ANALYTICAL CHEMISTRY
298
(2) Bickoff, E., and Williams, K. T., Oil and Soup, 23, 65 (1946). (3) Bucher, D., Fishtry Market LVews,7, 17 (1945).
Table 11. Purification of Crude Nordihydroguaiaretic h i d
1
Starting Quantity Crude NDGA Yield of Re- Melting Point M.P. 176-180” k., Crystallization crystallized Recrystallized G. Solvent NDGA, G. NDGA, C. 10.0 2 . 5 % phenol 2.7 184.5-186 5.0 0.97 n-amyl alcohol 1.8 185-186 10.0 1.04 fedistilled n-butyl al00 0 2.5 185-186 10.0 5 , 5 % n-propyl alcohol 1.8 184-186 125.0 Redistilled 9570 ethyl aloohol 67.6 183-185
Chemists’ SOC.,24, 403 (1947).
Cruess, W. V., and Armstrong, h l . , Fruit Products J., 26, 327, 344 (1947).
Duisberg, P. C., Shires, L. B., and Botkin, C. W., ANAL.CHEJI., 21, 1393 (1949).
Emmerie, A., and Engel, R., Rec. trav. chim., 57, 1351 (1938). Gisvold, O., J . Am. Pharm. Assoc. Sci. Ed., 37, 194 (1948). Gisvold, 0. (to Regents of University of Minnesota), Brit. Patent 618,406 (Feb. 22, 1949). Gisvold, 0. (to Regents of University of Minnesota), U. S. Patent 2,382,475 (Aug. 14, 1945).
guaiaretic acid tetraacetate, which indicated an apparent sample purity of 99.5%. This value undoubtedly is high, probably because of the presence, as impurities, of small amounts of other acetylatable chemicals, such as catechol, tannins, and flavanol or isoflavnnol pigments ( 1 7 ) . Waller (3‘7)observed that a 1%solution of bromine in chloroform reacted with nordihydroguaiaretic acid, with the evolutioii of hydrogen bromide gas and the formation of a brick-red bromination product. Attempts were made to adapt the U. 8. Pharmacopoeia phenol assay procedure ( 3 6 ) ,which employs the 0.1 N bromine or Koppeschaar’s solution, for quantitative determination. In this assay procedure (%?), an excess of bromine quantitatively converts the phenol to the 2,4,6-tribromophenol. However, the reaction between the nordihydroguaiaretic acid and the bromine is not stoichiometric. Working with samples of crude nordihydroguaiaretic acid, melting point 176-180’ C., spectrophotometric data were obtained using the Lundberg and Halvorson (21) modification of the Emrnerie and Engel (‘7) iron bipyridine method, which indicated an apparent sample purity of 92%. Although, as Lundherg and Halvorson ( 2 1 ) state, the reaction is almost completely lacking in specificity, the method described by these authors gives data which are a useful indication of the apparent purity of the sample in terms of nordihydroguaiaretic wid present. Saniples available in 1945 melted at 177-180” C. A spectrophotometric method has heen reported (6).
Ihid., 2,408,924 (Oct. 8 , 1946). Ibid., 2,421,117 (May 27, 1947). Ibid.. 2,421,118 (May 27, 1947). Ibid., 2,444,346 (June 29, 1948). Gisvold, 0.. Bope, F., and Rogers, C. H., J . Am. Phnrm. Assr~c. Sci. Ed., 37, 232 (1948). Higgins, J. W., and Black, H. C., Oil and Soup, 21,277 11944). Horn, G., and Gisvold, O., J . Am. Pharm. Assoc., 34, 82 (1945). Kesterson, J. W., and McDuff, 0. R., Am. Perfumer Essent. Oil Rea., 54, 285 (1949). Lauer, W.M. (to U.S. Secretary of Agriculture), U. S. Patent 2,373,192 (April 10, 1945). Lundberg, W.O., Dockstader, W. B., and Halvorson, H. O., J .
Am. Oil Chemists Soc.. 24, 89 (1947).
Lundberg, W. O., and Halvorson, H. O . , Proc. Inst. Fwo’ Technol.. 1945. 115.
Lundberg. W.O . , Halvorson, H. O., and Burr, G. O., Oil and Soap, 21, 33 (1944).
XIattil, II., and Luddy, F. E., Oil and Soup, 21,307 (1944). Riemenschneider, R. W., and Speck, R. M., Ibid., 22, 23 (1945). Silver, R. E., Food Inds.. 17, 1454 (1946). Smith, F. H., Brady, D. E., and Comstock, R. E., I n d . E n g , Chem., 37, 1206 (1945).
Stirton, 4 . J., Turer, J., and Kiemenschneider, R. W.,Oil
ACKNOWLEXMER-T
The friendly cooperation of the Casner Candelilla Co., A41pine arid Presidio, Tex., which constantly and promptly has supplied the rreosote hush material required for these investigations, merits appreciation. Through the courtesy of A. V. Caselli, Shell Chemical Co., and J. B. R. Caron, Shell Oil Corp., a supply of high quality cresylic acids was made available for this work. LITER4TURE CITED (1) Adams, J. (to Regents of University of Minnesota), U, S. Patent 2,421,109 (May 27, 1947).
U I L ~
Soap, 22,81 (1945). Stoloff. L. S., Puncochar, J. F., and Crowther, H. E., Food I n d s . .
PURIFICATION OF NORDIHYDROGUAIARETIC ACID
The crude nordihydroguaiaretic acid may he purified by simple rerr\-stallization from the following hot solvents or solvent nultures: redistilled 95% ethyl alcohol, n-butyl alcohol, nbutyl alcohol-water, glycerol-water, krt-butyl alcohol-water, phenol-water, n-amyl alcohol-water, n-propyl alcohol-water, and acetic acid-water. I n most cases, the hot solution w a , ~ filtered through cotton or paper before being cooled, with resulting separation of the purified nordihydroguaiaretic acid. The nordihydroguaiaretic acid, melting point 184-185’ C,, may be obtained also by forming the tetraacetatr from the crude material with acetyl chloride, separating the reaction byproducts, then purifying an alcoholic solution of the tetraacetate ester with activated carbon, and, finally, hydrolyzing the tetraacetate with 2% hydrochloric acid and ethyl alcohol. The method of hydrolysis is described by Waller (37). I n Table I1 are shown some of the results obtained in the purification of the crude riordihydroguaiaretic acid by recrystallization from various solvents.
Clausen, D., Lundberg, W. O., and Burr, G. 0.. J . Am. Oil
20, 1130 (1948).
Stull. J. W., Ice Cream Trade .I.. 46, S o . 1. 86 (1950). (36) Stull, J. W., Herreid, E. O., and Tracy, P. C.; J . b u i r u .
.
499 (1948).
31,
(36) United States Phannacpoeia XII, p. 358. (37) JTaller, C . IT., Ph.D. thesis, Universit>- of Minnesota, July 1942. (38) Kaller, C. W., and Gisvold, 0.. ,J. Am. Pharm. Assoc.. 34, 78 11945). RECEIWDApril 10, 1950. Presented before the Division of Biological L Chemistry at the 117th >Ieeting of the I \ Y E R I C A N C H E ~ I I C ASOCIETY. Houston. Tex.
Corrections In the article on “Estimation of Amino Acid? and .41nin(~on Paper Chromatograms” [ A x ~ LCHEM., . 22, 1327 (1950) 1 “niicromole*” should have been used in place of “millimoles” in wvrral instances. Page 1327, second column, third line under heading Plrparstion of Standard Solutions.” Page 1328, Figure 2. Page 1331, second rolumn, fifth line under Table 111. RICHARD ,J. ~ ~ I A I V K ”
In the article “Analytical Applications of Ion Exchange Srparations” [ANAL. CHEM., 22, 1368 (1950)] reference to a personal communication from Henry Freiser was inadvertently omitted in connection Tith the following statement: “The stoichiometric release of hydrogen ions by the organic cation exchangers suggests a simple rapid means of preparing standard acid.; and bases.” JACK SCHCBERT
