The Determination of the Hexabromide and Iodine Numbers of

Dana2 states that gypsum occurs intermingled with limestone. Clarke3 says, “Wollastonite is commonly found as a product of contact metamorphism, esp...
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Dec., 1918

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

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VI-The treatments decreased the soil acidity in t h e following order: Magnesite, dolomite, calcite, wollastonite, serpentine, rock phosphate, gypsum, and enstatite. VII-The results obtained in these experiments indicate t h a t t h e value of agricultural lime is in accordance with its acid-neutralizing power, rather t h a n with t h e CaO, MgO, or C o t contained, and t h a t t h e titration method is t h e most accurate a n d reliable method for determining t h e value of agricultural limes. S o a s AND CROPSDEPARTMENT PURDUEUNIVERSITY AGRICULTURE EXPERIMENT STATION

1: LAFAYETTE. INDIANA

F I G . 3--RELATIVE EFFECTOF DIFFERENT MINERALSAS S H O W N B Y AVERAGE INCREASE OF WHEATAND CLOVER AND DECREASE IN SOILACIDITY B Y THE HOPKINSAND JONES METHODS COMPARED WITH ACID-NEUTRALIZING POWER OF THE MINERALS DETERMINED B Y TITRATION. FULL CALCITEAPPLICATION TAKEN AS 100

It is a well-established fact t h a t certain silicates of calcium a n d magnesium compare favorably with calcium a n d magnesium carbonates in neutralizing acidity and in their beneficial action upon soils.’ Dana2 states t h a t gypsum occurs intermingled with limestone. Clarke3 says, “Wollastonite is commonly found as a product of contact metamorphism, especially in limestones;’’ also, “ I n many localities serpentine is associated with dolomite or dolomitic limestones.” Taking all these factors into consideration i t would appear t h a t t h e acid-neutralizing power of t h e limestone as determined by titration is t h e best method t o use for determining t h e value of agricultural limes a n d limestones. SUMMARY

I-The value of agricultural limes was determined by means of t h e acid-soluble calcium a n d magnesium, by means of COz determination with boiling hydrochloric acid, a n d b y digesting in standard acid and titrating the excess acid. 11-Pot cultures on two very acid soils were conducted using calcite, wollastonite, raw rock phosphate, gypsum, dolomite, magnesite, enstatite, and serpentine as correctors of soil acidity. 111-‘Wheat a n d clover were grown in each soil and t h e crop increases reported. JV-Soil acidity was determined after cropping b y means of t h e Hopkins potassium nitrate method and the C. 13. Jones calcium acetate method. V-Crop increases due t o various treatments were obtained in t h e following order, t h e highest being placed first: Calcite, dolomite, magnesite, wollastonite, rock phosphate, serpentine, enstatite, and gY Psum. 1 McIntire and Willis, THISJOURNAL, 6 (1914), 1005, Ames and Schollenberger, Ohio Expt. Sta., Bull. 306 (1916), 385; Cowles, Met. 6’ ~ C h e m .Eng., 17 (1917), 664. p Dana, “Manual of Geology,” 234. * Clarke, U. S. Geol. Surv., Bull. 616, 378 and 603.

THE DETERMINATION-OF THE HEXABROMIDE AND IODINE NUMBERS OF SALMON OIL AS A MEANS OF IDENTIFYING THE SPECIES OF CANNED SALMON By H. S. BAILEYAND J. M. JOHNSON Received June 21, 1918

A t the suggestion of M r . H. M. Loomis, formerly of the Bureau of Chemistry, an examination of salmon oils for their chemical and physical characteristics was made in 191j by L. B. Burnett in this laboratory. His preliminary experiments seemed t o indicate t h a t the iodine numbers and hexabromide values would furnish a method of distinguishing between the various salmon species. We have this year made a further study of oils expressed from canned salmon and believe t h a t the results we have obtained justify the assumption t h a t the oil from different species of salmon have characteristic iodine numbers and hexabromide values. I n order t o get a good working method for determining t h e so-callad hexabromide value of a n oil, we carried out a series of experiments using the different procedures suggested by previous investigators. METHODS OF A N A L Y S I S

The precipitation of insoluble hexabromides from t h e ether solution of oils and fatty acids was first accomplished in a qualitative way b y K. Hazura.1 A quantitative methodwforthe determination of t h e hexabromide value was afterwards worked out by Hehner and MitchelL2 This method depends upon t h e low solubility of the hexabromides in a solution of ether and glacial acetic acid. I n their method, the precipitate of hexabromides was brought upon a filter paper, washed with ether, dried and weighed. Procter and Bennett3 found difficulty with Hehner and Mitchell’s method especially with thz filtration of the precipitate. They changed t h e solvent and used carbon tetrachloride instead of ether, finally precipitating with alcohol. However, they did not succeed in getting good results when brominating the glycerides and recommended working with the fatty acids. L. M. Tolman4 modified Hehner a n d Mitchell’s method, using a centrifugz for separating and washing 1

Monatsh., 7 (1886), 637; 9 (1887), 148.

8

J . Sac. Chem. Ind., 26 (1906), 798. THISJOURNAL, 1 (1909), 340.

* The Analyst, 23 (1898), 310. 4

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the hexabromides, instead of carrying out these operations on a filter. He also weighed in t h e same flask in which precipitation took place. Tolman allowed the mixture t o stand only 30 min. after precipitation, but Sutcliffe,l as a result of his investigations, recommended t h a t after bromination, the mixture stand over night a t I I O before filtering a n d washing the precipitate. He found t h a t it was also necessary t o add enough bromine t o give a good red color instead of merely a yellowish brown as recommended by previous investigators. Sutcliff e's method was later called in question by GemmellJ2but he in reply3 demonstrated t h a t if his directions were carefully followed his method could be used with satisfaction. The procedure finklly adopted by us is a combination of the methods of Tolman and Sutcliffe, asfollows: About I g. of oil is weighed into a tared weighing tube I in. in diameter and 6 in. long, 2 5 cc. of absolute ether are added, and the mixture cooled in ice water. Xext there is added very slowly drop by drop from a small burette a mixture composed of 5 cc. of bromine and 2 5 cc. of glacial acetic acid. This reagent makes an excellent brominating agent and allows the bromine to be added more uniformly and gradually than when pure bromine is used. Besides, it gives the acetic acid necessary for a proper precipitation of the hexabromides. For most oils about z or 3 cc. of the solution are required to produce a deep red color, which is considered indicative of a proper excess of bromine. After the addition of bromine, the weighing tube is allowed to stand in a refrigerator, temperature under zoo C., over night. Next morning it is cooled in ice water and centrifuged from 2 to 4 min., the solvent is then decanted from the precipitate, I O CC. of ice-cold absolute ether added, the precipitate stirred up with the ether, cooled in ice water, again centrifuged 2 to 4 min. and the ether decanted off. This washing is repeated twice more and after decanting the final wash ether, the weighing tube is dried in an oven a t 100' C. t o constant weight, '/2 hr. usually being sufficient, In the case of salmon oils which gave a very large percentage of hexabromides, a weighed quantity of the oil was mixed with a weighed quantity of a cottonseed oil, which by test had shown no hexabromide precipitate, and the hexabromide value was then determined upon the mixed oil and calculated back to the original salmon oil. This was found necessary as a very bulky hexabromide precipitate could not be readily centrifuged and washed rapidly enough to prevent the solution warming up and dissolving some of the hexabromides. In order to get concordant results with an empirical method of this kind of course every precaution must be taken to work always under exactly the same conditions. After a little experience in the manipulation of this method, it is possible to obtain duplicate determinations which agree within 0.2 per cent with oils having a hexabromide value of 25 to 50. T h e iodine number was determined upon a separate portion of each sample by t h e regular official Hanus meth~d.~ ANALYSIS O F SALMON OILS

The salmon oils which we examined were obtained from canned salmon furnished us by Dr. E. D. Clark of the Food Research Laboratory and were collected by him from various typical districts on t h e Pacific Coast in 1916. Enough cans t o furnish t h e necessary 1

The Analyst, 89 (1914). 28.

Ibid,, 89 (1914). 297. 8 Ibid., 89 (19141, 388. 4 J . A . 0. A. C.,[3] 2, P a r t 11, 305. a

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amount of oil were opened, the cantents ground in a meat ?hopper a n d squeezed in a cloth bag in a small screw press. The oil and water mixture thus obtained was centrifuged, the water layer removed with a siphon, th4 oil dried with anhydrous sodium sulfate a n d filtered through paper. T h e determination of iodine n u m b e r and hexabromide value was made as quickly as possible after t h e sample had been prepared as a precaution against a n y oxidation which might take place upon standing. Table I gives the results obtained upon these samples. TABLE I 0. F. W.

No.

611 584 586 587 573 577 579 583 588 575 576 585 590 574 589 595 581

VARIETY SALMON Sockeye Alaska Red Alaska Red Chinook Chinook Chinook Chinook Chinook Chinook Silverside Silverside Medium Red Coho Chum Chum Chum Steelhead

SOURCE Puget Sound

So. Eastern Alaska

Central Alaska Bristol Bay, Alaska Columbia River Rogue River (fall) Columbia River Rogue River (spring) Washington Coast Rogue River Columbia River So. Eastern Alaska Washington Coast Columbia River Ceptral Alaska Bristol Bay, Alaska Columbia River

Iodine Number 141.55 140.72 148.10 126.62 128.03 134.48 129.13 130.40 129.06 166.30 161.05 166.40 155.61 133.10 136.19 133.25 141.90

Hexabromide Value Per cent 33.36 32.61 37.35 24.90 24.58 31.06 26.45 29.52 23.86 59.31 47.82 50.91 45.98 27.62 30.12 27.59 36.22

I n the following table are given the figures found for oils extracted with ether from single cans of Puget Sound salmon packed under direction of Mr. R. W. Hilts in 1912-13. TABLEI1

0. F.W.

No. 613 615 616

VARIETY SALXON Coho Pink Chum

Iodine Number 152.51 153.58 147.75

Hexabromide Value Per cent 43.07 40.17 35.33

T h e ether in these oils was removed by evaporation

on steam bath in a current of carbon dioxide. T h a t ether extracted oils do not differ apprzciably in their constants from cold pressed oils is shown by t h e analyses of t w o samples given in Table 111. TABLB I11 0. F.W.

No.

574 574 589 589

Chum

Chum

Chum Chum

VARIETY (cold pressed) ether extracted). , . . lcold pressed) (ether extracted), . . ,

... . . .. . . .. .. ,. ,. .. ... . . . . . . . . . . . . . . ..

Iodine Number 133.10 135.43 136.19 141.28

Hexabromide Value Per cent 27.62 27.91 30.12 30.23

T h e original scheme. €or this study of t h e salmon oils contemplated t h e analysis of fresh salmon as well as t h e canned product. Dr. Clark had individual fish of several different species extracted with ether during t h e 1916 season and these ether extracts were later sent t o Washington. Although t h e ether was only partially removed from t h e oils, a n d they were kept in wellstoppered bottles in t h e dark until they could be analyzed, there appears t o have been a marked change in their composition. I t is plainly evident t h a t the figures obtained upon these samples, as shown in Table I V , do not agree with those from the canned fish of t h e same species. TABLE IV

0.F. W. NO.

598 602 605 603 604

VARIETY King King Silver Chum Chum

Iodine Number 139.49 67.08 75.99 112.22 71.68

Hexabromide Value Per cent 26.83 i):44 2.36

...

Dec., 1918

T l l E J O U R N A L O F I i V D U S T R I A L A N D ENGI!VEERING C H E M I S T R Y

It might be assumed t h a t there was a change in t h e constants of t h e oil during t h e cooking incident t o t h e canning operations and t h a t t h e values for t h e oil from the fresh fish were the more nearly normal, if t h e latter were not much lower t h a n t h e corresponding values for the canned samples. An increase’ in the hexabromide and iodine values could hardly have been caused b y canning as so far as we know any alteration in fish oils due t o heat or oxidation always results in a decrease in these constants.

TABLEVI Chinook............................ Chum .............................. Red . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coho

..............................

Pink ............................... MediumRed .......................

c 0 PLTC L U SI 0 N s

Five species of salmon (Oncorhynchus)l are found in t h e waters of t h e north Pacific: ( I ) Oncorhyncus tschawytscha quinnat, tyee, chinook, spring or king salmon ; ( 2 ) Oncorhyncus f i e r k a , blueback, red, sukkegh, or sockeye salmon; (3) O m o r h y n c u s kisutch, s i l v x , coho, white or medium red salmon; (4) Oncorhyncus k e t a , dog, keta or chum salmon; ( 5 ) Oizcorlzymus g o r b u s c h a , humpback or pink salmon. With t h e m t h e fishermen also incorrectly class t h e steelhead trout, which really belongs t o t h e closely related genus Salnzo.

In Table I we have arranged t h e salmon oils according t o these classifications. It is readily seen b y rzference t o t h a t table t h a t t h e iodine numbers and hexabromide values run fairly close together for t h e same variety of salmon. 0. F. W. 587 was labeled Alaska Red. Our analysis, h o w e v s , indicated t h a t this was Chinook. After this sample was analyzed, we submitted additional cans of t h e same lot t o Drs. W. C. Kendall and IT. T. Bower, of ths Bureau of Fisheries, for identification. They, independently of each other a n d without knowledge of our results,, pronounced t h e sample as Chinook. Therefore, we have classified it accordingly. A digest of Tables I and I1 show t h e following variations:

....... . .....................

Red Sockeye or Blueback.. 140.72 Chidook Kink or Spring . . . . . . . . . . . 126.62 Medium’Red, kobo, or Silverside.. Humpback or Fink.. . . . . . . . . . . . . . . 133. IC Chum or Dog

Numbers Hexabromides Highest Lowest Highest 148.10 134.48

Hexabromide Value 23-3 1 28-30 33-37 43-46 40 48-59

This arrangement gives a much cleaner-cut distinction between t h e various species, b o t h with reference t o t h e iodine numbers and hexabromide values. The only case of over-lapping of t h e constants is between t h e chums and Chinooks.

DISCUSSION O F RESULTS

TABLEV Iodine Lowest

Iodine Number 127-134 133-136 141-148 153-156 154 161-166

IO01

32.61 23.86

37.35 31.06

T h e oils, therefore, show a little more characteristic difference in their hexabromide values t h a n in t h e iodine numbers. I n their iodine numbers, chums and reds overlap, and pinks and medium reds overlap, t h e highest value in t h e chums being nearly t h s same as t h a t in t h e reds. As only one sample of pink salmon was available for analysis, no sharp conclusion can be drawn as t o t h e limits of t h e values for t h e oil of this species. I t s iodine value would place i t with t h e medium reds, b u t its hexabromide value is lower t h a n t h e lowest found for any medium red sample.

If t h e coho oils are classified separately, and 0. F. W. 616, chum salmon, omitted, we have t h e following limiss in these particular samples. 1 John N. Cobb, “Pacific Salmon Fisheries,” Bureau of Fisheries, U. S. Department of Commerce, 1917, Document No. 839.

I-A new method or perhaps more properly a modification and combination of several methods f O T t h e determination of t h e so-called hexabromide valuz of fish oils has been worked out, using an acetic acid solution of bromine as the precipitating reagent. 2-Oils expressed from canned salmon, and dried b y t h e addition t o t h e m of anhydrous sodium sulfate, after t h e major portion of t h e water has been mechanically removed, have practically t h e same iodine and hexabromide value as the oils extracted with ether, provided proper precautions are taken t o prevent oxidation in the extraction. 3-In so far as a definite conclusion can be drawn from the analysis of comparatively few samples, t h e results obtained seem t o indicate t h a t it may be possible t o distinguish the variety of canned salmon by a determination of -the h-xabromide and iodine values of the oil. OIL, FATAND WAX LABORATORY BUREAU O F CHENISTRY u.s. DEPARTMENT O F AGRICULTURE WASHINGTON, D . C.

COMPOSITION OF THE WATERS OF THE INTERMOUNTAIN REGION B y J.

E. G R E A V ~AND S C. T. HIRST Received April 1, 1918

During t h e years 1916 and 1917 t h e chemical department of the Utah Agricultural Experiment Station made several hundred analyses of waters representing 58 streams, t h e majority of which were extensively used for irrigation purposes. The results obtained are of exceptional interest, for t h e y indicate t h e great quantitative and qualitative difference in t h e composition of t h e irrigation waters. Moreover, they clearly portray t h e enormous quantities of soluble salts which a t times may be carried t o soil b y water and t h e great p a r t which waters play in t h e formation of alkali soil. From t h e majority of streams monthly samples were taken during t h e irrigatlon seasons. These were collected according t o sbandard methods in carefully cleaned containers and shipped t o t h e laboratory where t h e analyses were made as soon as possible and according t o t h e following methods. METHODS OF ANALYSIS

SoLIDS-Fifty cc. of water were evaporated t o dryness on an electric hot plate in I O O CC. beakers, cooled in desiccators, and weighed accurately t o t h e fourth decimal place. C A R B O N DIOXIDE-Fifty cc. of water were titrated TOTAL