April, 1944
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ANALYTICAL EDITION
Some Color Tests for Rotenone Not Specific H. L. HALLER
U. S. Department of Agriculture,
Bureau of Entomology and Plant Quarantine, Belbville, Md.
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F T H E several colorimetric tests proposed for the detection of rotenone (9), the blue color, or Durham, test (4) and the red color, or Grossdmith-Goodhue, test (6, 6) have been found especially useful. The Durham test is based on the observation that when rotenone is treat& with nitric acid and then with ammonia an evanescent blue calor is produced; i t has been modified by Jones and Smith ( 2 2 ) to make it more delicate and suitable for general use. I n the Grass-Smith-Goodhue test B red color is obtained when an alooholic potassium hydroxide solution containing sodium nitrite is added to rotenone and the mixture subsequently is acidified with SUlfUriC acid. Either test o m be relied upon to show the presence of rotenone or some of the rotenoids (IS) in spcimens of Derris, Lonchocarpus, and Tephrosia. The blue color test has h e n used by Jones et 01. (10) and by Sievers and associates (14) to select specimens of devil's-shoestring (TephTosia uirginiana) highest in rotenone content. Jones et al. ( I O ) found that the effectiveness against houseflies of acetone extracts of various species of Tephmsia is well correlated with the degrx of blue or blue-green color given by the Durham test. By this simple test the effectiveness of a sample of Tephroaia can be roughly predicted. Likewise, the red color test has been widely used in the quantitative evaluation of material containing rotenone and some of the rotenoids. Cahn et al. (8)found the method useful in a n extensive study of the composition of derris root. These c a l x tests, however, are not always specific for rotenone in other genera of Leguminosae. For example, in 1937 Moore ( I Z ) ) , searching for a domestic source of rotenone. reported its presenoe in Amrpha fmticosa because i t gave a positive Durham test. Subsequently F a t h e r l y (21, of Oklahoma Agricultural and Mechanical College, confirmed the observations of Moore and proposed that seed of the plant he used as a source of rotenone during the war emergency. More recently, however, Aeree, Jacobson, and Haller ( I )have shown that rotenone is not present in the seeds of A. frulicosa and that the blue color is produoed by a glycoside whose value as a n insecticide remains to be determined. The yam bean (Pachyrhizus eiosus) also was reported to contain rotenone solely on the hasis of the Durham test (8). Both this plant and Amrpha jmticosa give a positive red color test. Certain synthetic organic compounds have also been shown to produce an evanescent blue color when the Durham test is rtpplied (7). From the foregoing results i t appears that considerable oautiou should be taken in interpreting the color obtained in both these tests when they are applied to plant materid other than Derris, h b c n r p u s , and Tephrosia. Rotenone should be reported as present in plants only when i t has been definitely isolated and characterized. LITERATURE CITED
(1) Acree, F.. Jr., Jaoobson, M., and Hitller. H. L., J . Am. C h a . Soc., in press; Science, in press. (2) Agrioultural Insectioide and Fungicide Assoc., Bull. D23 (Oct. 7,1942). (3) Cahn; R. S.. Phipers, R. F., and Born, J. J., J. Soc. Chem. Ind. 57, 200 (1938). (4) Gimlette, J. D.,"Malay Poisons and Charm Cures", 2nd ed., p. 221,London, J. and A. Churehill, 1923. (5) Goodhue, L. D., J . Assoo. Oficial Agr. C h a . , 19, 118 (1936). (6) Gross, C. R.,and Smith, C. M., Ibid., 17: 336 (1934). (7) Harper. S.H.. J. C h a . Soc., 1942,595. (8) Hwang, S.-L., Kwangsi Agr.. 2 (4).269 (1941). (9) Jones, H. A,, U. S.Bur:Entomol. Plant Quer..Bull. ES63 (1942).
(10) Jones. H.A., Campbell.F. L.. and Sullivan, W.N., Soap. 11 (9) 99 (1935). (11) Jones. A. A.. and Smith, C.M., IND. ENQ.CHSX..ANAL.ED.,5, 75 (1933). (12) Moore. R. H..PuertoRiooEapt. Sta. Rept.. 1937. (13) Roark, R. C..J . E m . E n t m l . , 33,416(1940). (14) Sievers, A. F., Russell, G. A,, L o m a n , M. S.. Fowler, E. D.. Erlanaon. C . O., and Little, V. A,. U. S. Dept. Agr.. Tech.Bull. 595 (1938).
Washing Selas Filtering Crucibles by Reverse Flow ERWIN
J. BENNE
Michigan Agricultural Experiment Station, bst Lansing, Mich.
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INCE it has become impossible to obtain asbestos forandytical filtrations as desirable as that formerly available, the author and his associates have sought equally effective and convenient means of quantitative filtration without the use of asbestos. Selas filtering crucibles meet these requirements for certain determinations, including potassium by the chloraplatinate method, sugar by use of Fehling's solution, and others. These crucibles are similar to the Gooch type in shape but have a k e d , porous bottom for the filtering element, thereby eliminating the use of asbestos. Directions for cleaning recommend washing with hot water or hot acids by reverse flow in order to remove fine, insoluble particles lodged in the pores of the upper surface of the filter, hut do not suggest a convenient, mechanical means of accomplishing this; hence, the author devised the ar-
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Vol. 16, No. 4
INDUSTRIAL AND ENGINEERING CHEMISTRY
rangement shown in the accompanying figure to facilitate the
task. 1 is a Selas filtering crucible in position for being washed by reverse flow. 2 is a reservoir for the wash solution. It is arranpd to fit tiglitly around the bottom of thP crucible being waahed and can bp pxsily nnd quirkly transferred from one crucible to another. Thi3 exrhaneenblc ieservo~rwas vrevard from B large rubber pipet bulh by &tting off the top with a pair of YhmG and -king a hole i n ~ t h ebott&n with a iork borer: This hole must be of 3urh s i x that the h u h can be slipped over the end of thc crucible and Will fir snuelv moueh to wt3in the r a s h liquid. Used bulbs, deteriorated &"the p&t where they were
such a bulh. 3, yepared from a No. 9 rubber stopper holds the crucible safely m nosition for the effective annlicakan of suction. A eireula groove in the top of the stop.,ner accommodates the upper . . rim of the inverted crucihle. and if filled with water hefore inwiion 01 the crucible it providcs an effective seal against ~ntranceof air when suftion is applied. A large h d e in t h e eentcr of thi+ holder permits exit of the wuah liquid from the erueihlc into the suction fluqk. In order to ure n stopper nith a top l i r g ~ than r tlie mouth of thew erurihlcr, it was n & s m r y to redtire hnd taper the loner part to fit the nprk of t h e iiuctiuii Bask. From nnd d e views ul t l m I~w l d ~ r sare shuwn in the lower part of the ieture. The hole in the center of the stopper was cut with a co$ borer in the usual way; the groove in the top was made, and the lower part reduced, by use of a metal-cutting lathe. These devices used in combination with the arrane;ement shown for holding the suetion Rark.i and trap bnttlp provide il convenient incans for warhing Selas erueihles by reverse How. After x crucible is wwbed several times in this r 3 v . it is Dlaecd in the ordinary crucible holder shown in the suction"fla& acthe right for washing in the usual direction. ~
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ACKNOWLEDGMENT
86 on Diecast Met&
and
D-4 on Road and Paving M a t e
B-7 on Light Metals and Alloys B-8 on Electrodeposited Metallic coatings C-16 on Therhal Insulating Materials D-1 on Paint, Varnish. and Related Products D-2 on Petroleum Products and Lubrioants
D-5 on Coal and Coke D-9 on Electrical Insulating Materials (Philadelphia, Pa., Feb. 21.22) D-11 on Rubber Products D-17 on Naval Stores D-20 on Plastics (Philadelphia. Pa., Feh. 23, 24)
rials
AkY8
NEW EQUIPMENT Instrument for Measuring Small Particles The Fisher sub-sieve siaer, for measuring the size of partides too small to be measured by sieves, is based on the apparatus described by Gooden and Smith [Im. ENO.C n m ~ .ANAL. , ED.. 12,479 (194a)], and is made by Eimer &Amend. 635 Greenwich St., New York, N.Y. Operstiotion has been simplifiedand B calculator chart provided to make operation easy. The instrument consists of an air pump, air-preasure regulating device. precision bore sample tube, double range flowmeter. calculator chart, and accessory equipment. In owrauior,the motor-driven air pump builds up pressure in the pressure regulator to .e constant head, so that a uniform flowof dry air passea through the packed powder sample and is measured by means of a double range flowmeter. The liquid level in the manometer varies with the air flow. depending on the resistance (particle sine) of the particular sample. The werage particle size of the shmple in microns is read directly from the chart 84 indicated by the level of the fluid in the manometer. The range of the instrument is from 0.2 to 50 microns.
The author is indebted to Wm. Wall.llsee, mechanic in the Department of Agricultural Engineering at Michigan State College, for operating the lathe in the preparation of a number of these crucible holders.
A.S.T.M. Holds 1944 Committee W e e k in Cincinnati, February
28 to March 4
Capacitor for Electron Microscope A 0.01-mfd. 40,000-volt direct current capwitor hss been built for a speoial spplioation of the electron microscope. l t is cspahle of o o n t i n u o u s operation st 80' C. and of withstanding total submersion and heavy surges. The case is welded steel measuring 4'Vm x 53/4 X 7 inohes high with a standoff insulator 8.5 inches high, soldered direotly to the ease. thus eliminating the posaibility of oil leakage or the entrance of moisture. I t is manufactured by the I n d u s t r i a l Specialty Co.. 1725 W e s t N o r t h Ave., Chicago 22, Ill.
Lead Standard The Ameriean,Standards Association has announced approval of
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new standard. Allowsble Conoentration of Lead and Certain In-
A-1 on Steel A-3 on.Cast Iron A-5 on Corrosion of Iron and Steel
A-6 on Magnetio Properties A-7 on Mslleable Iron Castings
A-10 on Iron-Chromium. IronChromium Nickel, and Related Allovs B-3 &Corrosion of Non-Ferrous Metals and Alloys B-5on Copper and Copper Alloys
organic Compounds (237.11-1943), which sets s& limits for the amount of metallic lead, lead carbonate, lead sulfate. lead oxides, lead nitrate. and lead chloride allowable in the air of industrial workshops. I t mvem the physical and chemical properties of the substsnce, summarizes methods of test, and includes a comprehensive bibliography. Copies may be obtained from the American Standards Assooiation. 29 West 39th St., New York 18, N. Y., at 20 cents each.
