V O L U M E 2 4 , NO. 9, S E P T E M B E R 1 9 5 2 Table I. Constituent Analyses of Asphalt from Tampico, RIexico, by Use of ,iluminas from Alpha-Alumina Monohydrate _
condition^ for Dehydration of Alpha-Alumina _ Monohydrate ~ to 4lrimina Quantity Temp , Heating OC period nun treated, grams
Resin Content of Asphalt, %"
1491
analyses of thc asphalt by use of tlic initial lot of anhydrous alumina (4). The blend was then used for the constituent analysis of a low-asphaltene-t>Te asphalt from crude oil from Kern River, Calif. Based upon this asphalt, the alumina blend was less adsorbent than the alumina used in the initial analyses. This shows that, although a blend of alumina can beprepared that has siniilar adsorption characteristics to another alumina in analyses of a given asphalt, these aluminas may exhibit dissimilar adsorption characteristics in analyses of a different type of asphalt. .ACKNOWLEDGMENT
Average deviation =0.4370; former analysis of asphalt: 29.8% asphaltenes, 42.3% oils and 27.77' resins ( 1 9 ) . a
1 & O j 0.05 to 0.09, and 0.16 to 0.51, respectively, the results were not consist'ent enough t o measure the adsorbability of the alumina samples. Under certain heating conditions, alpha-alumina monohvdrate is converted t o variouh crystalline forms of anhydrous alumina (f-3,6 , 7 , 11, I S ) . To prepare products having different adeorption characteristics, samples of alpha-alumina monohydrate were heat,ed for periods raiiging from 10 minutes to 18 hours a t t,emperatures of 700" t o 1200" C. +Is shon-n in Tahle I, a yield of 36.0% resins vivas obtained from an asphalt of crude oil from Tampico, LIrtsico, by using an adsorbent prepared by heating 140 grams of alphn-:Lluinina monohydrate in a muffle furnace a t 1050" C. for 50 minutcs. By hcatiiig smaller samples, or by heating samples a t higher temperatures or for longer periods, the alpha-alumina moiiohydrate was converted into less adsorbent products containing greater proportions of anhydrous alpha-alumina. This dehydration process was very susceptible t o changes in the quantity of sample heated and to minor changes in the heating conditions. Accordingly, the adsorpt'ion characteristics of the products iverv not sufficiently reproducible for t,he analysis of asphalt. -111 anhydrous alumina adsorbent that was suitable for the constitueiit analysis of a standard asphalt sample from crude oil from Tampico! Llexico, was prepared by blending aluminas having higher and lower degrees of adsorption. Const'ituent analyses made ivith this blcmtl agreed n-ith values obtained in previous
Work was done under cooperative agreement between the University of Wyoming and the Bureau of Mines. Special acknowledgment is made to the Fisher Scient,ific Co. and to the Aluminum Co. of .Imerica for their cooperation in providing samples of alumina; also, t o H. S . Smith and Howard H. Heady, who assisted in making the petrographic and x-ray diffraction analyses. LITERATURE CITED
( 1 ) Beletzkii, AI. S., Legkie ;Metal (C.S.S.R.),5 , KO.2, 16-21 (1936).
( 2 ) Gorbunova, 0. E., and Vaganova, L. I., Khim. Referat. Zhur. (V.S.S.R.).2, NO.5, 31-2 (1939). ( 3 ) Heineman, H., Krieger, K. A, and AIcCarter, W. S. W., Ind. Eng. Chem., 38, 839-42 (1946). (4)
Hubbard. R . L., and Stanfield. K. E., ~
A
L
CHEJI., . 20, 460-5
(1948). (5) Ihid.. C. S . Bur. Mines, R e p t . I n r e . s f . , S o . 4523 (1949). ( 6 ) Jellinek, & H., I.and Fankucheii, I., I n d . Eng. Chem., 37, 15863 (1945). ( 7 j Ibid., 41, 2259-65 (1949).
(8) Kommes, (9) (10)
(11) (12)
(13)
W. C., and Stanfield. IC. E., Proc. Assoc. Asphalt Pacing Technol., 20, 473-89 (Febiuary 1951). >lair, B. J . , and Foraiati. A. F., J . Reseurch, S u t l . Bur. Standards, 32, 165-83 (1944). hlair, B. J . , Xesthaver, J . \I-., and Rossini, F. D., I n d . Eng. Chem., 42, 1284 (195Oj. Xoiin, R . , G e d . F o w n . i. Stockholm Fo Stanfield. K. E., and Hubhard. R. L., Paper, KO 717 (1949). Stumpf, H. C . , Russell, A . P., Sewaome, J . W., and Tucker, C.M., 1nd. Eng. Chr'm., 42, 1398-403 (1950).
RECF:IVED for review l f a r c h 20, 1952, Accepted June 9 . 19.52.
Sulfamic Acid as a Standard Reagent for Alkalimetry W. F . WAGSER, J. A. WCELLSER,
AND
C. E. FETLER'
C-niuersity of Zcentucky, Lexington, Icy.
HE use of sulfaniic acid as a standard of reference in alkaliinretry has increased rapidly in recent years after its suitability for this purpose was reported by Butler, Smith, and Audrieth (1). At room temperature, solutions of sulfamic acid hydrolyze slowly, but as suggested bj- these authors a const,ant acid titer should be maintained because the hydrolytic product is the hydrogen sulfate ion LThich contains only one releasable proton. The present investigation was undertaken t o verify that solutions of sulfaniic acid retain a constant acid titer and t o study the use of sulfamic acid as a st,andard titrant for alkalimetry. Sulfamic acid may he compared with hydrochloric acid and sulfuric acid, for use as a standard solution. Reagent grade SUIfamic acid may be obtained at a modest price from the G. Frederick Smith Chemical Co., or t'he technical grade may be purified easily (1). It, is readily soluble in water, forming a st,rong acid only slightly weaker than sulfuric and hydrochloric acids and can be titrated with bases using indicators with transition ranges h ? t w w n a p H of 4 to 9. The pure solid acid is nonhygroscopic; r
1
Present address, S . i C . 1 , Leivi? Flight Propuiaion Laboratory. Cleveland,
Ohio.
thus a solution of known concenti,ation may he prepared easily by dissolving an accuratelJ- Reighed sample and diluting t o a known volume. Pract'ically all salts of sulfamic acid are soluble, thus eliminating the interference of precipitates during a titration. h possible objection t o the use of sulfamic acid lies in its relatively low molecular weight. REAGENTS
Sulfamic Acid, standard of reference for alkalimetry, G. Frederick Smith Chemical Co. Sulfamic Acid, reagent grade, G. Frederick Smith Chemical Co. Sodium Carbonate, anhydrous, primary standard grade, 1Iallinckrodt Chrmical Works. Acid Potassium Phthalate, National Bureau of Standards. Modilled Methyl Orange Indicator, aqueous solution, prepared by method of Hickman and Linstead ( 2 ) . Bromothymol Blue Indicator, aqueous solution, 0.1 %. EXPERIMENTAL
Stability of Sulfamic Acid Solutions. Six liters of approximately 0.1 A; solution were prepared by dissolving reagent grade sulfamic acid in carbon dioxide-frec distilled water. Six liters of approximately 0.1 N carbon dioxide-free sodium hydroxide solu-
ANALYTICAL CHEMISTRY
1492 Table I. Analysis of Pure Sodium Carbonate S a K O a Taken, Gram 0.0714 0 1004 0 1044 0 2068 0 2230 0 1730 0.1742 0 2000 0 2000 0 2000 0.2000
XatCO, Found, Gram 0 Oil4 0 1008 0 1046 0 2069 0 2230 0.1726 0 1740 0.2000 0 2003 0.2003 0.2002
Error,
Error 0.0000 +o. 0004 0.0002 +0.0001 0 0000 - 0.0004 -0 0002 0,0000 +o. 0003 0.0003 +0.0002
+
+
% 0.00
+0.40 +0.19 +o 05 0 00 -0.24 -0.11 0.00 +0.15 +0.15 t0.10 Average 0.18
Table 11. Analyses of Soda Ash Samples XalCOa, Sample 1 2
%
NazCOa Found,
%
29.82 45.66
29.82
No. of Detns. 4
.4verage Error,
%
0 12
tion were prepared. Both solutions R-ere laced in borosilicate glass storage bottles protected from the carEon dioxide of the air by tubes containing Ascarite. T h e solution of sodium hydroxide wm standardized using potassium hydrogen phthalate. The volumetric ratio of sodium hydroxide to sulfamic acid was determined a t varying time intervals over a period of 7 months. T h e sodium hydroxide was restandardized each time the ratio of the bme to sulfamic acid was determined. The normality of t h e sodium hydroxide remained constant for t h e duration of the tests, T h e ratio wm determined by t h e folloaing procedure: Twenty-five milliliters of the sulfamic acid were pipetted into a 300-ml. Erlenmeyer flask and diluted to about 100 ml., 2 or 3 drops of bromothymol blue indicator were added,.and t h e solution was titrated t o the end point with standard sodium hydroxide solution. The ratio of the base to the acid remained constant within
experimental error for a period of 213 days. The average ratio of 45 determinations was 1.123 with a standard deviation of 0.0014. After 6 days the sulfamic acid gave a slight test for SUIfate upon the addition of barium chloride. A progressively stronger test for sulfate was obtained as storage time increased. Analysis of Soda Ash Samples. Since a sulfamic acid solution maintains a constant acid titer during storage, its use as a standard solution for analysis of soda aqh samples n a s investigated The solutions of acid of knoivn normality R ere prepared by dissolving accurately weighed portions of the acid in distilled water and diluting to volume in calibrated volumetric flasks. T h e following procedure was used to analyze samples of primary standard grade sodium carbonate. The sodium carbonate was dried a t 110" C. for 1 hour. A 0.3gram sample was weighed accurately, transferred t o a 300-ml. Erlenmeyer flask, dissolved in about 75 ml. of distilled water, and titrated with 0.1 W standard sulfamic acid solution using modified methyl orange indicator. A blank correction of 0 06 ml. was applied to each titration. The results of t h e analyses of pure sodium carbonate are shown in Table I. T h e first five results were obtained using sulfamic acid of grade listed as standard of reference for alkalimetry. T h e rest of the results were obtained using reagent grade sulfamic acid. I n order to test the method for the analysis of impure samples, several Thorn Smith analyzed samples of soda ash were carried through the above procedure. Standard solutions of 0.1 N sulfamic acid were prepared hy direct v-eight and the calculated normality used without standardization. Results of these analyses are shown in Tahle 11. LITERATURE CITED
(1) Butler, hf. J., Smith. G. F., and Audrieth, L. F., IKD. ESG. CHEX..ANAL.ED.. 10. 690 (1938). (2) Hickman', K. C. O., and Linstead, R . G., J . Chem. Soc. (London),
121, 2502 (1922).
RECEIVED for review February 21, 19.52. Accepted J u n e ?, 195%.
Rapid Method for Determination of Small Amounts of Zirconium RALPH E. OESPER
AND
RAYMOND A. DUNLEAVY', University of Cincinnati, Cincinnati, Ohio, AND JOSEPH J. KLINGENBERG, Xacier University, Cincinnati, Ohio
H E R E is need for a more rapid convenient method for the 'direct determination of small amounts of zirconium in various commercial materials. I n 1947 Kumins ( 7 )introduced mandelic acid as a highly selective reagent for zirconium. Later, Hahn ( 5 ) showed that mandelic acid also precipitates hafnium quantitatively.' Gavioli and Traldi (4)applied the Kumins mandelic acid method t o the determination of zirconium in steels. Oeaper and Klingenberg ( 8 ) , after testing a number of glycolic acid derivatives, concluded that the zirconium precipitating action of the (-CHOH-COOH) group is retained jn compounds other than mandelic acid. The introduction of an azo group into the mandelic acid molecule would be expected t o produce a reagent which M ould form a colored precipitate with zirconium, thereby conferring increased sensitivity to the reaction. I n addition, the presence of color r i g h t be utilizable in a colorimetric method of detern ination. Consequently, the present investigation was directed toivard: ( a ) s>mtliesis of a suitable azo derivative of mandelic acid, ( b ) determination of the necessary conditions for the precipitation, (c) investigation of the interference of other elements, and ( d ) development of a usable procedure. SYNTHESIS O F RE4GEVTS
m-Kitrobenzaldehyde (Eastman) was selected as the starting compound in the synthesis of azomandelic acid derivatives. mXitromandelic acid was prepared from this compound by a cyanhydrin synthesis (6). The method of Heller nas found to be 1
Present address, Drackett Co., Cincinnati, Ohio.
generally suitable but the crude material had to be purified as follows: A solution of 30 grams of the crude m-nitromandelic acid in 300 ml. of warm water was cooled and poured into a 500-ml. separatory funnel. The brown oily impurities that srxttled were run off and the remaining solution v a s extracted ivith three 50-ml. portions of ether. Upon evaporation of the ether extract the purified m-nitromandelic acid remained as a light yellow oil, which solidified on cooling and scratching. .liter drying over sulfuric acid in an evacuated desiccator, a pure white product was obtained with a melting point of 119" to 120" C. The na-riitromandelic acid may be further recrystallized from benzene or toluene. Reduction of the m-nitromandelic acid by the ferrous sulfatebarium hydroxide procedure (6) yielded m-aminoniandelic :!rid. An alternative reduction procedure employing a modification of the method of Fredga and dndersson ( 3 ) vias developed. mXitromandelic acid was reduced in ethyl alcohol solution over a platinum oxide catalyst in a Parr low pressure hydrogenation apparatus. Pure m-nitromandelic acid (10 grams) and 0.1 gram of plat'num oxide were placed in the reaction bottle of a Parr hydrogenation apparatus (Model C.A. KO.278). The reaction bottle was filled ttyo thirds x i t h ethyl alcohol and placed under vacuum until most of the air was removed. Hydrogen was bled int'o the bottle until a gage pressure of 59 pounds was shomm. The required pressure drop was noted in approximately 1 hour. Atmospheric pressure was then restored. The platinum oxide v,m filtered off and the ethyl alcohol evaporated on a steam bath. The residue vias then recrystallized from the least amount of hot water. The nt-aminomandelic acid melted a t 129" to 130" C. and was obtained in 50% yield. This procedure proved to be moi'e sati3factory than the ferroue sulfate-barium hydroxide reduction. The resulting amino derivative wa8 diazotized and coupled n-ith either a phenol or an aro-
