587
V O L U M E 21, NO. 5, M A Y 1 9 4 9 Table 11. Recovery of Dextrose and Levulose from 0.2qc Solutions and of Sucrose from 0.1% Solution (After treatment of 100 ml. of sugar solution with varied amounts of decolorizing carbon) car- B. & A. Code 1.551 Carbon Animal Charcoal, 325-Mesh bon, Dextrose. Levulose, Sucrose, Dextrose, Levulose Sucrose. r-/r hlg. % 7c % % % 100 99.6 98.5 98.3 100.8 99.0 100.8 200 99.6 99.3 96.0 100.1 100.0 100.8 300 99.6 98.5 92.8 98.2 100.0 100.0 500 98.8 98.4 88.8 100.0 99.0 100.3 700 98.4 97.3 84.4 100.8 98.0 99.6 1000 96.4 97.3 77.6 100.4 98.4 98,4
Table I l l . Recovery of Dextrose, Le\-ulose, and .Suerow from Solutions of Varied Sugar Concentration (After treatment of 100 nil. of sugar solution x\-ith 500 nip. of decnlorizinE carbon) B. & A . Code 1551 Carbon ..\nirnal Charcoal, 323-Xlesh Sugar., Dextrose, Leviilose, Sucrose. Dextrose, Levulose. Sucrose,
53
7c
5%
$4
%
5%
C‘
0.05 0.10 0.20 0.30 0.50 1.00
98.4
9G.O
100.0
99.6
98.8
98.9
80.0 88.0 92.4 93.2 95.6 97.2
98.8
100:!4
l00:O 99.6
68:l 98.6
96.0 98.4 98.4 99.2 98.4 48 8
,..
98.8 98.8
...
98.2 99.5
...
selected,for the decolorization of plant extracts for sugar analysis. Sugar concentration and the quantity of carbon must also be taken into consideration. As solutions of dextrose and levulose can be treated with selected carbons without appreciable loss, it is advisable to carry out hydrolysis after lead clarification but prior t o treatment Tyith carbon and thereby avoid the adsorption of sucrose. SUMMARY
The percentages of recovery of dextrose, levulose, and sucrose from ivater solutions after treatment Kith commercially available decolorizing carbons have been determined. Animal charcoals did not adsorb any measurable quantity of the three sugars, except sucrose a t the lowest &gar concentration studied. Sucrose recovery from the other carbons varied from 43 tu 87%. Within certain useful limits of carbon and sugar concentrations, ten of the tqelve carbons studied did not absorb levulose or de\trose. Sugar solutions were also treated with neutral lead acetate and dibasic sodium phosphate prior to the carbon treatment, and it was found that the adsorption of the sugars by the carbons was the same as from the water solutions. LITERATURE CITED
(1) Deitz, 1’. R., “Biblioglaphy of Solid Adsorbents,” p. lxxi, U. 5.
able quantity of dextrose. Only a t the lowest sugar concentration was there evidence of levulose adsorption by B. & A. Code 1551 carbon. The adsorption of sucrose by this carbon was appreciable a t all concentrations. Animal charcoal, 325-mesh, adsorbed 110sucrose except a t the lowest sugar concentration studied. The data show that i t is necessary to determine the adsorption of sucrose as well as dextrose and levulose when a carbon is
Cane Sugar Refiners and Bone Char Mfrs. and National Bureau of Standards, Washington, D. C., 1944. (2) Forsee, W.T.,Jr., IND. EXGCHEM., ANAL.ED.,10, 411 (1938). (3) Hassid, W. Z., Ibid., 8, 138 (1936). (4) Ibid., 9,228 (1937).
( 5 ) Hiscox, D. J., Can. Chem. Process Ind., 26,496 (1942). (6) Lott, R. V., Proc. Am. SOC.Hort. Sci., 46, 149 (1945). (7) Morris, V. H., and Wesp, E. F., Plant Phusiol., 7, 47 (1932).
RECEIVED Jul) 20, 1948.
STUDIES ON RESINS Specijic Color Reaction f o r Dehydroabietic Acid and Its Application i n Analysis of Technical Resins WlLHELJI SANDERJIANN Z e n t r a l i n s t i t u t f u r Forst-und Holzwirtrchaft, H a m b u r g - R e i n b e k , G e r m a n y ( B r i t i s h Z o n e )
This paper describes a new specific intensive blue-violet color reaction which has been used to detect dehydroabietic acid in various resin products. A resin containing dehydroabietic acid is sulfonated in the cold, and after standing 12 hours at room temperature is neutralized with concentrated sodium hydroxide or potassium hydroxide. A blue-violet color appears; the intensity varies with the amount of dehydroabietic acid in the sample.
T
HE simplest test for resinic acids is the color reactiou with acetic anhydride and sulfuric acid according to Storch and
Morawski ( 1 , 3 ) . However, this reaction is not specific because other compounds such as terpenoids give the same color. The Halphen-Grimaldi reaction with phenol and bromine ( 4 )is knoiyn to have the same disadvantages. Both of t,heseidentification tests show good results with I-pimaric acid, abietic acid, and proabietic acid, but not with hydrogenated resinic acids, dehydroabietic acid, d-pimaric acid, and the compound of I-pimaric acid with maleic anhydride. 4 new specific color reaction for dehydroabietic acid has bren found. PROCEDURE
In an ice-cooled test tube 0.05 to 0.1 gram of fine powdered resin is added in small portions to 2 ml. of sulfuric acid (density
1.84). After standing for about 12 hours a t room temperature the test tube is placed in a test tube clamp, and 3 ml. of water are added. Then slowly with a pipet a 50% solution of sodium hydroxide in water is added until the mixture shows an alkaline reaction. The reaction is extremely violent and every precaution must be taken. If the sample contains dehydroabietic acid a blueviolet color appears, which is stable for days and often for weeks. If the sample is acidified the color disappears but will reappear to a lesser degree if sodium hydroxide is added. If ammonia or amines are substituted for alkali hydroxide no color is produced, nor does any color appear if the neutralization with sodium hydroxide takes place in the cold.
.Spparently a sulfonic acid is transformed into a phenolic compound under the influence of heat and concentrated alkali hydroxide. If the pure sulfonic acid I1 is neutralized with concentrated sodium hydroxide there is no color reaction, but a very intensive one if I1 is first treated with sulfuric acid in the same
ANALYTICAL CHEMISTRY
588
But the resinic acids of the type of l-pimaric acid change their structure with the temperature, as shown in VI1 to XI. According to this scheme a rosin obtained from gum by distillation up to 180" to 200" C., should not give a positive reaction in the new test, as it contains no dehydroabietic acid. Indeed Table I1 shows that such rosins contain none or only traces of dehydroabietic acid. But in agreement with the scheme all resinic acids that have been heated to over 240' C.-e.g., resinic acids from distilled tall oil-give a dark blue-violet color. Not only the common RTood rosins but also the hydrogenated product Staybelite and the polymerized rosin P o l y p a l e contain considerable amounts of dehydroabietic acid. I t was OH found by diene titration ( 8 ) v VI that a wood rosin obtained by low temperature extraction of stumps contained a large amount of pyroabietic acids which did not react with maleic anhydride. Probably the dehydroabietic acid of such rosins obtained by extraction- has been formed by autoxidation according to the following scheme:
way as described for dehydroabietic acid. Therefore it may be supposed that the color is caused by a polyphenolic compounde.g., V-which has been formed from a polysulfonic acid like IV. The polyphenol V may be transformed into an oxyquinone VI which forms blue-violet sodium salts, analogous to quinones with hydroxyl groups.
H3C
COOH I
SOIH
OH I11
I1
OH
Iv
Table I shows that this color reaction is really specific for dehydroabietic acid. As many technical resins are characterized by the presence of dehydroabietic acid, this new color reaction is very useful in the analysis of technical resins. Technical resins contain several resinic acid isomerides. The varieties and amounts of these isomerides depend on the heat treatment they have undergone. The amount of d-pimaric acid ( X I I ) is nearly constant up to temperatures of about 230" C.
H3C
COOH
H3C
COOH
H,C
1
0-c
\ \
I
\ \
-H20
'.",: I
*d
