INDUSTRIAL AND EL1;GIXEERINGCHEMISTRY
September, 1928
tionary metal strips. The milk was always in contact with air through breathing tubes. At the end of the 30-minute period the copper strips were removed and placed a t once in running cold water and then successively rinsed in alcohol and ether, dried, and weighed. The loss in weight was taken as the measure of the rate of corrosion. The milk from each tube was ashed and the copper content determined by the xanthate method mentioned above. Copper contamination was guarded against by avoiding copper in equipment and reagents. The water used was redistilled in glass containers. In all cases control determinations were included in each set. Results
8
similar observation has been reported by Frazer, Ackerman, and Sands9 in connection with the solubility of monel metal in aerated 5 per cent sulfuric acid solution. The former observed a maximum a t 80' C. while the latter reported 70' C. The data are not in agreement with the'observations of Rice and Miscall,5 who reported that the solubility of copper a t the boiling point of milk was less than a t room temperature. It should be borne in mind, however, that these investigators exposed the metal for a long continuous period and therefore the change in composition of milk a t the higher temperature undoubtedly became a decided influencing factor, Table I-Loss
The data given in Table I represent the average of a large number of determinations of the loss in weight of copper and a t least five determinations in each case for the average gain in copper content of milk. The curve in Figure 1 is based on the average loss in weight of copper. The solubility of copper in milk increased with rise in temperature to a maximum a t 85" to 90" C. The break in the curve was probably due to the decreasing solubility of oxygen as shown by Speller,8 for the corrosion of iron in natural water. A
931
in Weight of Copper per Square Decimeter Surface
Exposed to Milk for 30 Minutes Av. LOSSIN Av. GAIN IN Av. LOSSIN Av. GAIN IN WT. OF COPPERCONTENT WT. OF COPPER CONTl3NT OF MILK TEMP. COPPER OFMILK TEMP. COPPER Mg. 0.258
OC.
30 35
0.301
50
0.516 0.671 0.860 1.032
40 45 55 60 65
"Corrosion: Cause and Prevention," p. 142 (1926).
1.118 1.333 9
Mg. 0.344
0.602
ME. 1.462
ME. 1.548
80
1.582 1.806
85 90 95 100
1.961 1.788 1.376
OC.
70
75
1.892
1,892 1.290 1.032
1.376
IND.ENG.CHEM.,19, 332 (1927).
Further Fumigation Tests with Ethylene DichlorideCarbon Tetrachloride Mixture' L. F. Hoyt LARKINCo., INC BUFFALO. h-. Y.
The food products after fumigation show different effects. Those rich in fat absorbed the fumigant appreciably but on exposure to the air gradually gave off the fumigant and beWO and one-half quarts (7 pounds) of 3:l mixture of came edible in from l to 8 days. Dried fruits and cereal in ethylene dichloride and carbon tetrachloride were used a tightly wrapped carton did not absorb detectable amounts for a 24-hour period, the temperature being maintained of the fumigant. a t 75" F. throughout fumigation. EFFECTS ON IxsEcTs-Flour infested with confused flour The materials fumigated were as follows: 1 bushel New beetle (Tribolium confusum) had been confined in R small York State white wheat in burlap sack; '/8 sack Gold Medal cloth sack and buried in the */g tied paper sack of Gold Medal flour, in paper bag, tied; sack Gold Medal flour, loose in flour. When examined within 1 hour after fumigation the an open fiber carton; seeds of wheat, oats, pea beans, raw 26 adult beetles and 5 larvae confined in the infested flour peanuts, and clover in open cartons; food products-bacon were all dead. KO reinfestation of this fumigated sample of wrapped and unwrapped, bitter chocolate, pmdered cocoa, flour has occurred during the 2 months it has been under obwalnut meats, shelled almonds, prunes, raisins, cream of servation since the fumigation. wheat cereal in tightly wrapped carton. Indian meal moth larvae and adult moths had been conThe infesting insects were: Tribolium in flour and Indian fined in a small carton of rolled oats which had been sealed meal moth in cereal. The fumigant was introduced into a and tightly wrapped. When examined within 1 hour after trough a t top of vault, so there was no direct contact of the fumigation the 24 full-grown larvae and 3 moths in the carton liquid fumigant with the substances fumigated on floor of vault all were dead. BAKIKG TESTS-on March 1, 1928, the fumigated wheat GERMINATION TESTSON SEEDSwas shipped by truck to the Olmstead Mills a t hledina, N. Y. WHEAT OATS BEANS PEANUTS C L O V E R % % % % % It was stored there for 5 days, milled into whole-grain graControl, not fumigated 86 85 74 42 86 ham flour, and shipped back to Larkin Co., Inc.. on March (CHzCl)z-CCla, fumigated 83 81 58 52 S5 8 in a paper sack along with a control sample of whole-grain There is no marked difference in germinating power be- graham flour milled from the same lot of wheat, not fumitween controls and seeds subjected to this fumigation. gated. A portion of flour made from the fumigated grain was transferred a t once to a tight container and the three OF ETHYLENE DICHLORIDE FGVIGATION ON FOODPROD- samples were kept in the laboratory until April 5, 4 weeks EI.FECT CCTSafter the fumigation. ----TASTE AFTER FUMIGAT~OX---11'2 24 3 8 Baking tests were made on the fumigated Gold Medal flour hours days days hours and on the whole-grain graham milled from fumigated grain, Bacon, urapped h'one Bacon, unwrapped Strong + Very faint + None with controls in both cases of flour not fumigated, by a laboWalnut meats Strong + Strong + Sone Almonds, shelled None .... ratory specializing in this work. Prunes h-one .... .... .. Fumigation of Grain, Flour, Foods, and Seeds in a 500Cubic Foot Plymetl Vault2
T
Raisins Cream of wheat Bitter chocolate (50% fat) Cocoa (25% f a t )
Trace
+
Strong f Distinct
+
h-one None Strong h'one
....
+
Faitit t
....
Received M a y 10, 1928 These tests were made in collaboration with H. Hughes of the Carbide and Carbon Chemicals Corporation. 1
kone
...
2
Conditions of baking: BasaD P~~~~~~ 3 / , Ibs. flour 3 0 s . sugar 1 qt. of water 1 "I sr1t 3 0%.yeast
3 ii~hleri~oonsful of m i l i d lard
hilixed by hand to a dough; placcd in raising pan, raised at temperature between SO" and 86" F. for 1 hour 30 minutes, to 1 hour 40 minutes. Worked by hand. Bliowed to stand at above temperature from 30 to 45 minutes. Again kneaded. Stood from 15 to 30 minutes. The temperature of the raising cuhirret brought to 90' F. and dough in regular baking pans kept at this tcmpcrature from 50 minutes to 1 hour and 15 minutes. Transferred t o oven and bakcd from 30 to 45 minutes st approximately 400~4;,0"I'.
were to be liauled up over pipes and left suspended in tlie room. Three strips of burlap 2 feet wide and 16 feet long and also a runner rug about 21/2 feet wide and 12 feet long m r e used. Clothes line was securely tied to tliese strips. The fumigant used was 10 gallons of etlrylene diehloridcmrlion tetraellloride mixture, a dosage of 14 pounds per 1000 cubic feet. This liquid was poured into a metal wadi tub, tlie burlaps and rug immersed in the fumigant and haded up oversterun pipes. The tlirceburlappieces, 2 x 16fert,bookup riot orer 3 gallons of tlie liquid, tlie lieavier rug absorlied perhaps another 3 gallons, and tlic resnairider was splashed onto tlie riign and floor of the room wii,li the aid of dippers.
G o m I\,IEDAL FLorn--'l'he baking tests on Gold M e d a l flour were made on Mardl 1 , 1928. The arerage volmne of two loaves from eaclr sample of Aour was determined and foimd to be as follows: cc.
. . . I, I.
,.c
I . , /.I
11, / I . , ! .
../
%,?.,, I , I
. :..:
I,
1
5%
. ..I.
1775
li8i lW23
Tile appeamnce of tlie loaves is sliown in Figore 1. There was no detectabic difference in the odor, texture, or general appearance of t i m e loaves. and although a faint. odor of fuinigant, could be deteet,ed in tlin tiour before use, the fumigant had Iiad no effect on the quality of the glutcn :mil coilld not be detected in the fiiiished loaf. Fieure 2- -Bread from Whole-Grain Graham Flour. Fumignted IB and C)and Nof FumiCarrd IA)
T h e experience of this fumigatioli indicated t i l e advisability of wearing a gas mask whilc di ibntirrg the fumigant in the .maimer doa:ribrd, as a stupefying eoricentration of the fumigant, quickly builds up in tlie room and there is danger of getting some of the fumigant in t,he face and eyes from the drips of t l i e burlaps as they are hauled up. T i l e door of tlic room was scaled with paper strips and F l ~ u r eI-Bread from Cold Medal Flour, Fumlgatod ( B a n d C ) silicat,e. It was impract,ic:il to secure a t,eniperature sodium and Not Fumigated (A) a1joi.e 65" F. a t this time, and the room mas l e f t sealed for %'€I~I,E-GR.~IN GRAHAMFLoulr-Baking tests on the whole- 44 hours. Live moth larvae from t.lrc rugs in the room liad hccn congrain graham flours were made April 6, 1928. T h e loaves fined in pill boxes--onc buried in an overstuffed davenport, from the three flours tested-i. e., (A) control, (B) flour from fumigated grain stored in t,ight. container, (C) same. the other placed in i h e rompart,ment of a umodeii piano stored in paper bag for 4 \veeks-%.ere all very small but could bench with the lid down. To kill t.he insects so protected not be differentiated in appearance or texture. KO odor of the fumigant would lrave to show unusual power of penethe fumigant could be detected in the hot loaf wlien broken tration. Tlie room was opened Saturday morning April 14 and it open-the most severe test. The appearance of the wholecould be entered: nithout a mask: within 15 or 20 minutes, grain graham loaves after cutting is shown in Figiire 2. altlirmgh it was not then sufficiently ventilated so that one could remain long. Examination of the insects showed: Fumigation of Moth-Infested Rugs and Furniture in 7800-Cubic Foot Room
The room was a furniture storage room (floor area 633 square feet, 121/4 feet high) with Pyrobar walls, concrete ceiling, and wood floor over cinders and concrete. The oiilg opening was an ordinary fire door about 7'/8 by 4 feet. The material to be fumigated consisted of miscellaneous household goods including numerous rugs of assorted sizes which were heavily infcstcd with the ordinary clothes motli, both adults and many larvae being present.. As many pieres of varnished u-nod furnitisre were included, it wns impracticable to scatter t.he liquid fumigant promiscuouslF about. the room, as had been done in the case of infested wheat germ. Hence it was decided to try a new method, in which bur1a.p &rips soaked with the fumigant
i n piano bench In davenpoif
u
la
a 5
5
7
5l 12
Thc insects tlrat were alive u,Iien removed from tho room were exceedingly sluggisli and, though provided with raw wool to fced on, they had been apparently poisoned beyond recovery b y tlie fumigant %lid soon died. Normal adult. larvae, not fumigat,cd, T\-hr:n transferred to raw nmol will fced and soon pupate. Exainination of the infested rugs on April 14 and again on -4pril 25 failed to sliow the presenre of any live insects. Hence this fumigation of furniture and rugs is to be eonsidered 100 per cent effective.
