4 S D E-VGISEERI-VG C H E M I S T R Y Vniversity, Kingston. Ontario. n o x Metals Department, Deloro Mining & Reduction Company, Deloro, Ontario. The authors wish hereby t o acknowledge their indebtedness t o these gentlemen, and as well t o l f r . R . C. Wilcox, Research Laboratory. Queens UnLrersity, Kingston. Ont., now analyst, The Exolon Company Thorold. Ontario. b y whom most of t h e analyses reported in this paper m-ere made. 156
SIXTH
STREET, CAXBRIDGE,hZ.455ACHUSETTS
NOTES UPON OIL TESTING B y ACGUSTUSH. GILL Receired October 21, 1916
I-A
T E S r F O R OILS B Y S A L T I N G - O U T T H E I R SOAPS
I t is a well known fact t o t h e commercial soap maker t h a t different soap stocks require varying amounts of salt for t h e “salting out” process. I t occurred t o t h e writer t h a t if this could be made quantitative, i t would form a n additional criterion by which t o judge of t h e purity or genuineness of a n oil. Reference t o t h e literature revealed t h e fact t h a t this principle h a d already been made use of by Carpenter’ for detecting t h e presence of cocoanut and palm oils in soaps. Soap from ordinary oils requires from 8 t o I O cc. of a saturated solution of salt, whereas t h a t from cocoanut oil may require jo cc. The procedure is as follows: 2 g. of t h e oil are saponified with j cc. of I O per cent caustic soda, adding alcohol if necessary. Evaporate t o dryness on a water bath. dissolve t h e soap in warm water, cool, neutralize with hydrochloric acid. using phenolphthalein as a n indicator, a n d make up t o jo C C . Titrate I O cc. of this solution with salt solution ( 3 2 0 g. t o t h e liter) in a bottle after t h e manner of t h e determination of hardness in water until the lather obtained just does not persist for five minutes. From t h e HC1 used, and this titration with salt, calculate t h e grams of salt necessary t o precipitate t h e soap found from I g. of oil. The following results were obtained : T ~ B LI-GRAMS I~ NaCl P E RGRAMOIL Oil I I1 Pure olive . . . . . . . . . . . . . . . . . 2.2 2.1 11.6 Suspected sample Olive Foots(?), , , , , , , , . , . , , 1 0 . 6 Cottonseed.. . . . . . . . . . . . . . . 8.0 8.6 Linseed . . . . . . . . . . . . . . . . . . . 1 4 . 6 12.9 Oleomargarine.. . . . . . . . . . . . 2.8 2.8 Butter . . . . . . . . . . . . . . . . . . . 1.4 1.2 Cocoanut., . . . . . . . . . . . . . . . . S o end point obtainable.
T h a t something was really wrong with t h e olive foots 11-as evident from t h e fact t h a t in making soap from
t h e m in a large way, i t h a d t o be “broken” twice a n d t h a t nearly double t h e usual quantity of salt was required. 11-.4
TEST FOR GELATIKOUS MATTER I N L I S S E E D OILS
I n determining unsaponifiable matter in linseed oil, it was noticed t h a t a white, cotton-like-looking cloud formed between t h e soap solution and t h e supernatant layer of gasoline. It was further noticed t h a t t h e oils which showed t h e greatest amount of this cloud or sludge were slowest in drying a n d gave t h e roughest, 1 W. L a n t Carpenter, Allen’s “Commercial (1910), 436
Organic Analysis,”
2
Yol. 9. S o .
2
dullest and least elastic surfaces. particularly in patent leather finishes. The procedure is as follows: Saponify I O g of the oil with 2 0 cc. I O per cent caustic soda, by heating in a 6 in. porcelain dish over a low flame. .idd x a r m water when necessary and boil until saponification is complete. Make up t h e soap solution t o 2 2 5 cc. in a graduate with warm distilled mater. Warm water should be used t o prevent t h e hydrolysis of the soap. Pour out 2 5 cc. into a 6 in. test tube, seven-eighths t o one inch in diameter, add 8 cc. of 8 6 ” gasoline (from Pennsylvania crude) and shake thoroughly. Whirl in a centrifuge a t 1800 r. p. m. for 3 min. by t h e watch a n d observe t h e amount of sludge t h a t forms between t h e layers. Ordinary linseed oil gives a sludge nearly I O nim. in thickness or more, while a n artist’s oil which had been thoroughly washed with water and allowed t o stand a n d settle gaye less t h a n j mm. which is t h e smallest amount ever seen in a linseed oil. The first linseed oil, on applying t h e “breaking“ test, “broke” a t about 2 9 j 0 C., while t h e artist’s oil did not “break” below 300’ C. Attempts t o remove all t h e sludge by centrifuging repeatedly ( u p t o nine times in one instance) with fresh gasoline were unsuccessful. More sludge was found in t h e ninth t h a n in t h e first centrifuging. The first time, however, gives comparative results. Xttempts t o make t h e test quantitative b y collecting and weighing on a tared filter were also unsuccessful. I~ASSACHCSETTS INSTITUTE OF TECHXOLOGY, CAMBRIDGE
COLOR TESTS FOR OILS-PALM
OIL
. B y AUGUSTUSH. GILL Received October 21, 1916
The chemist uninitiated in this subject would infer t h a t color tests for different oils rest upon t h e same firm basis as those for copper, iron or chromiumparticularly after hearing testimony in certain legal cases. Palm oil is positiT7ely sworn t o - n o t something giving reactions like palm oil-and this. on t h e strength of a single reaction lasting less t h a n t e n seconds! Speaking from a n experience of over thirty years, and from extensive a n d careful reading, this is not t h e case-color tests are merely circumstantial evidence. If a color test be obtained, there is a p r o b a b i l i t y t h a t a certain oil is present, b u t no certairtty. Xor can any positive conclusions be drawn from any one test, save t h a t of isolating unsaponifiable oil; one must have t h e evidence of several different tests, each confirming t h e other. Nor can any other conclusion be possible. The oils are products of organic life, and this is dependent upon conditions of growth, in t h e case of a vegetable oil, as t o whether t h e season be wet or dry, warm or cold, t h e fruit be underripe, fully ripe or overripe; and in t h e case of a n animal oil, upon t h e feed. A hog fed on corn gives lard of a higher titer test and lower iodine value t h a n one fed on mast. Similarly, cows fed upon cotton or sesame cake give milk, the fat of which responds t o t h e same color tests as do
