804
T H E JOURNAL OF INDUSTRIAL A N D ENGINEERING CHEMISTRY
limonene. Since Harries a n d Gottlob obtained 30 t o 50 per cent of isoprene from commercial limonene with t h e isoprene lamp, it seemed desirable t o s t u d y this volatile oil a n d compare its yield with t h a t from ordinary spirits of turpentine. I n preparing t h e 'material from t h e oleoresin t h e difficulties formerly met with in distillation by a current of superheated steam were easily overcome by heating t h e oleoresin a t a pressure of one millimeter, t h e volatile oil readily passing off without a n y tendency t o froth in t h e flask a n d with largely decreased opportunity for polymerization during distillation. Table I1 gives t h e results with t h e isoprene lamp. TABLE I1
Volume of re$due Time Temperin of ature P Per cent heating Crude Refined heating of of flask Hrs. oil bath Cc. Cc. isoprene Cc. Volume of distillate
Substance used
2.0 2.0 2.5 2.5
Totals... . . . . . . . .
-
175'
175'
185; 185
-
6.50 4.75 11.00 11.00
-
5.0 3.0 8.0 8.0
-
2.5 1.5 4.0 4.0
-
....
.... .... -
25.0
.... 33.25 24.0 12.0 25.0 No further condensate could be obtained b y continued heating of t h e residue. As was t o be expected t h e yield of isoprene from this volatile oil, rich in limonene, shows a largely increased yield, practically doubled, a s compared with ordinary spirits of t u r pentine. 9.0
PINE OIL
When resinous pine wood is finely divided a n d treated with s t e a m a crude oil distils off which on fractionation yields wood spirits of turpentine a n d pine oil. ,Teeplel has found t h a t pine oil consists chiefly of a-terpineol. T h e specimen used in this work showed a t 15' C. a specific gravity of 0.9403 a n d a n index of refraction of 1.4901. T h e results with t h e isoprene lamp are given in Table 111.
-
TABLE I11 Volume of Time Temperdistillate Volume of ature Per cent of Substance heating of Crude Refined of residue used Hrs. oil bath Cc. Cc. isoprene Cc. 2 2100 15 4 2.0 ... 200 CC. of pine o i l . . . . 2 210: 10 3 1.5 ... 2 210 7 1 0.5 125
Vol. 6, No.
IO
P l a n t I n d u s t r y ( N o . 235), reporting a n analysis of t h e oil of black sage, Ramona S t a c h y o i d e s , of Southern California. This analysis accounted for 62.5 per cent of t h e oil (camphor, 40 per c e n t ; cineol, 2 2 . j per cent), b u t t h e other constituents were not definitely identified. Since t h e black sage grows extensively in Southern California a n d might become of more or less commercial importance, it seemed t o us advisable t o continue this work, first with t h e idea of determining t h e yields of camphor a n d cineol a t a slightly different season of t h e y e a r ; secondly, t o definitely determine t h e other constituents, a n d whether or not a n y of t h e constituents were present in sufficient q u a n t i t y t o be commercially important. Through t h e kindness of Professor C. S. hlilliken, Assistant Superintendent of University Extension of Agriculiure, several hundred pounds of leaves a n d twigs which h a d been simply snipped from t h e ends of t h e branches, were forwarded t o us from t h e University Experiment Station a t Riverside, in February. These were several weeks in transit a n d probably suffered some loss from exposure b u t upon distillation with steam gave a yield of oil corresponding t o 0.90 per cent of t h e weight of material used. This yield is very much higher t h a n t h a t obtained b y t h e Bureau of P l a n t Indust r y , who made their distillation about t w o months later in t h e season, while t h e plant was in bloom, a n d obtained a yield of only 0 . 7 5 per cent. Not only was t h e yield much greater, b u t , a s might be expected, t h e physical constants of t h e oil were quite different from those obtained b y t h e Bureau of P l a n t I n d u s t r y , as may be seen from t h e following comparison: Bureau of Plant Industry 24O 0.9144 Soecific eravitv.. ........... 30.2 rotation 1.4682 Index of refraction.. Sol. in 70 per cent alcohol.. .. Sol. in 1112-t" 3112 vol. L Acid N o . . 2.5 Ester N o . . . . . . . . . . . . . . . . . . . Solid separated On cooling t o - Z O O C . .. . . . .
..
I
............ ........ .................. -
Our determination 15' 0.8979 24.4 I . 4729 Insoluble 2.2 1.6 No solid separated
I n order t o determine approximately t h e number of constituents in t h e oil a n d t h e relative quantities of each, we adopted a method which has been successfully used by L. F. Hawley in "Wood Turpentines" ( F o r e s t Service B u l l e t i n , N o . 105). This method consists in Totals . . . . . . . . . . . . . . . . 6 .... 32 a 4.0 125 fractionally distilling t h e oil with a Hempel column a n d REFINED SPRUCE PINE TURPENTINE plotting curves a s follows: ( a ) Temperature of distillation against t h e perThis substance, consisting chiefly of cymene, is collected as a by-product in blowing off t h e digesters centage weight which t h e fraction distilling a t t h a t in t h e manufacture of wood pulp from spruce pine. temperature bears t o t h e total. T h e specimen was furnished by t h e A. D. Little ( b ) Specific gravity against percentage weight. (c) Index of refraction against percentage weight. Laboratory of Boston. It showed a t I j' C. a specific gravity of 0.8639 a n d a n index of refraction of 1.4916; B u l l e t i n 105, Forest Service, gives approximately t h e 80 per cent distilled between 171.3' a n d 174.9' C . : zoo following interpretation of these curves. Suppose we are dealing with t w o volatile, miscible cc. of this substance were boiled three hours in t h e isoprene lamp b u t no crude distillate could be ob- components (A) a n d ( B ) , having boiling points T a n d TI, respectively. (A) a n d ( B ) are each present t o t h e served. UNIVERSITY OF NORTHCAROLINA extent of 50 per cent. If (A) had no effect on ( B ) t h e n CHAPELHILL ___.. all of (A) would distil over before a n y of ( B ) began t o come over, a n d plotting t h e percentage distillate INVESTIGATIONS ON OIL OF BLACK SAGE against boiling points t h e two vertical lines A X a n d BY BY CHARLESE. BURKEA N D CHARLESC. SCALIOKE would result. T h e break in t h e curve would indicate Received June 22, 1914 I n 1912 a bulletin was published b y t h e Bureau of a change of composition. I n an actual distillation this complete separation is never obtained, one component 1 J. A m . Chem. Soc., 30, 413.
3
-
_
.
-
Oct., 1914
T H E JOrRllrA L OF I N D C S T R I A L A N D ENGINEERING C H E M I S T R Y
affecting the boiling point of the other. The curve obtained when an ordinary mixture is distilled is represented by Curve I where there is a gradual gradation of the two components. A better separation is obtained by t h e use of a fractionating column and such separation would be represented b y Curve 11. I n general, approaching the vertical indicates a fairly constant composition, a change towards the horizontal indicates a rapid change of composition. Placing this interpretation upon it, Curve I1 would represent 45
Fraction I had a pinene-like odor, Fractions 2-7 had a cineol odor, a n d t h e rest of the fractions a camphoraceous odor. A small amount of solid matter began t o form in t h e condenser in Fraction 8 as t h e zooo mark was reached; this solid matter collected SO rapidly in Fraction 9 t h a t the condenser had t o be steam-jacketed t o carry on further distillation. The specific gravities were determined with a pycnometer, t h e index of refraction with a Pulfrich refractometer. From this d a t a the curves in Fig. I1 were plotted.
8
FIG I-CURVES
I L L L ~ S T R A T I N GTHE
T H E O R YO F DISTILLATION
FRACTIOSAL
per cent pure ( A ) , I O per cent rapidly changing. mixture, and the rest pure ( B ) . I n a like manner, the curves obtained from the specific gravity and index of refraction (two of the most constant properties of a n y oil) should be considered. A rapid change of the specific gravity or index of refraction indicates a rapid change of composition. T A B L EI-FRACTIONATION OF S A G EOIL S H O W I N G P H Y S I C ~PL R O P E R T I EOSF E A C HFn4cT1os TemperaSpecific Per cent Specific Index of tures distilled gravity Rotation refraction Fraction c. over 15O C. 15' C . 15' C. . . . 150--160 23.9 5.1 0.8i8 1.4616 . . . 160-170 23.2 1.9 0.892 1.4619 , ,, 170--175 22.3 18.6 0.896 1 ,4622 . . . 175-180 22.3 0.914 17.3 1 ,4626 . . . 180-183 20.5 0.926 6 8 1.4633 . . . 183-186 21.2 0.936 9.3 1.4643 ... 186-195 0,939 25.9 3 .3 1 ,4646 . . . 195-200 6. 1 0.930 (a) (a) 200 -205 18.6 0.940 . . Over 205 12.4 .. (a) Optical con3tants n o t taken, due t o formation of solid particles.
Table I shows the fractions we obtained from oil of black sage with the constants for each fraction.
805
.& d e &
&/an9 PrJ:.a78 ffl'cfiO??
.&8 A4676
*9/' /4626
--E?& k636 / a 4 5
FIG.IT-BOILING POINT,SPECIFICGRAVITY, INDEX OF REFRACTIOS CURVES FOR S A G EOIL
9 n examination of the curves in Fig. I1 shows a t least five components with possible traces of others. The first component is largely separated in Fractions I and 2 ; Fractions 3 t o 7 contain a t least two constituents and Fractions S and 9 two more. The sharp breaks between Fractions z and 3 and 7 and S, particularly noticeable in the specific gravity curves, indicate a sharp separation of t h e constituents a t these points. Fractions I and z were again redistilled, and with the exception of a small amount of resinous matter, practically all distilled a t the boiling point of pinene. This well-cooled. dry oil was saturated with hydrochloric acid and after some time almost completely solidified; after one recrystallization from alcohol the crystals melted a t 130' C. Pinene hydrochloride melts a t 131' C. The yield of pinene corresponded t o somewhat over 6 per cent of the whole material. Fractions 3 t o ;, after redistillation, were first tested
T H E J O U R N A L OF I N D C S T R I A L A N D E N G I N E E R I X G C H E M I S T R Y
806
Val. 6 , K O . I O
for cineol. To t h e well-cooled oil, glacial phosphoric acid was slowly added according t o Scammel's pr0cess.l After decanting as much of t h e oil as possible t h e magma was placed in a Buchner filter, t h e filter placed in a centrifuge cup a n d centrifuged; in this way we were able t o get t h e magma fairly dry without t h e loss of a n y of t h e adhering oil. After decomposition of t h e phosphate with hot water. a pure oil was obtained, C. The cineol t h u s obtained which melted a t -1' constituted 30 per cent of t h e whole. T h e cineol was also identified b y t h e formation of t h e iodol which, after recrystallization from benzene, melted a t I I I-
of Plant Industry gives a good indication as t o t h e variation of t h e constituents of t h e oil with t h e season. At t h e earlier season a t which we obtained our material, t h e oil contains a considerably higher percentage of t h e lower boiling constituents, while a t t h e later period a somewhat greater percentage of camphor was found.
II2O.
The use of Chinese wood oil as a varnish oil, although of fairly recent adoption, except in t h e Orient, has increased rapidly until a t t h e present time wood oil has come t o be considered t h e important oil of t h e varnish industry. The value of t h e oil has been said t o lie in its ability t o form actual combinations with the abietic acid of t h e rosin with which i t is cooked. This statement may be open t o question, b u t t h e fact remains t h a t varnishes of superior quality can be made from wood oil a n d rosin when they are properly manipulated. Most of t h e Chinese wood oil imported into t h e United States is gathered in small quantities throughout t h e rural districts of western China, a n d after passing through t h e hands of several native collectors a n d dealers, reaches Hankow, where i t is p u t into t h e export packages. The American buyer, although reasonably certain t h a t he receives t h e oil as packed a t Hankow, has no assurance t h a t t h e oil he buys is representative of t h e oil as pressed from t h e n u t . The wide variations t h a t t h e varnish-maker finds in t h e oil as he uses i t may be due t o variations in t h e n u t a n d in its t r e a t m e n t , or t o adulteration by one or more of t h e various middlemen during its openbasket travel from interior China t o t h e forwarder's warehouse a t Hankow.
The oil remaining in Fractions 3 t o 7 after t h e removal of t h e cineol constituted approximately 2 5 per c e n t of t h e whole. This p a r t of t h e oil was optically inactive a n d t h e boiling point a n d specific gravity indicated either terpinene or dipentene. An a t t e m p t was made t o form t h e dipentene tetrabromide, b u t although crystals separated t h e y were not in sufficient quantity t o be identified. On treatment of the oil with Beckm a n n ' s reagent* (30 p a r t s water, 6 parts potassium dichromate a n d j parts sulfuric acid), a heavy brown precipitate separated which showed t h a t a considerable portion of t h e oil consisted of terpinene. Fractions 8, 9 a n d I O were subjected t o a freezing mixture of ice a n d hydrochloric acid, a temperature -20' being attained. Solid crystals amounting t o z j per cent of t h e total oil separated. After t h e first sublimation these crystals showed slight optical act i v i t y , b u t after t h e second sublimation were optically inactive. They melted at 1 j 3 O C. Pure camphor melts a t I 7 j '. T h e semicarbazone prepared according t o t h e method of T i e m a n x ~ , melted ~ a t 232'. The semicarbazone of camphor melts a t 236-238'. Undoubtedly these crystals were camphor. After t h e removal of t h e camphor there remained approximately I O t o 1 2 per cent of t h e original oil. The boiling point was zoo' C . , specific gravity 0.917'. a n d specific T o a solution of t h e oil in rotation about 2j.9': petroleum ether, bromine was slowly added according t o t h e method of Wallach4 for preparing thujone tribromide; crystals were obtained which, after twice recrystallization from ethyl acetate, melted a t I 231 2 4 ~ . Thujone tribromide melts a t 1 2 2 ' . A small quantity of oily substance remained from Fractions 8, 9 a n d I O after t h e separation of t h e camphor a n d thujone; this was a resinous oil, probably p a r t l y formed b y polymerization during t h e process of distillation, a n d partly consisting of other high boiling terpenes which occurred in quantities too small t o be definitely determined. Pinene.. ...,. , , . , , , , , Cineol . . . . . . . . . , . . . . . Dipentene, terpinene. etc.. . . . . . . , . . , , , . , 4 Thujone . . . . . , . . . . . . . 5 Camphor.. . . . . . . , . . . 6 Resinous material., . . , 1
2 3
Analysis by Bureau Our of Plant Industry analysis 6 . 0 per cent ? 3 0 . 0 per cent 2 2 . 5 per cent ? Trace 4 0 . 0 per cent ?
2 5 . 0 per 8 0 per 25 .O per 5 . 0 per
cent cent cent cent
A comparison of our analysis with t h a t of t h e Bureau 1
2 3 6
U. S. Pharm.,'1900, p. 313 Baeyer. Ber., 27, 815. Tiemann, I b i d . . 28, 2191. A n n . . 275, 196; 286, 129.
CHEMICALLABORATORY UNIVERSITYOF CALIFORNIA BERKELEY
EXAMINATION OF CHINESE WOOD OIL' B y E. E. WARE A K D C. L. SCHUXANN
METHODS O F EXAYIh-ATIOX
S u m e r o u s methods have been proposed for t h e determination of t h e relative purity of wood-oil samples. Polymerization of t h e oil b y heating a t a definite temperature for a definite length of time, various modifications of which treatment have been proposed by Bacon, Worstall, Potsdarner, Browne, a n d others,2 is t h e method in most general use a t t h e present time. This method seems t o have given t h e most satisfaction, since t h e analytical constants of wood oil vary within rather wide limits, a n d this variation does not seem t o be accompanied b y a corresponding variation in t h e working qualities of t h e oil, as judged by its action in t h e 1-arnish kettle. However, many buyers prefer t o depend upon t h e analytical constants in passing judgment on wood oil, claiming t h a t t h e personal equation has too strong a n influence on t h e results obtained by t h e heat polymerization method. T h e iodine number a n d t h e re1 Presented a t the 17th Annual Meeting of t h e American Society f o r Testing Materials, rltlantic City, June 30 t o July 3 , 1914. 2 Boughton, "Testing of Chinese Wood Oil," Proceedings A m . Sac. Test. M a t s . , 13 (1913), 923.
