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T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y . Vol.
pickling solution, and t h a t ferric thiocyanate is deep red in acid solution, but loses this color the minute t h e solution becomes alkaline. The following procedure is recommended for use of this indicator: To a IO-cc. sample of the pickle liquor a t a temperature of about 70' F. add several drops of a concentrated solution of either sodium or potassium thiocyanate. Without diluting, titrate t h e solution with standard alkali until the red color of the ferric thiocyanate entirely fades, leaving t h e solution a greenish yellow. I n connection with this titration, i t may be pointed out t h a t the coloration is more intense when t h e solution is used undiluted and t h a t if the color does not develop a t first, the addition of the alkali soon brings it out. The selection of t h e standard alkali depends upon whether the results of the titration are t o be expressed as percentage acidity b y weight, percentage acidity by volume, or pounds of anhydrous sulfuric acid per cubic foot of pickling solution. A standard normal solution of sodium hydroxide will be found convenient for expressing the percentage by volume or b y weight. I n this case each cc. of normal alkali represents approximately one per cent of free acid by volume. A 0.816 N solution of sodium hydroxide will be found convenient for expressing the results of the titration in pounds of sulfuric acid per cubic foot. Here the number of cc. of standard alkali used t o titrate I O cc. of pickling solution multiplied by 4 will represent the number of pounds of anhydrous sulfuric acid present in each cubic foot of the pickling solution. I n making the standard alkali solution i t must be borne in mind t h a t this indicator, though of constant accuracy, gives a n end-point slightly on the alkaline side and i t is therefore necessary t o use this indicator when making u p the standard solution. The addition of some iron salt like ferrous sulfate t o t h e acid solution which is used t o titrate against the alkali solution in standardizing t h e latter gives the necessary iron content t o the solution and is without influence on the titration. By this means a condition parallel t o the actual titration of the pickling solution is obtained. SOY-BEAN OIL
By Wilson H. Low C U D A R Y PhCKXNo COMPANY, OkfAHA,
NEBRASKA
Received December 18, 1919
A sample of filtered soy-bean oil was examined for total fatty acids, unsaponifiable matter, and glycerol, by calculation. Fifty grams of the oil were saponified by boiling for r. j hrs. under a reflux condenser with about 600 cc. of approximately 0 . 5 N alcoholic potash solution. U N S A P O N I F I A B L E MATTER-The SOlUtiOn Was transferred t o a separatory funnel, diluted with water t o a volume of 2400 cc., and extracted with 7 5 0 cc. of ethyl ether, followed by five more extractions of 2 5 0 cc. each. The ether residue (unfortunately not examined for free fatty acids) amounted t o 1.16 per cent, recorded as unsaponifiable matter. This is probably higher
12,
No. 6
t h a n would be found had a correction been made for free f a t t y acids with the residue. F A T T Y ACIDS-The solution, presumably free from unsaponifiable matter, was evaporated t o dryness in a large porcelain dish, treated with water, again evaporated to pastiness, and finally dissolved in water, and the fatty acids set free with dilute hydrochloric acid. The mixture was transferred t o a separatory funnel and washed free from mineral acid, as indicated b y methyl orange. The washings were combined and subsequently extracted with ether. The melted f a t t y acids were allowed t o stand warm in the separatory funnel and from time t o time t h e water which had collected upon rotating the funnel was drawn off, until finally very little was in evidence. The clear melted fatty acids were then drawn i n t o a filtering tube illustrated by the accompanying figure.
n:
A = Filtering tube, about one inch inside diameter, but any size is possible B = Shredded or rasped filter paper, well dried
C
-
Perf orated porcelain disc
D = Asbestos mat for filter
E = Another perforated porcelain disc F = Weighed crystallizing dish, protected from dust by a piece of cardboard
Shredded, or, better, rasped filter paper, if well dried, will absorb considerable moisture and be without action on the f a t t y acids. By maintaining t h e arrangement a t a low temperature, yet sufficiently high t o keep t h e contents well melted, the fatty acids percolated through into the dish. Filtration was allowed t o go on over night. The aqueous washings were extracted with more ether, the separatory funnel washed out with ether, and all the extracts combined and the f a t t y acids recovered. PATTY ........ACIDS .. Recovere; directly. Recovered ,, Recovered in ether extracts extracts, etc.. unsaponifiable matter). TOTAL (Free from unsapdnifiable Unsaponifiable matter. Unsa. TOTAL (Ordinary fatty acids) ,
GRAMS
...... ................... 39.7080 ............... 77.7752 .7752 ...... 47.4832 ........................... ................ . . . . . . . . . .
PER CENT
.... ....
94.966 1.160 96.126
I n weighing the fatty acids a constant slight gain was noted. This was probably due t o oxidation, as t h e dish and f a t t y acids had remained in t h e balance case a long time before weighing. If oxidation was the cause, i t must also have been going on during the time of filtering, and our result would be slightly high. GLYCEROL-Ten grams of the original oil (refined and practically free from free fatty acids) were saponified with standard alcoholic potash solution. The alkali consumed was equivalent t o 33.80 cc. of N solution, or ( 3 3 . 8 X 0.02r68 = 0.732784 g.) 7 . 3 3 per cent of glycerol anhydride or 10.37 per cent of glycerol. It may be said in passing t h a t this method of determining glycerol, if properly and carefully followed, is as accurate as any other known method. If there are any free f a t t y acids present in the oil they must be allowed for, using t h e true combining weight of the
June, 1920
T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
pure (free from unsaponifiable matter) fatty acids, which is given below, as t h e result both of calculation and experiment.
+
Impure fatty anhydrides unsaponifiable matter (100.00 7.33). = Calculated combining wt. of impure fatty anhydrides., Calculated combining wt. of impure fatty acids (274.17 f 9 . 0 1 ) . . ......................................... = 1.16).. = Pure fatty anhydrides (92.67 Calculated combining wt. of pure fatty anhydrides.. = Calculated mean combining wt. of pure fatty acids (270.73 9.01) =
-
-
.................................
+
............... ... ..................................
..
-
92.67 per cent 274.17 283.18 91.51 per cent 270.73 279.74
Five grams of the recovered pure fatty acids (39.708 g.) were saponified by boiling with excess of alcoholic potash and their combining weight determined. The actually determined mean combining weight found was 279.3, agreeing closely with the calculated value. IODINE ABSORPTIONWijis Method-The lower values in the case of the fatty acids shown below are due t o t h e fact t h a t they .did not contain the unsaponifiable matter, which itself would have absorbed iodine, and also probably t o some oxidation of the acid. Iodine number of original oil Iodine number of the pure f a
................
SUMMARY Total pure fatty acids in sample soy-bean oil Unsaponifiable matter (+ possibly some free
TOTAL ...............................
Glycerol. ............................ Combining weight of ordinary fatty acids Combining weight of pure fatty acids.. . .
138.45 and 137.39 132.83 94.966 per cent 96.126,per cent 283.18 per cent
THE PROXIMATE COMPOSITIONS OF KOREAN HEMP AND RAMIE By Yoshisuke Uyeda LABORATORY O F AGRICULTURAL CHEMISTRY, UNIVERSITY OF CALIPORNIA ADRICULTURAL EXPERIMENT STATION,BERXELEY,CAI,. Received December 31. 1919 INTRODUCTION
This paper is the first of a series of reports on Korean bast fibers from t h e standpoint of textile chemical research. Hemp and ramie have long been t h e most important raw textile materials in Korea. The former, grown throughout the country, is much larger in output than the latter and its bast fiber is obtained by an artificial retting process combined with scutching, and a spinning operation performable only by skilled hand labor. The latter, which is t h e chief textile fiber of China and known as China grass, is limited in locality and has a smaller output, but its quality is excellent and textiles made from i t are highly valued as summer cloth in Korea. The treatment of the ramie fiber is a kind of “dew retting,” a treatment commonly applied t o all bast fibers, followed by the same scutching and spinning operations as are used upon the hemp fiber. I n the course of experiments on bleaching the Korean hemp and ramie weaves which were made at t h e Central Experiment Station, General Government of Korea, by t h e present author, several difficulties were found. For example, t h e whiteness was not entirely satisfactory, t h e loss of weight after bleaching was considerable, and the strength of the weaves was much weakened by t h e treatment. I n order t o overcoine these troubles, i t is necessary t o have ample knowledge of the chemical composition of the fibers
573
and their behavior toward various reagents. Another important reason which led t o t h e present research is t h e fact t h a t the chemistry of the pectocelluloses, among which hemp and ramie are classified, is still obscure and offers many problems for investigation. The first step, therefore, is the consideration of the proximate composition of these fibers. Generally speaking, we have very little knowledge of the cheyical constitution or even the proximate composition of t h e I( compound’’ celluloses, not only pectocellulose, but also ligno- and adipocellulose. Methods of procedure for satisfactory analysis of compound celluloses are practically absent from the literature. Muller’ gave analytical results on hemp and ramie. He determined hygroscopic moisture, ash, water extract, fat and wax, and cellulose, estimated the residue by difference, and reported i t as “incrusting and intercellular substances and pectic constituents.” The present author2 also reported analytical results for t h e Korean products, following Muller’s .scheme. Cross and Bevan3 consider the question of “incrusting” morphological rather than chemical. As a starting point for further investigation i t is very desirable t o consider more accurate and complete proximate analytical methods. W. H. Dore4 of this Station recently proposed a scheme for the proximate analysis of wood and applied it to the proximate analysis of certain California woods. I t seemed possible t h a t this proposed scheme of analysis might be quite applicable t o the pectocellulose which was t h e subject of the present work. As f a r as our present knowledge extends, i t appears t h a t the structural substances common t o hemp and ramie consist chiefly of pectocellulose, together with lignin and substances extractable by organic solvents. According t o Cross and Bevan,6 pectocellulose is a substance which is decomposed by boiling with dilute alkali into insoluble cellulose and soluble non-cellulose derivatives (pectin, pectic acid, and metapectic acid). The material extracted by organic solvents consists chiefly of a fatty and waxy substance together with other substances of less frequent occurrence. T h e presence of lignin in both Korean hemp and ramie was noted by t h e author6 in the previous paper. The proximate compositions of the fiber are included in this paper, together with a discussion of t h e methods of analysis and the results obtained. EXPERIMENTAL
The samples which were used in this work were representative samples of Korean hemp and ramie of superior quality. ( I ) Hemp (Canlzabis sativa), retted and scutched. A single fiber has an average length of 1.2 to 1 . 3 meters and a breadth of 0.6 to 0 . 7 mm. I t has a pale brown color. ( 2 ) Ramie (Boeheria nivea), retted and scutched. A single fiber has an average length of 0 . 7 t o 1.1 meters Mathews, “Textile Fibers,” 1904, 191, 197. Chem. I n d . Japa-n, 21 (1918), 314; Chem. Abs., 1%(1918), 2127 J . Chem. Ind. J a p a n , 2 1 (1918), 1043; Chem. Abs., 13 . (1919), 794. a “Cellulose,” 2nd Ed., p 214. I 4 THIS JOURNAL, 11 (19159, 556. 5 “Cellulose,” 2nd E d , p 217. 0 L O C . cit. 1
* J.
