INDUSTRIAL AND ENGINEERING CHEMISTRY
December, 1924
1275
spectrographsl3 indicate that the cellulose in plant fibers is composed of crystals symmetrically arranged with respect to the axis of the fiber, forming a parallelepiped. The group ( C ~ H I O Ois~regularly )~ repeated, indicating that cellulose is built up of anhydrocellobiose units. IrvineI4 in a recent pa.per has remarked that [‘speculation in the absence of experiment is best avoided in the carbohydrates.” The writer has hesitated for nearly two years to advance a formula for cellulose unsupported by laboratory proof. It seems, however, that the structure given below might clarify the question of the mode of polymerization, since it offers a tangible line of attack.
4-Hydrolysis a t (2) or (3) would result in a slight degradation of the molecule but not in the formation of an active carbonyl group; at both (2) and (3) a n aldehyde group would be formed, giving a hydrocellulose. The molecule would still be largely intact, but more readily hydrolyzable than normal cellulose. 5-Hydrolysis a t (2), (3), and (4)wouldrupture thecorresponding rings t o give a dextrin with reducing properties. It would be possible to obtain a dextrin without reducing properties by fission a t (3) and (4),or a t ( 5 ) and (6). The dextrins would be more or less readily hydrolyzed, since i t is improbable that there is much stability t o the facial 10 and 12-membered rings in themselves.
........................................................................................................................................
Toxicity of Nicotine as a n Insecticide and Parasiticide’
1!
CHzOH I 0-CH
SH20H
(3) O---CH
CH
I
I
(7) H + O J> ’H
I
CHOH
CHOH
J H o H o/FH
,...... j
C!H/(l)
o/--
i
CH.................>. i
CH/
CHOH
1 CHOH
{HOH
I
I
(6)
CHOH CH----O---C!H~(5) (4) dHzOH
o/C;H
By E. R. deOng (8)
CH
I
UNIVERSITY OF CALIFORNIA, BERKELEY, CALIF.
--- 0
CW20H
j
The foregoing formula represents in plane surface a polycyclic compound containing in horizontal section two 10-membered rings, and with two 10-membered and two 12-membered rings in the faces. The orthoglucosan groups are symmetrically arranged, forming a parallelepiped. So little is known of the higher membered cyclic compounds containing oxygen in the ring that it is useless to speculate on their stability. It would seem, however, that a polycylic compound as above would be far more stable than an 18-membered ring of the Irvine type from the standpoint of structure alone as well as crystal valencies. It will be noted that the butylene oxide ring common to the sugars is absent. The indirect evidence on which the assumption of the presence of this ring in cellulose is based does not affect the validity of the proposed formula. The salient features of the chemistry of the cellulose molecule as represented by the foregoing formula may be summarized as follows:
ICOTINE as a commercial insecticide is usually marketed as a nicotine sulfate, although the alkaloid itself is sometimes sold in the free or uncombined state (I-nicotine). Levorotatory nicotine is readily volatilized, and has been found to be much more toxic than when combined with acids to form nonvolatile salts. Hence, the commercial form of nicotine sulfate is much less toxic than when the alkaloid is freed from the combining acid. Nicotine sulfate is nonvolatile but becomes so in proportion as it is changed to the free base nicotine by the addition of alkali to neutralize the combining acid. Toxicity as an insecticide is due to a fumigating action (except where ingested by mouth), the curve of which is very similar to that from spraying. This is in accord with the work of McIndoo.2 A comparison was made of the rates of volatilization and the toxicity to aphids both by spraying and fumigating with free nicotine and nicotine sulfate. The volatilization rate from a film on leaf surfaces and from solutions was determineda by assays of the residual nicotine after exposure for definite periods. Bio-assays were made to determine the toxicity to aphids by spraying and by fumigation.
1-It is capable of giving only 2, 3, 6-trimethylglucose. 2-It is possible to obtain the theoretical yield of cellobiose octaacetate on acetolysis, but this is highly improbable, since: 3-It is also capable of yielding an isomeride of cellobiose, though it would not be maltose. Fission a t (l), ( 2 ) , (4), ( 5 ) ,and VOLATILIZATION TESTS (6) would give cellobiose, and at (7), ( 8 ) , (l), (3),and (4),the isomeride, isocellobiose. There are equal chances for the formaThe solutions used in all these tests (except No. 8) were of tion of crllobiose and isocellobiose. Failure to isolate the latter may be due to the greater ease of hydrolysis or acetolysis a t (l), nicotine sulfate which had been made from the pure alkaloid (2),. (6), and ( 5 ) due to the valency angles. Isolation of isocel- combined with sulfuric acid to neutrality with phenol red lobiose even in small quantity would be satisfactory proof of the and then by the addition of varying amounts of alkali changed CHzOH
I
CHOH
I
CHO
I I I I CH-0-CH I CHOH I
/CH
/ dHOH
CHOH
CHzOH “Isocellobiose”
existence of this linkage in cellulose. The celloisobiose of Ost,’6 according to Bertrand, is a mixture of cellobiose and procellose. Procellose is apparently a trisaccharide and has been assigned a chain formula obtainable by hydrolysis at one of the glucoside linkages in the Irvine formula. Herzog, CeZZuZosechemie, 2, 101 (1921); Umschau, 26, 53 (1921). 14 THIS JOURNAL, 15, 1163 (1923). 16 2. angew. Chem., 38, 100 (1920); Cellulosechemie, 8, 25 (1922). 16 Comfit. rend., 176, 1583 (1923); 177, 85 (1923).
18
in part to free base nicotine. Distilled water was used in all solutions except in two instances, where tap water was used alone and in another case where alkaline soap was added. The alkalinity of 100 cc. of the tap water used was equivalent to 1.3 cc. 0.02 N sulfuric acid. The difference in volatility between free nicotine and nicotine sulfate is very marked. The former after 24 hours shows only a trace of nicotine, while the latter has a range of recovery from 29.9 to 46.1 per cent, as shown in Table I. This proves that free nicotine may be entirely released in 24 hours and that from 85 to 90 per cent is available in the first 3 hours during clear weather, while from 13 to 19 per cent of the nicotine sulfate may be present after 48 hours of cloudy weather. Such long periods required for activation necessarily reduced 1 Abstract of a paper presented under the title “Comparison of Levoand Dextro-Rotatory Nicotine as an Insecticide and Parasiticide” before the Division of Agricultural and Food Chemistry at the 67th Meeting of the American Chemical Society, Washington, D. C., April 21 to 26,1924. 2 J . A g r . Research, 7, 89 (1916). a Chapin, Bur. Animal Industry, Bull. 133.
1276
INDUSTRIAL A N D ENGINEERING CHEMISTRY
VoL 16,No. 12
TABLE I-FOLIAGETESTSO F VOLATILITY OF NICOTINE
IN VARIOUS ALKALINE SOLUTIONS AND UNDER CONTRASTING METEOROLOGICAL CONDITIONS
No. 1 2 3 4 5 6 7 8 o
TYPEOF SOLUTION' N o alkali Acid '/a neutralized Acid neutralized In tad water In tab water plus soap equal to 4 pounds per 100 gallons Acid 8 / 4 neutralized Acid completely neutralized Free nicotine plus an amount of NaBOd equivalent t o that formed in No. 7 Nicotine sulfate was used in all tests except No. 8.
-CLEAR After 3 hours 48.5 50.0 42.7 51.5 36.6 27.9 10.4 14.1
-PER CENT NICOTINE RECOVERED AND RAINYWEATHER-CLOUDY After After After After After 24 hours 48 hours 3 hours 24 hours 48 hours 29.9 Trace 82.6 46.1 13.4 25.1 4.8 52.7 18.5 7.0 13.7 Trace 26.9 7.7 6.0 15.7 Trace 35.8 12.5 19.0 8.9 3.0 33.2 7.4 0 Trace Trace 15.5 Trace Trace Trace 0 17.9 0 Trace
0
0
41.9
2.7
Trace
NICOTINB DUSTS
the efficiency of a spray in two ways-the concentration of volatile nicotine may not be high enough a t any one time to become toxic, or rain may wash off the application before it is effective.
The use of dust carriers instead of water, as recently deveIoped, has certain advantages, but with it have come some complicated problems. I n the first phase, the diluent is a t present sold with the nicotine and at a high price; second, SPRAYING EXPERIMENTS the release of nicotine from dusts varies with the type used Nicotine solutions with varying alkalinity were used as in and to a certain extent with the amount of moisture present; the volatilization tests, but a t dilutions of one to one thou- third, the stability of the nicotine as found in nicotine sulsand. A close correlation is noted in Table I1 in the per- fate solutions is lost with the addition of alkali. Free nicocentage of mortality to the aphids between that solution made tine is so volatile and subject to chemical changes that it originally of free nicotine and the one in which the nicotine has thus far been impossible to store it for any length of time salt is changed to the free form by the addition of sufficient without loss. These difficulties can be largely overcome by alkali to neutralize the combining acid; the former showing a using nicotine sulfate in handling and storage, and combining mortality percentage of 76.5 and the latter, 74.6. The next it with alkali only as it is mixed into the dust used as a carto the lowest mortality (53.6 per cent) was noted where nico- rier and diluent. The data given in Table I11 show that the hydroxide comtine sulfate alone was used, thus proving that volatility is a primary factor in the toxicity of nicotine. Where tap water pound releases the nicotine more slowly than the carbonates. without additional alkali was used,the mortality was the low- Both calcium and sodium carbonate released nicotine more est (51.0 per cent) and where soap was added a t the rate of quickly than did hydrated lime both as nicotine sulfate and 4 pounds per 100 gallons, the mortality increased to 65.3 as free nicotine. The form of sodium carbonate used may per cent. Fumigation tests with the same solutions used in influence materially its action as a carrier. Its physical properties must also be considered in the selection of a suitable spraying gave similar results. type. Precipitated chalk was used in the experiments reTABLE 11-TOXICITY TO APHIDSa FROM SPRAYING AND FROM FUMIGATING ported in Table 111, but samples of crude soda ash and powWITH NICOTINE SULFATE IN SOLUTIONS O F VARYING ALKALINITY dered shell proved decidedly inferior. Dolomite when finely PERCENT OF APHIDSDEAD PH powdered has been found satisfactory. It will also be noted NATUREOP SOLUTIONb Spraying Fumigation No. value 53.64s. 1 1 6.5 1: 1000 distilled water that a slight excess of moisture (No. 7) in the dust materially 2 6.7 1: 1OOO'plus 2.4 cc. 1 N NaOH, in retarded the volatilization of the nicotine. Comparing an 49.7 55.5 distilled water 3 7.2 1: 1000 plus 4.8 cc. 1 N NaOH, in inert carrier such as kaolin with any of the alkalies, a close 60.9 58.9 distilled water 51.0 62.9 4 7.4 1: 1000 in tap water similarity will be noted to the action in solutions--I. e., that 5 7.6 1: 1000 in tap water plus soap at the nicotine sulfate is less volatile and consequently less toxic as 65.3 66.6 rate of 4 pounds per 100 gallons 6 7.8 1: 1000 plus 7.2 cc. 1 N NaOH, in an insecticide than is free nicotine. 65.4 88.4 distilled water 7
7.9
Free nicotine, 1:lOOO plus an amount of NaSOa equivalent t o that formed in N o . 6, in dis74.6 82.9 tilled water 1: 1000 plus 9.6 cc. 1 N NaOH, in 8 8.2 76.5 75.7 distilled water 7.7 22.3 Check Untreated aphids a Ivy aphid ( A p h i s hedevae Kalt.). Green peach aphid (RhopaZosiphum persicae Sulzer). b Nicotine sulfate was used in all tests except No. 7.
Commercial applications of the less toxic form of nicotine sulfate are usually made on the assumption, providing any thought is given to it a t all, that the water used as a carrier was sufficiently alkaline to free the nicotine from the combining acid. The addition of soap, ostensibly as a spreader, has a double value, for besides its film-forming value it increases the alkalinity' of the solution. In experimental work, however, it was found that tap water slightly above the average of hardness and requiring 1.3 cc. of 0.02 N sulfuric acid to neutralize 100 cc. did not give the Pullest toxicity possible even with the addition of soap. An increase in efficiency of from 20 to 40 per cent occurred in solutions where sufficient alkali was added over those that were neutral. Such results were secured in spraying and fumigating and in volatilizing experiments. 4
J . Econ. Entomol., 12, 75 (1919).
TABLE 111-VOLATILITYOF NICOTINE IN VARIOUS DUSTCARRIERS Propor-----CARRIER--tion of Proportion nicotine No. NICOTINE Substance Per cent Per cent 1.1 1 Free Hydrated lime 74.7 Sulfur 24.2 1.0 2 Free Hydrated lime 11.2 Sulfur 78.8 1.0 3 Free Sulfur 99.0 4 Free Hydrated lime 9 9 . 0 1.0 Free Sddium car5 bonate 99.0 1.0 Free Kaolin 99.0 6 1.0 Free Hydrated lime 94.95 1.0 7 Wntrr 4-05 .. _... Sulfate Kaolin 97.5 1.0 8 Sulfate Hydrated lime 97.5 1.0 9 Sulfate Sodium car10 bonate 97.5 1.0 Temperature range 58'to 70" F.
FORM OF
Time of exposure Hours 18
Nicotine recovered Per cent 22.3
18
Trace
18 18
None 45.7
18 18 18
None 96.8 54.6
18 18
100.0 25.1
18
None
NICOTINE AS A PARASITICIDE' The value of tobacco dust has long been recognized in the control of internal parasites of poultry. But ground tobacco, even when sacked, has shown a loss of 12 to 14 per cent of nicotine in one month. Such a loss coupled with the natural variation in the nicotine content emphasizes the need of standardized dosages. But again it is found that a combination of 5 This work was done in coijperation with S. B. Freeborn of the University of California.
December, 1924
INDUSTRIAL A N D ENGINEERING CHEilfIXTRY
nicotine sulfate with dusts always results in a loss of the nicotine content. Lloyd's reagent (an aluminium silicate) gave the best results, but even this showed a heavy loss on standing six months. Such powders should apparently be prepared not longer than a few weeks before consumption and if marketed should be dated and recalled after a definite period of time. Alkali is not a necessary part of poultry dusts, as the duodenum of the fowl near the cecum has an alkaline secretion, and it is a t this point that the roundworms are usually found. Suspensions of the prepared nicotine dusts in solutions of this pH value were found to release a large part of the nicotine.
1277,
TOXICITY OF NICOTINE TO CHICKENS Free nicotine was found to be very much more toxic to chickens when administered orally than was nicotine sulfate. One hundred milligrams of nicotine sulfate could be given with impunity in distilled water, but 10 to 65 mg. of free nicotine produced immediate death or collapse and death xithin a few minutes. A dosage of 3 mg. of free nicotine was found to be the minimum a t which death might or might not occur.
Trend of Developments in t h e Nitrogen Problem' By J. M.Braham FIXED NITROGEN RESEARCH LABORATORY, WASHINGTON. D. C .
T
HE problem of meeting the rapidly increasing demand for
annually, a quantity equivalent in nitrogen to about 3,300,000 tons of Chilean nitrate and nearly half of the world's inorganic nitrogen output. The part nitrogen fixation has played from 1913 to 1922 in meeting the world's nitrogen needs is shown in Fig. 1. It is seen that in 1922 Germany produced about 75 per cent of the total nitrogen fixed, and met the greater part of her nitrogen requirements in that manner. The fixation in this country, on the other hand, was very small. The situation a t present is essentially the same as in 1922. There are three processes now in operation on a large scale for the fixation of atmospheric nitrogen. These are commonly referred to as the arc, the cyanamide, and the direct synthetic ammonia processes. A fourth process is now in operation in this country on a small scale, producing sodium cyanide and hydrocyanic acid. Although ammonia can readily be produced from cyanide, it does not now appear likely that this process will be able to compete with the direct synthetic ammonia process in the manufacture of ammonia. ARC PROCESS-The arc process, in which nitrogen - becomes chemically combined with oxygen by passing air through an electric arc, was put into operation in Norway in 1905. It was the first air-fixation process to be commercially d e v e 1o p e d The present annual rate of fixation by this process is about 36,000 metric tons of nitrogen, and although there are arc plants in six different countries, over 95 per cent of the total is produced in the two plants in Norway. The main handicap of this process is its enormous power requirement, about 68,000 kilowatt-hours per metric ton of nitrogen fixed. Its commercially successful operation for fertilizer production is therefore limited to UNITED 9TATES countries having very cheap water power. There is a small arc plant in this country, located a t La Grande, Wash., but its 1913 1322 - consumption main product is sodium nitrite. - F i x e d atmospheric production No outstanding improvements in the arc process have been FIG. GELATION O F FIXEDATMOSPHERIC NITROGEN PRODUCTION made during the past ten years, TO TOTAL INORGANIC NITROGEN CONSUMPTION
nitrogen in combined form is now engaging the attention of all the important and progressive countries. The reason for this is that nitrogen is not only the heart of explosives, and hence of prime military importance, but it is also the key element in the fertilization of crops and consequently of utmost importance in meeting the fertilization of crops and consequently of utmost importance in meeting the food requirements of the world. A consideration of the principal sources of combined nitrogen suitable for both agricultural and military uses--namely, ammonia from coke and gas manufacture, Chilean nitrate, and the products of atmospheric nitrogen fixation-leads to the conclusion that the latter must be largely relied upon to meet the constantly growing demands. While this method of suppIying fixed nitrogen may not be the ultimate solution of the nitrogen problem, it will in all probability be the main contributor of fixed nitrogen for several decades. This general conclusion has been reached by workers in this field both in this country and abroad and as a consequence nitrogen fixation processes are now and have been for a number of years the subject of intensive investigation and development in many countries, particularly in Germany, France, Italy, England, Norway, Japan, and the United States. The outstanding developments in the nitrogen problem are in the nitrogen fixation processes and in the new materials which are being made available to agriculture by these processes. COMMERCIAL FIXATION OF NITROGEN Nitrogen fixation on a commercial scale was first accomplished less than twenty years ago, yet a t the present time air fixation processes produce nearly 500,000 metric tons of nitrogen 1
Presented before the Division
of Fertilizer Chemistry at the 68th Meeting of the American Chemical Society, Ithaca. N. Y., September 8 to 13, 1924.
0
4
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