Turps.
G um turpentine.
T h ere is, then, some confusion in the use of the word turpentine, b u t scientific and com m ercial usage agree in ap p lyin g the term only to the oleo
resin referred to, or to the product derived there
from.
bags and placed in iron tra y s, these tra y s being placed on racks in a closed room contain ing a charcoal burner. In this m anner th ey are driec}
F ig. 11.— V a t used for p recip ita tin g citra te o f lim e.
down to a m oisture con ten t of a few per cent.
The product is packed in hogsheads and shipped largely to the U n ited S ta te s and E ngland.
TURPENTINE AND ITS ADULTERANTS.
B y Ar t h u r E . Pa u l. R e ce iv e d S eptem b er 18. 1908.
In the turpentine forests of our southern states the custom is to c u t a cup-shaped opening or
“ b o x ” into the pine tree, ab o u t n " across, 3"
wide, and 5J" deep, h avin g a triangular, or “ V ” - shaped, upper surface. A s this upper surface—
com m only called “ ra b b it’s ear” — “ bleeds,” the juice, of about the consistency of glucose, runs into the “ b o x ” and is collected. A t th e end of a w eek the upper surface is c u t afresh (“ str e a k ” ), and such a new “ str e a k ” is c u t e v e ry w eek for a season of nine to eleven m onths. T h e gum so ob
In this paper, the word w ill be used in its com m ercial sense, i. e., it w ill refer to the distillate from crude turpentine.
T urpentine is used in the m anufacture of paints and varnishes. I ts value, according to tradition, is due to its prop erty of actin g as a carrier of o x y gen, thus aiding in the hardening of the oils and gum s used. T h e correctness or fa lla c y of the theory has not y e t been satisfacto rily established.
T urpentine consists v e ry largely of the hydro
carbon “ pinene,” and to a sm aller extent, of
“ cvm ene.” The form er is readily polym erized b y sulphuric acid, the latter not.
Specifications.— Because of the scarcity and com p ara tively high price of turpentine* and its liab ility to adulteration, th e im portance to the consumer, of assuring himself of the p u rity of the goods pur
chased, is apparent. M any large buyers, being aw are of th is fa ct, b u y ion specifications. These generally include a list of lim its of physical con
stants, supposedly peculiar to turpentine. The specific g ra v ity , flash point, beh avior on distilla
tion, polarization, color, residue on evaporation, and insolubility in sulphuric acid, are the m ost com mon lim itations. T h e specifications also gen
erally include a statem ent requiring the turpentine to be “ pure.”
O f these, all b u t the last-m entioned clause are superfluous— the o b je ct of the specification not being to secure a certain quality of goods, b u t m erely to exclude the possib ility of sophistication, and are v irtu a lly m ethods for establishing purity.
T h e “ total solids” may be an exception, as th ey v a ry som ew hat even in pure turpentine, and it may be w ell to specify lim its, as th ey may be indic
a tiv e of q u ality.
Wood Turpentines.— T h is designation is really a misnomer, since these products are not included in the definition given for turpentine. H ow ever, th ey are used in place of turpen tine; according to m ost consumers, th ey answer the purpose equ ally well, and are of sim ilar com position. M oreover, their use has becom e quite general, and th ey have been, and are, com m only designated as wood
“ turpentine.”
A gain, we m ust bear in mind th at, because of the destruction of turpentine forests b y m ethods of collection now in vogue, future dependence for turpentine supply w ill p rob ably rest w ith wood turpentine.
T hree m arkedly different varieties are a t pres
ent m anufactured:
" S lu m p ” turpentine is m ade b y d estru ctive ly distillin g stum ps or other p arts of dead resinous pine, or the so-called lig h t wood. T h e products are w ood alcohol, pyroligneous acid, tar, charcoal, and crude wood turpentine. T h is last, upon re
fining, yield s a product which, b u t for its pungent, em pvreum atic odor, is considered b y users a v e ry good su bstitu te for turpentine. I t contains considerable pinene, and n otab le q uantities of cym ene, more, indeed, th an does “ turp en tin e.”
Steamed wood turpentine is m ade b y distilling fa t chips w ith steam and refining the distillate.
T h e character of the p rod u ct depends upon the kind of chips used, and more p articu larly upon the care exercised in its m anufacture. Som e specim ens are in no w a y superior to the “ stu m p ” v a rie ty , w hile others are h ard ly distinguishable from true “ g u m ” turpentine, the odor being ve ry sim ilar, in fact, more pleasant, and less pungen t; and as to p h ys
ical constan ts and chem ical com position, th ey are p ractica lly identical therew ith.
T h e third v a rie ty is interesting rather than com m ercially im portant, the o u tp u t a t the present tim e being insignificant. I t m ay be called "W o o d P u lp Turpentine,” bein g a by-p rodu ct in the m anufacture of spruce or other wood pulp. T h a t from spruce is com posed alm ost en tirely of cym ene, which is an isom er of pinene. Its p h ysical con
stants are sim ilar to those of turpentine, b u t it- is on ly v e ry sligh tly affected b y concentrated su l
phuric acid. Its odor is strong and peculiar, b u t is really less pungent and less offensive than th a t of an y of the other varieties, even the real “ tu r
pen tin e.”
Since the on ly objection to wood turpentines, raised b y practical users, is the odor, and as their price is b u t v e ry little below th a t of turpentine, it follow s th a t as a com m ercial adu lteran t th ey w ould have to be used in large quantities, so large as to be easily recognized b y the odor. N otab le quan
tities will be freq u en tly indicated b y the greater per cent, of total solids, the greater distillate from sulphuric acid in the m ethod given below and the greater residue from direct steam distillation.
F raction atio n too w ill show a wider range of boil
in g points. M any specimens, especially of the
“ stu m p ” kind, g ive d istin ct tests for rosin spirits.
R osin S p ir its.— T h is includes the lighter fra c
tions obtained during the distillation of rosin, in the m anufacture of rosin oil. I t is com m only m entioned in treatises on paints and so forth, as one of the adu lterants of turpentine. W hile it
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 . 29
m ay be so em ployed, the w riter has failed to find any evidence thereof, either a n a ly tic a lly or com m ercially. F or its d etection the m ethod of P . I i.
Conradson1 is the m ost satisfacto ry, and nothing better can, a t present, be suggested.
Petroleum Products.— W h atever m ay be the rela
tive m erits of the variou s kinds of turpentine, and whether the virtu es ascribed to them are real or im aginary, the fa c t rem ains th a t th ey h ave certain distinct physical properties, and com m and certain m arket values, none of w hich are shared b y an y of the petroleum products. H ow ever, some of the la tte r have certain p h ysical properties in com mon w ith turpentine, so th a t th ey are freq u en tly em ployed b y unscrupulous dealers for the purpose of adulteration. T h e num ber of turpentine sub
stitutes now on the m arket, is legion. T h e y con
sist alm ost in v ariab ly either of petroleum products pure and sim ple, or m ixtures thereof w ith turpen
tine, wood turpentine, asphalt spirits, or sim ilar products. Petroleum products are usu ally chosen, having a range of boiling points w ith in th a t of turpentine.
A m ong the b est know n of these are:
“ T u rp alin ,” price ab o u t 20 cents per gallon.
“ T errab en tin e,” price ab o u t 20 cents per gallon.
“ Sunoco S p irits,” price ab o u t 15 cents per gallon.
“ Chicago T u rp en tin e,” price ab out 30 cents per gallon.
“ N orw ay T u rp en tin e,” price ab out 40 cents per gallon.
“ N u tu rp s,” price a b o u t 40 cents per gallon.
“ T urpteen S p irits,” price ab o u t 30 cents per gallon.
“ V arnish T u rp en tin e,” price ab o u t 40 cents per gallon.
• “ Erco S p irits,” price ab o u t 15 cents per gallon.
W hatever m ay be the relative d esirab ility of turpentine as com pared w ith petroleum products, the consumer should know w hich he is using. If he is satisfied w ith the properties of kerosene for his purpose, it w ill be econom y for him to b u y it as such, a t the m arket valu e thereof. I f he pre
fers to p a y the e x tra price for turpentine, he is en
titled to th a t article, and should, m anifestly, as
sure himself th a t he is g e ttin g the pure substance, and is not p ayin g turpentine prices for petroleum products.
A s to the use of the term “ turpen tin e,” as in the case of the “ Chicago T u rp en tin e,” or “ N or
w ay Turpentine,” this is a misnomer, these products not being turpentine in a n y sense of the word.
1 J- S °c. Chain. Ind.. 16, 519 (1397).
M ETH O D S O F D E T E R M IN A T IO N .
Because of the co m p aratively low value of petroleum products as com pared w ith pure tu r
pentines, and because of their entire differences in chem ical com position, as w ell as in physical properties, the determ ination of even triv ia l am ounts of these substances is the principal problem in the exam ination of turpentines. T h e q u a n tita tiv e de
term ination presents m an y difficulties, and chem ists experience considerable trouble in deciding w ith certain ty as to the presence or absence even of this form of adulteration.
A s an exam p le of h asty, incorrect, and alm ost am using m isinterpretation of a n a lytical results, the follow ing letter m ay be of interest. I t cam e from a large user of turpentine in regard to a sam ple of wood turpentine, reported pure b y us, and pronounced adulterated to • the e x ten t of 40 per cent, w ith petroleum oil, b y their chem ist:
“ W e w rote th a t w e w ould report more fu lly to you on the sam ple of wood turpentine. Our chem ist advises us as follow s:
“ ‘ A m sending y o u sam ples of the fractions separated in the distillation of the turpen tine sam ple in question. Y o u r atten tio n is called to the low distillation points and gravities of Nos. 1 and 2, and also their objectionable odor. T hese por
tions do n ot e x ist in igood turpentine. N um ber 3 and num ber 4 are too low in g ra v ity , due to the presence of lighter oils, boiling a t the same point as the turpentine. N os. 5, 6, and 7 should not com prise over 5 per cent, of the sam ple, w hereas in this sam ple th ey m ake up 42 p er cent. Y o u w ill notice the h eavy, greasy ch aracter of No. 7.
T h is certain ly w ould not be a desirable turpentine sa m p le .’ ”
“ In exp lan ation of the above w e w ould say th a t Nos. 1 and 2 distilled a t below 300° and com prised 7 per cent, of the sam ple. Nos. 3 and 4 distil a t 3020 to 340°, and the g ra v ity is 0.850 of the first and 0.852 of the second. Nos. 5, 6, and 7 have a g ra v ity betw een 0.852 and o .930. N o. 7, which com prises 5 per cent, of th e sam ple w e sent him, is a d ark red, vile-sm ellin g liq u o r... ”
T h e above statem en ts are tab ulated below for the sake of convenience:
F ra ction . N os. 1 and 2. N o. 3. N o. 4. N os. 5 and 6 . N o. 7.
P e r c e n t ... 7 37 5
R em a rk s stron g o d or d a rk ; vile odor
should n o t b e o v e r 5 % Sp. G r a v 0 .8 5 0 0 .8 5 2 0 .8 5 2 to 0.930 B oilin g p o in t, b elow 150° 150° to 170°
A com parison of these results w ith those given
30
in the table below w ill show th a t the chem ist is m aking the erroneous assum ption th a t the proper
ties of turpentine and w ood turpentine are iden
tical, and these incorrect prem ises m ust necessarily lead to entirely incorrect conclusions.
I T h e m ethods a t present em ployed for detecting and determ ining petroleum products in turpentin e a r e :
1. F raction ation w ith or w ith ou t subsequent exam ination of the fraction s b y p h ysical m ethods.
2. P olym erization w ith sulphuric acid and m eas
urem ent of the residual oil.
3. R epeated polym erization w ith sulphuric acid and determ ination of the refractive index of resid
ual oil.
4. Polym erization w ith nitric acid, and m eas
urem ent of the residual oil.
Fractionation.— In carrying o ut this process the same details of procedure should a lw ay s be em ployed, and the results com pared w ith those on the sam e v a rie ty of turpentin e of know n purity.
One v a rie ty of wood turpentine can n ot be com pared w ith another, nor either of them w ith pure gum turpentine.
F. W . R ichardson and J. Iv. B o w e n 1 recommend fractionation and determ ination of the refractive indices of the fractions; b u t an y m ethod based on p h ysical m easurem ents cann ot be relied on for q u a n tita tiv e w o rk because of the different p h ys
ical constants for different petroleum products. In the article referred to, the refractive in d ex of tu r
pentine is given as 1.4 70 to 1.4 7 3 , and of petro
leum products as 1 .4 1 to 1.4 6 , which brings the m inim um for the form er, and the m axim um for the la tte r en tirely too close together.
A series of distillation s of know n m ixtures, the boiling points of like fractions being noted, together w ith their readings in the butyro-refractom eter, gave the follow ing:
I t is interesting to note th a t in the case of “ k ero
sene ad u lte ran t,” w hich is a petroleum product, chosen com m ercially for the purpose of ad u ltera
tin g turpentine, and of “ elaine oil,” a high-grade com m ercial kerosene, an addition of 5 per cent, cannot be recognized sharply. “ E rco sp irits,”
w hich is a 'lig h te r fraction, is easily d etected quali
ta tiv e ly b y this m ethod. “ H e x a n e ,” a ve ry ligh t petroleum ether, is not used for adu ltera
tion, b u t an addition of 5 per cent, can be readily recognized as above.
A lto geth er this m ethod is not satisfactory.
T h e products m ost freq u en tly used m ay escape even q u a litative detection, and the lighter prod
ucts could be m uch more easily, and ju s t as surely, found b y a m ere flash p oint determ ination.
Polymerization with SulpJmric A c id .— T h e m ethod of shaking a m easured q u a n tity of the sam ple w ith concentrated sulphuric acid, and reading the residual oil after a given length of tim e, is used v e ry larg ely b y p ain t chem ists. T h e m ethod is dangerous, on accoun t of possible exp lo sions, the results a t b est v e ry little b etter than a guess, especially if th e adu lteran t is present in sm all q uantities only.
T h e m odification devised b y M cCandless2 is quite ingenious, and fa irly satisfacto ry in m any cases. H e treats a 100 cc. sam ple g rad u ally w ith 50 cc. of concentrated sulphuric acid, shaking and cooling; repeats the process u n til a bu tyro- refractom eter reading of 22 or less is reached, and then m easures the su rvivin g oil.
T h e m ethod has, however, several d raw b acks:
the operation m ust be carried on rep eatedly; the loss is considerable. A gain , a petroleum fra c
tion m igh t be used h avin g a refractom eter reading greater th an 22 and cause confusion, or escape de
tection , and a fraction h e a vy enough not to be carried over b y steam , certain ly w ould not be found.
W o o d Steam S tum p Pure 5 % ker 5 % 5 % 5 %
pulp. w ood . w ood. turp. osene. elaine. erco. hexane.
B .P .-R f. B .P .-R f. B .P .-R f. B .P .-R f. B .P .-R f. B .P .-R f. B .P .-R f. B .P .-R f.
S ta rt ... 150 56 124 60 153 58 153 56 152 5S 152 48 110 22
10 c c ... . 156 57 150 68 155 58 155 56 153 58 154 53 150 49
20 c c ... . 157 57 157 70 156 58 156 56 156 58 156 54 155 55
3 0 c c ... 157 57 161 70 156 5S 157 57 156 58 157 55 157 57
4 0 c c ... 171 87 157 57 163 70 156 59 157 57 158 58 158 57 157 57
5 0 c c ... 157 57 16S 70 156 59 157 57 158 58 158 57 157 57
60 c c ... , 172 S7 15S 57 171 70 157 59 158 57 158 58 158 57 158 58
70 c c ... 160 57 174 71 158 60 158 57 159 58 161 57 158 58
S O cc... 162 59 177 73 160 62 159 58 161 59 163 57 159 58
90 c c ... 167 60 1S3 79 162 65 162 59 165 59 167 58 160 60
R e s id u e .. . . . --- 99 --- SO --- 99 --- 86 . --- 84 --- 78 --- 83 --- 84
o f th e adulterant o f the adulteran t
S p. ST... .8625 .S660 .S670 .S680 .7770 .7552
R e f r a c t .. . . 95 58 77 65 8 25 0 low
S o lid s .. . . 0.6 1.2 3.5 1.0
> J . Soc. Chtm . Ind., 27, 613. 1 J . A n . Ch. Soc., 26, 981.
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 . 31
Polymerization with Film ing N itric A cid .— The method of B u rto n 1 can n ot be recomm ended, b e
ing v e ry dangerous, exceedingly try in g and tim e
consum ing and, a t best, n o t a t all accurate. H is details, w hen tried exp erim en tally, w ill be found to be quite im practicable for a lab o rato ry m ethod.
T h e m odification, or rather the com bination, of old m ethods, em ployed b y the w riter w ith en
tire success, is co m p aratively easy, is safe and rapid, includes all the possible fraction s of petro
leum products, and gives alm ost q u a n tita tiv e results, excep t in the case of v e ry lig h t naphtha, which, to the w rite r’s know ledge, is never em ployed for purposes of adulteration. E ve n in this case as m uch as 50 per cent, of the am ount present is read ily separated, and as little as 1 per cent, of added ordinary m ineral product m ay be determ ined w ith certain ty.
T h e appended tab le show s lab o rato ry results, obtained on variou s know n substances and m ix
tures :
5%
h e a v y
*
Pure 1 % 5 % m in
W o o d S tu m p turpcn - kero kero- 5 % 5 % eral pulp. turp. tine. sene. sene. hexane, elaine. oil.
Steam d istil. . . . trace 4 .5 0 .3 1 . 0 1 . 0 1 . 0 4 .5 9 .0
R efractom eter . high high high high high 78 80
H2S O * d i s t i l.... 70 17 8 .0 10 .0 1 4 .0 1 2 .0 10.0 7
R efractom eter . 100 90 77 60 48 63 50 90
HNOv t rca tm 't. n on e 0 .5 1 .5 4 .5 3 .0 5 .0 5 .0
R efractom eter . 33 9 0 .0 low 18
R efractom eter o f the adulterant 8 8 low 25 60
T h e m ethod in detail is as follow s: 100 cc. sam ple, in a suitable flask (500 cc. Jen a K je ld a h l answers nicely), is distilled in a current of liv e steam. T h e residue and d istillate are transferred to separatory funnels and the w ater tapped off.
The distillate is returned to the flask, treated w ith 500 cc. of concentrated sulphuric acid v e ry grad
ually, shaken, and carefu lly cooled (MeCand- less’s m ethod). 25 cc. w a ter are added and the m ixture distilled w ith steam , to a to ta l of 100 cc.
W ith pure turpen tines the am ount of oil is uni
form ly 8 cc., an excess indicating adulteration.
This oil is added to th e residue from the first di
rect steam distillation.
A volum e of fum ing n itric acid, equal to three times th a t of the com bined residues, is placed in a separatory funnel and thoroughly cooled in ice water. T h e com bined oils are now added, drop b y drop, shaking carefu lly and keep in g cold.
A fter all the oil has been added, allow to rest a few m om ents and draw off the acid lay er. W ash
1Am. Ch. J.. 12, 102.
the rem aining oil once w ith fum ing n itric acid, tw ice w ith o rd in ary strong nitric acid, and fin ally several tim es w ith w ater. M easure th e volum e.
T h e refractom eter readings m ay ad van tageo u sly be m ade on the various products obtained, b u t are b y no m eans essential.
W ith pure turpentine a residuum of about 0.5 per cen t, w ill be obtained, and allow ance for this m ust a lw ays be made.
In the case of w ood turpentine 110 such residuum is obtained, or a t m ost, a m ere trace, and 110 cor
rection is necessary.
In the ab o ve series of experim ents, then, the results, a fter m aking the correction, are:
A d ded , Found, per cen t. per cent.
K erosen e a d u lteran t... 1 . 0 1 . 0 K erosene a d u lteran t... 5 .0 4 .0
E laine o i l ... 5 .0 4 .5
Mineral oil, h e a v y ... 5 .0 4 .5
H e x a n e 5 .0 2 .5
show ing th a t w ith such petroleum products as are com m ercially em ployed, the m ethod yield s alm ost q u a n tita tiv e results, irrespective of the physical constan ts thereof, or of the turpen tine em ployed.
A s little as one per cen t, is found w ith o u t an y trouble. W ith exceed in gly lig h t products — w hich are n o t used, how ever— the results w ould be low.
La b o r a t o r yo f
Ma r i n e ra n d Ho s k i n s, .
Ch i c a g o.
THE DETERMINATION OF TOTAL, FIXED AND