Apr
,
T H E J O C - R S A L OF I-Y-DL-STRIAL .4r\.D E.YGI.YEERI.YG
1913
used and the manganese determined by the bismuthate method. Table IT' shows the results. The percentage of manganese is figured on t h e oil. TABLEIV-MANGANESE CONTENT O F RAW LINSEEDOIL Ash Manganese .4sh Manganese Sample No. Per cent. Per cent. Sample No. Per cent. Per cent. 1... . . . . . 2........ 3... . . . . . 4..
...... 5 . ....... 6. . . . . . . . 7 . ....... 8 . . , , ,.
. .
0.16 0.02 0.03 0.16 0.03 0.18 0.18 0.16
0.0004 0.0005
Faint trace 0.0005
Faint trace 0.0003 0.0002 0.0003
9 . . . . . . . 0.19 10.. . . . . . 0.21 1 1 . . . . . . . 0.05 1 2 , . . . . . . O .03 13.. . . . . 0.03 14. . . . O .04 15. . . . . 0.16 0.16 16.. ,
0.0008 0.0006
Faint trace Faint trace 0.0005
Faint trace 0.0005 0 0003
CONTRACTS LABORATORS BUREAUO F CHEMISTRY WASHINGTON, D . C.
PINE NUT OIL BY MAXWELLADAMSAND AUGUSTHOLMES Received January 3, 1913
The nut pine tree, Pinus M o n o p h y l l a , also known as Pinus F r e m o n t i a n a , Pinon Pine and Grey Pine, according t o Helleri grows along the eastern slopes of the Sierra Nevada Mountains from Steamboat Springs on the hTortht o Lower California on the South. I t varies in height from a mere shrub, on the borders of t h e desert. t o a magnificent tree almost a hundred feet in height, in the Tehachapi Mountains. On the middle scale of t h e cones of this tree is borne an oblong thin-shelled seed about 15 mm. in length and weighing about one gram. The color of the nut is yellowish on the upper surface and dark reddish brown on the lower. The endocarp is resinous and oily, possessing a rich and pleasant taste. Capt. John C. Fremont.2 who first discovered this species of pine. in January. 1844, near the present site of Carson City, Nevada, states t h a t the nuts from this tree constituted the principal subsistence of several Indian tribes, whom he visited during his explorations in the Great Basin. At the present-time t h e Indians still gather the nuts in large quantities; a part is sold in the local markets, the remainder is used b y the Indians for food. The nuts used in t h e following experiments were gathered from trees growing on t h e mountains west of Walker Lake. Nevada, in the Autumn of 1911. A routine analysis of the nut kernels gave the following results: .4ir-dr4. Per cent. Water. . . . . . . . . . . . 7.88 Ash . . . . . . . . . . . . . . . . . . . . . . . 2 60 Ether e x t r a c t . . . . . . . . . . . . . . . . . . 2 2 . 7 7 Crude fiber.. . . . . . . . . . . . . . . . . 0.65 Crude protein. . . . . . . . . . . . . . . . . 8 . 9 4 Nitrogen-free extract. . . . . . . . . . . 5 7 . 2 1 Nitrogen. . . . . . . . . . . . . . . . . . . . . . . 1.43
Green Per cent. 61 S i 1.08 9.49 0 27 3 73 23.86 0.59
IVater-free Per cent. 2 82 24.70 0 70 9.70
62.08 1.55
About eight kilograms of the nuts were partially air dried, hulled, the kernels ground and the oil extracted with ether in a Jacobson extractor.3 The nuts used in one extraction gave the following yield: ............................. .............................. Weight of oil extracted.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Per cent. of oil in n u t s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Per cent. of oil in kernels.. . .... .... Muhlenbergia, 6 , 335. Fremont's First and Second Expeditions, p. 221. Jour. A m . Chem. Soc., 23, 2052.
522 grams 400 grams 65 grams 12.4
16.2
CHEMISTRY
285
The oil obtained from the evaporation of the ether extract is of the consistency of ordinary olive oil and a t first is light yellow in color, b u t upon standing in the laboratory the color gradually fades. A sample which remained near a window for a year became entirely colorless. The oil has a pleasing aromatic odor and agreeable taste. Blasdale' reports t h a t a sample. bought in the open market, and supposed t o be pine nut oil, examined by him, had a disagreeable odor and rancid taste. The oil in question must have been extracted from stale nut,s, or obtained from the nuts of some pine other than Pinus M o n o p h y l l a , for the physical constants. determined b y him, differ markedly from those obtained by us, when examining the freshly extracted oil. The oil melts a t -I j ', turns brown and decomposes without boiling a t 3 2 0 ° , but when heated under a pressure of 60 mm. it begins t o distill without decomposiThe saponification value. determined by tion at 305 '. the method of Kottstorfer, is 189.31, and the iodine absorption value, when determined by the method of Hubl. gives the following results: Expt. I 0 2466 Weight of oil used.. . . . . . . . 0 2663 Weight of iodine absorbed.. , , , , . Iodine value.. . . . . . . . . . . . 1 0 7 . 9 7
Expt. 11 0.2338 0,2525 108 00
The refractive index, determined with an Abbi. refractometer, is as follows: Temperature Degrees
Refractix-e index I ,4747 1 ,4533 1.4716 1 4698 1 ,4680 1 ,4662 1.4543
10 15 20 25 30 35 40
The refractive index, saponification value and iodine number of the oil, which had been bleached in t h e sunlight, was determined b u t no change mas noted, except t h a t the iodine number showed a slight diminution, which is probably due t o the absorption of oxygen b y the semidrying oils present. The oil was submitted t o fractional distillation, at a pressure of 60 m m , and each fraction examined with the refractometer. in order, if possible, t o separate i t into distinct chemical compounds, with the following results: 150 cc. of the oil were used for fractionating. Fraction 1 2
3 4 5 6
Temperature Degrees 305 305-15 3 15-20 320-50 350-65 365-70
Vol. of distillate
cc. 0.5
20 50 30 20 5
Ref. index a t 40' 1 ,4522 1.4531 1.4550 1.4562 1.4570 1 ,4594
At 3 2 0 ' the oil in the distilling flask turns brown and begins t o show signs of decomposition, which increases as t h e temperature rises. A t the end of the experiment there is in the flask a black tar-like residue. The first three fractions are liquids, the last three solids, at room temperature. The change in the refractive index and the variation in the melt-
' Jour. A m . Chem. Soc.,
17, 935.
T H E JOURLVAL OF I S D U S T R I A L AiYD E S G I S E E R I . V G CHE.\IISTRY
286
ing points indicate a difference in the composition of the several fractions, but when they were submitted to a second distillation they showed no tendency to produce substances with definite boiling points, and each decomposed somewhat when distilled and left a residue of tar. The glycerine in the oil was determined by oxidizing with potassium permanganate in alkaline solution, according to the method of Benedikt and Zsigmondy.' a n d found to be 9.2 per cent. When 2 0 0 grams of the oil, dissolved in alcohol, are saponified with potassium hydroxide, and evaporated to dryness, to free the residue from alcohol, it dissolves readily and completely in water, to a clear solution. This test indicates the absence of phytosterol. The mixed fatty acids when precipitated from the soap solution with dilute sulfuric acid, washed and dried, are light yellow in color, have a sp. gr. of 0.904 at I j ', and the yield is about 90 per cent. of the total oil. The mixed acids, when separated by treating their slightly alcoholic solution with lead acetate, according to the method of Gusserow-Varrentrap,z yielded 8 2 per cent. of unsaturated acids and 8 per cent. of saturated acids. This method does not give exact quantitative results as Lewkowitsch3 has already pointed out, and the following iodine value determination shows t h a t the saturated acids thus obtained are impure:
Vol. j, NO. 4
quantity available was not sufficient for a more complete identification. The unsaturated acids obtained are light yellow in color, have a sp. gr. a t 15' of 0.938 and have a refractive index as follows: Temperature Degrees I5 20 25 30 35 40 45
Refractive index 1.4657 1 ,4635 1 ,4623 1 ,4604 1.4588 1.4570 1.4550
The neutralization value of the mixed unsaturated fatty acids is 2 1 1 . 1 , and the mean molecular weight calculated from this d a t a is 265.7. Oleic acid, according to the investigations of Hazura,I is converted into hydroxystearic, a n d linolic acid into sativic acid, when the mixed acids. are oxidized with potassium permanganate in dilute alkaline solution. After oxidizing ten grams of the mixed acids by this method, the acids were recovered by passing into the solution a stream of sulfur dioxide, until the solution had a n acid reaction. The precipitated acids were then collected on a filter a n d separated by extracting the hydroxystearic acid in a Soxhlet apparatus with ether. The solution thus obtained was evaporated to a small volume and cooled, when the white laminated crystals of dihydroxystearic acid separated. The crystals thus obtained after a Expt. I Expt: I1 second recrystallization had a melting point of 132O. 0.4054 Weight of saturated acid used. . . . . 0.3844 The dihydroxystearic acid obtained was 44 per cent. Iodine number.. . . . . . . . . . . . , . . . . . 6.5 6 6 of the total unsaturated acids, which corresponds to Weight of unsaturated acid used.. . 0.4016 0.3782 Iodine number.. . . . , . , . . . . . . . . , . . 116.5 117.1 39.2 per cent. oleic acid. This method does not give 0.6031 gram of these mixed saturated acids was quantitative results, since a considerable amount dissolved by warming with I O O cc. of alcohol, sp. gr. of the dihydroxystearic acid remains in the ether 0.91, which had previously been saturated with pure solution, used for extraction and purification, but it stearic acid a t o o C., and allowed to stand in a flask serves t o fix the lower limit for the amount of oleic surrounded b y ice water for twenty-four hours. The acid present. white, laminated crystals which separated were filtered The residue remaining in the Soxhlet apparatus, from the solution and weighed when dry 0.0657 gram. which was insoluble in the ether, was extracted reTheir melting point was 66O. This yield shows the peatedly with hot water, and the sativic acid allowed presence of 10.8 per cent. stearic acid in the mixed to crystallize. The ten grams of mixed fatty acids saturated acids, or about I per cent. stearic acid in used gave 0.8 gram of a white crystalline substance the original oil. having a melting point of I 7 I O , which is slightly lower Using the iodine number of oleic acid as 90.07, than t h a t given for tetrahydrDxystearic acid. Were and the iodine number of the impure saturated acids, the acid pure this corresponds to 6.4 linolic acid. determined above, as 6.6 in the following equation Besides the oleic and linolic acids the presence of small I O O X 6.6 quantities of other unsaturated acids were indicated, . _ - per cent. oleic acid, we have but no confirmatory tests made were successful in 90.07 7.21 per cent. oleic acid present. Assuming t h a t the proving their identity. Assuming t h a t the mixed impure saturated acids obtained by the lead salt method fatty acids consisted entirely of oleic and linolic acids, consisted wholly of stearic, palmitic and oleic acids, calculated from the following formula, there mould be, calculated by difference, 82 per cent. .2: + y = I 0 0 palmitic acid present in the saturated acids. There was, however, obtained by the crystallization from alcohol of the magnesium salt of the mixed saturated where equals st he per cent. of oleic, 3' equals thepercent. acids, a very small yield of a n acid, which had a re- of linolic acid, and I I 7 . 0 j the iodipe number of the mixed fractive index of 1.4236 a t 7 2 '. This is identical with acids. there would be present io.j per cent. of oleic and t h a t given by Partheil and Ferrie4 for lauric acid. The 19.5 per cent. of linolic acid. But by the method of ~~
Jour. SOC.Chem. I n d . , 1886, 610. Liebtg's An%, 27, 153;56, 197. 3 Jour. SOC. Chem. I n d , 1890, 845 Archize. de7 Pharm.. 1903, 545.
Hazura we obtain only 6.4 per cent. of linolic acid. Experimental errors and inaccuracies of the two :*fond f . Chenaie, 1887, 147-260
methods do not satisfactorily account for so great Careful tests by the method of Hazura failed t o show the presence of linolenic acid. b u t from the high iodine absorption, some unidentified unsaturated acid appears t o be present. From these experiments we conclude t h a t the oil from the nuts of P i n u s JIonophylLa consists chiefly of the glyceride of oleic acid together with small amounts of the glycerides of stearic, palmitic. lauric and linolic acids.
a variation in results.
CHEMICALLABORATORS NEVADA RESO
1-NIVEKSITY O F
ANALYSES OF CERTAIN OF THE PACIFIC COAST KELPS’ By
E. G . PARKERA N D J . R . LINDEMUTH Received February 5. 1913
While many kinds of kelp are to be found on both the Atlantic and Pacific coasts, the giant kelps, peculiar t o t h e Pacific coast. are the most important t o the United States from a n economic standpoint because of their size a n d remarkable content of potassium salts. While the other varieties grow from two t o twelve feet in length, the giant kelps are found from 30 t o zoo feet in length, a n d in specific cases much longer. The composition of the Pacific kelps was studied first b y David M. Balch,a of Coronado Beach, California. He analyzed specimens of the giant kelps of the northern and southern Pacific coast of the United States, including .Vereocystis luetkeuna, Macrocystis p y r i f e r a , and Pelagophycus porra. Later in t h e course of an investigation of the fertilizer resources of the United States, under the direction of Dr. Frank I
