopic examination, may be used to distinguish rancidity in this product, although it was previously considered to be of doubtful value in this connection. Whether this substance, which gives the Kreis reaction in rancid fats and is formed by the interaction of acrolein and hydrogen peroxide, is a peroxide of acrolein; whether or not it is derived from oleic acid, as now seems to be the case; and whether it is formed naturally in rancid fats or artificially a t the time of making the test-possibly by interaction of oleic acid peroxide with pre-formed acrolein-are questions which are not yet fully answered. Studies on these points are nearing completion, however, and an early publication of the results is expected. As a result of laboratory tests made in the College of Industries of Carnegie Institute of Technology, Pittsburgh, Pa., under the direction of S. E. Dibble, head of the heating and ventilating department, it has finally been established that clay pipe for drainage and sewerage use is in every way the equal of the more expensive cast iron pipe which has been used heretofore. Not only have Professor Dibble's tests shown that (1) a proper bituminous compound can be used efficiently in jointing a pipe; ( 2 ) joints made in the manner developed will stand any pressure that the pipe itself is capable of standing, without any leak; (3) a pipe so jointed can be thrown out of alignment without causing a leakage a t the joints; and (4) leaks due to poor workmanship can be repaired easily and quickly; but he has gone further and has published actual chemical analyses of two of the bituminous compounds which he has found to be satisfactory.
