V O L U M E 2 3 , NO. 11, N O V E M B E R 1 9 5 1 Table 111. Analysis of .41uniiniim-Containing Sample by Fluoride Method liaterial
Aluitiinntn bronze
-4luminum Present,
Aluminum Found,
10 40
10 26, 10 32, 10 60, 10 42 11 11 9 80,9 91, 9 80
11 03
Zinc-base die-caatiny alloy
ro
%
9 77 3 48 3.64 9.36
5,34 3.60 9 20
Reinaik.i
Fe 3 36L Fe: 3 1 7 d M n , 1 0%
cu, 3 %
Initial weight, I g. Thiourea, 2 inl.
Table IV. Analysis of .-iluniinum Bronze bl Fluorescence Jfe thod liaterral hluminuni bronze
.4luininuin Prescn t,
Aluniinuiii Found,
10.39
I O . 20
70
9 . 76
PO
4
:n
9.20
9 20
T1.03
11 03 11 39
11.03
iron, calcium, m:tgneaium, leiid, and tin. Of these elements, copper-aluminum alloys usually contain only iron, lead, and tin. The fluoride methods describetl in the literature require potentiometric equipment (2,4,13,14) or the separation of interfering elements (12). T o avoid these requirements a suitable indicator was sought for titrating aluminum with fluoride in the presence of copper. Iron salicylate was found to be satisfactory, as the determination of iron in the presence of copper wit,h sodium salicylate is made in the same pH range Then titrating both aluminum and iron with fluoride ( I , 8). I n acid solution copper can be masked with thiourea (6, 7 ) . dfter extensive preliminary u-ork, the following procedure was developed.
Fivetenths gram of aluminum-bronze is dissolved in a 500-ni1. wide-mouthed Erlenmeyer flask with a small amount of hydrochloric acid, adding dropwise 30% hydrogen peroxide. The eolution is made strongly ammoniacal, and hydrogen peroxide is removed. The precipit,ate is dissolved with 1 to 1 acetic acid, using 6 ml. in excess. If much iron is present,, the precipitate is dissolved with glacial acetic acid, wing 25 ml. in excess. Twenty milliliters of R-ater and ‘50 nil. of Cellosolve or Carbitol are added. Then the solution is saturated with sodium chloride and 5 ml. of 10% sodium salicylate and 20 nil. of saturated thiourea solution are added. If necessary, one drop of 0.1 M ferric chloride is used a8 an indicator and the solution is immediately titrated with 0.6 -I1sodium fluoride until the red eolor is dixharged.
1691
The sodium fluoride is standardized against a standard aluminum solution or a standard alloy sample; 1 ml. of 0.600 AI sodiuni fluoride = 2.697 mg. of aluminum. -4s iron and aluminum are both titrated with sodium fluoride, in alloys containing iron, the iron must be determined independent,ly and deducted from the aluminum found by sodium fluoride titration (1 mg. of iron = 0.48 mg. of aluminum). Lead and tin, if present, must be removed before titration. The method permits determination of aluminum in alumiiiunibronze in as little as 5 minutes. Table I11 shows some typical reEUltP. Colorimc~tricdeternlination of aluiiiiiiuni with nioriu has beeii used ( 9 , I . i ) . The interference of fluorides in the aluminuni-morin reaction suggested that aluminum could be titrated with sodiuni fluoridc in the presence of niorin to the disappearance of fluorescence in ultraviolet light (9). The following procedurr \yay developed. The sample is dissolved as in the previous procedure, in a transparent silica flask, then made ammoniacal, and the precipitate is dissolved with acetic acid using 25 ml. in excess. Then 2 ml. of 1% gum arabic, 50 ml. of methanol, and 10 drops of morin solution (0.4 gram per 100 nd. of methanol) are added. The solution is titrated with sodium fluoride to the disappearance of fluorescence in ultraviolet light. The method permits the debermination of aluminum in the presence of iron. Table IV gives mnie typicsl rwults by this method. LITERATURE CITED
(1) Ani. SOC.Testing hIaterials. “Chemical Analysis of Metals,” p. 343, 1946. (2) Farkas, L., and Uri, N., ANAL.CHEM., 20,236 (1948). (3) Heceko, T., Chem. Z . , 58, 1032 (1934). (4) Ivanov, B. G., and Hezjajko, 8. I f . , Zuvodslcaya Lab., 15, 511 (1949). (6) Kinnunen, J., hfelallu.ETZ,41, 158 (1944). (6) Kinnunen, J., Melallurgia, 37, 153 (1948). (7) Lange, B., “Kolorimetrische Analyse,” p. 185, Berlin, Verlag Chemie, 1941. (8) Mehlic, J. P., IND. ENG.CHEM., . \ N . ~ L . ED.,10, 136 (1938). (9) OkaE, A., Colkction trav. c h i n [ . tschecoslm., 10, 177 (1938). (10) Pigott, E. C., J . SOC.Chem. I?&., 58, 139 (1939). (11) Reutel, C., M e l a l l u. E m , 8, 170 (1941). (12) Ringborn, A., Sverisk Papperstidn., 50, 145 (1947). (13) Saylor, J. A., and Larkin, M . J3.,ANAL.CHEM.,20, 194 (1948). (14) Treadwell, W. D., and Bernwconi, E., Helv. Chim. dctu, 13, 500 (1930). (15) Khite, C. E., and Lowe, E. S..INO.E m . CHEM.,Ax.4~.ED.,12, 229 (1940). R E C E I V ESepteuiber D 10, 1950.
Determination of Testosterone Propionate in Vegetable Oil Solution JA3IES J. JIADIGAK, EMANUEL E. ZENKO, AYD RICHARD PHEASAR?‘ Schering Corp., Bloomjield, ,V. J .
r l I I E a m y of conimercial prepuxtions of steroid hormones in
( 8 ) to the n-zay of s c w e oil solutions of pregnenolone acetate.
vegetable oil solution has been IL problem for many years. The inclusion of a biological assay method for testosterone propionate injection (sterile solution in vegetable oil j in t,he fourteenth revision of the United %ate8 Pharmacopeia was due to the lack of an analytical method for the determination. The publicat,ion bl- Klein et al. ( I ) of a method for the quantitative deterniinntion of progesterone by the isolation and identification of the bis-2,4-dinitrophenylhydrazonu, from oil solutions, led the authors to believe that a similar method might be applicable to solutions of testosterone propionate. When experiments with the 2,4-dinitrophen~lhy(lrazoiieof tcistosterone propionate failed to yield quantitative recoveries, attention was turned to the formatioil of the semicarbazone, a method which had been successfully applied by two of the authors
,4 satisfactory method has been developed whereby the testosterone propionate is quantitatively separated as the seniicarbazone, n hich may be weighed and identified by its melting point (with characteiistic color change), or by ultraviolet absorption REAGENTS USED
Seniicarbaxide acetate, 0.225 JI is prepared by refluving together, foi. 2 hours, 2.5 grams of semicarbazide hydrochloride, 2.5 grama of anhydrous sodium acetate, and 30 ml. of methanol. The solution is then chilled and filtered to remove sodium chloride, and the filtrate is adjusted with methanol to a volume of 100 ml. The iso-octane (2,2,4-trimethylpentane) used in this work conformed to the U.S.P. XIV reagent specifications. The petioleum ether used was hlerck’s purified, boiling range 30” to 75’ C.
1692
ANALYTICAL CHEMISTRY 50 mg. of testosterone
Table I.
Soliltion
D
n
E E F F
G G
n
c
Determinations of Testosterone Propionate
Labeled Strength, Rlg./hII.
25 25 25 25 25 25
5
5 5
5
Vehicle
benzyl alc Sesame oil Sesame oil Sesame oil Sesame oil Sesanie oil Sesame oil Sesame oil Sesame oil Sesame oil Sesame oil
Found. Mg.,'Ml.
24 23 24 24 24 23 4 4 5 4
Found.
Melting Range of Derivative,
96.1 95.1 99.5 99.5 99.7 95.1 90.9 98.5 101 2 Y-l 4
209-210 209-210 21 1-212 211-211 2 15-2 1ti 2 15-2 16 212-213 208-209 108-209 207-208
02 78 88 88 93 78 545 925 060 720
%
c.
TESTOSTERONE PROPIOSVATE SEMICARBAZONE
Five hundred milligranis of testosterone propionate U.S.P. were dissolved in 15 ml. of methanol and added to 15 ml. of 0.225 111 semicarbazide acetate solution. The mixture was refluxed for 2 hours, cooled t o room temperature, and precipitated with 400 nil. of chilled water. The precipitate was filtered off, washed neutral with water, and dried to constant weight a t 105" C. The yield was 578.4 mg., or 99.3%oof theoretical: melting point (capillary inserted in bath a t 200 , bath temperature raised 3" per minute) 215-216" corrected. Part of this material was recrystallized from benzene-petroleum ether (about 1 to l ) , giving off-white crystals melt,ing a t 215216" corrected by the above method, and a t 212-213" correcte; with the method modified by reducing the rate of heating to 1 per minute; [oljYo = +190 (lye dioxane). These and all other melting point determinations of this substance were characterized by decomposition and by a bright red color in the melt. A sample of the recrystallized seniicarbazone gave the following analysis: calculated: for C23H350313: carbon, 68.82; hydrogen, 8.78; nitrogen, 10.47. Found : carbon, 68.67; hydrogen, 8.75; nitrogen, 10.27. The ultraviolet absorption spectrum was.determined in a 0.001% solution in methanol, in which maximum absorption occurred at 268 to 269 mg (specific absorption, E = i25 i 5%) and neg1igil)le a1)sorption from about, 320 m p upward. Testosterone propionate seniicarbazone was found to be soluble in acetone, alcohols, ether, benzene, chloroform, pyridine, and acetic acid. It is insoluble in water and iso-octane, and very slightly soluble in petroleum ether.
;7m,
ASSAY PROCEDURE
If the solution to be tested contains less than 10 mg. of testosterone propionate per ml., a sample is measured which contains
ropionate. This is mixed with 40 ml. has been saturated with 90% ethanol. The petroleum ether solut,ion is extracted with eight 15-ml. portions of 90% ethanol which has been saturated wit,h petroleum ether. [This extraction method is based on t,he U.S.P. XI\method for progesterone injection, and includes the modification propowd by Umberger ( S ) . ] The combined alcohol extracts are then evaporated to dryness; the residue is transferred, with the aid of a little methanol, to a 25- to 50-ml. round-bottomed flask, and treated R-ith semicarbazide acetate solution and worked up in the manner described below. If the oil t o be t,ested contains 10 mg. or more of testosterone propionate per nil., a sample containing 50 mg. is accurately measured. This is placed in a 25- to 50-ml. round-bottomed flask x i t h 3 ml. of the 0.225 A I semicarbazide acetate solution; the mixture is refluxed for 2 hours and cooled to room temperature. Ten milliliters of iso-octane are added and the resulting solution is poured into 100 nil. of ice cold water. A little methanol is used to rinse the flask. The mixture is thoroughly stirred and allowed to stand, cold, for 2 t o 3 hours. The hydrocarbon layer is not separated; the entire mixture is filtered through a tared, medium porosity, sintered-glass filter, and the precipitate is washed with iso-octane, sucked dry, and washed with water. The precipitate is again sucked dry and then dried to constant weight in an oven a t 105". The assay is calculated as follows:
of petroleum ether whic!
Llg. of semicarbazone recovered 344.48 x 401.3.3 - y = ml. of samplc mg. of testosterone propionate per nil. ~~
~~
The melting point of the recovered seniicarbazone should be between 207' and 217" corrected, when determined in a bath heated at 3" per minute, with the capillary inserted :Lt 200" C. Table I shows results obtained with various commercial samples of festosterone propionat,e injections. ACKNOWLEDGMENT
The authors x-ish to thank Wilbur S. Felker, quality control manager, and Felix J. Pheiffer, analytical laboratory manager, for their encouragement and assistance in the execution of t,his ivork, Bradley Whitnian of the Chemical Research Divipion for advice and suggestions, and Edwin Comer of the Chemical Research Division for the microanalytical tlet.ermiriatioii. .LITERATURE CITED
(1) Klein, D., Weher, S . ,and Gordon, S.AT., A ~ I .CHEJI., . 20,1746 (1948). (2) Pheasant, R., and Zenno. E. E., unpublished research, (3) Umberger, E. J., J . A m , Pharm. .4ssoc., Sci. E d . , 36,700 (1950). RECI:I\-F.D .\pril 3 . 1H:l
Plasticizer Quality Test CARL .J. \IAL\l,
LEO B. GENUNG,
AND
MhURICE L. TOWNSEND
Eustman Kodak Co., Rochester, N.
L-UTICIZERS used in films, lacquers, plastics, and hot Pnielt coating compositions should not contribute to the breakdown or discoloration of the product under the conditions encountered in formation, application, and use. It is desirable, therefore, t o test plasticizers for their suitability for the purpose intended. In some cases, the test is made by mixing the plasticizer with :L cellulose ester, resin, etc., heating, and observing the change in color or some critical physical property. Salts, acids, or other impurities introduced during manufacture of the polymer may diminish or accentuate the results of the test. These impurities may vary from batch to batch of the polymer and, therefore, prevent a reliable test of the quality of the plasticizer. I n other cases, plasticizers may be tested by determining some undesirable component, such as sulfur when sulfuric acid has been
Y.
used as catalyst in the manufacture of the pljsticizer. The revult may or may not give an accurate indication of the quality of the plasticizer. An independent test is desired which can be applied to the plasticizer, and which is a simple, sensitive, and direct measure of objectionable impurities. The following test was found to fulfill the requirements acceptably. THE TEST
Procedure. Place 5 ml. of the plasticizer in an 18 X 150 nini. borosilicate glass test tube and insert a 0.5 X 2 inch (1.25 X 5 em.) strip of ashless filter paper (Whatman No. 42 was used for the experiments described). The strip is thus about half immersed. Heat the tube and contents unstoppered for 1 hour in an oil bath a t 180" C., and examine the filter paper for discoloration, which indicates the presence of undesirable impurities.
