INDUSTRIAL AND ENGINEERING CHEMISTRY
284
Identification of 2-Aminoethanol
TABLE VIII. ANALYSISOF KIDNEYFOR LEADBY DIPHENYLCARBAZIDE METHOD NO. 1 2 3
4 5
'j
69
Normal or Unexposeda Mg./100 g.b 0.54 0.55 0.58 0.58 0.58 0.58
0.63 0.68 0.74 0.74 0.90 1.10 1.10
No.
Lead Poisoning Proved or Suspected
16 17 18
19 20 21 22
1.50 1.62 1.65 1.70 2.22 2.27
4.10 4.51
23 4.60 24 10 5.00 11 25 5.33 26 12 5.80 27 7.69 13 14 2s 14.00 1.13 0 No recorded symptoms attributed t o lead and no known recent exposure. b Mg. in 100 grams of whole dry kidney, medial slice, including cortex and medulla.
of the dithizone method has steadily increased confidence in the new procedure. Experience indicates that the method is suitable for use as a diagnostic aid in establishing the presence of lead poisoning or absorption of lead.
Literature Cited (1) Assoc. Official Agr. Chem., Official and Tentative Methods of Analysis, 1935. (2) Cazeneuve, P., Bull. SOC. chim. Paris, 23, 701 (1900); 25, 761 (1901). (3) Cholak, J., Hubbard, D. M., McNary, R. R., and Story, R. V., IND. ENG.CHEM., Anal. Ed., 9, 488 (1937). (4) Fairhall, L. T., Am. J . Pub. Health, 28, 825 (1938). (5) Fairhall, L. T., J. B i d . Chem., 60, 485 (1924). (6) Fairhall, L. T., J . I n d . Hyg., 15, 289 (1933). (7) Funk, H., and Schormiiller, J.. 2. anal. Chem., 82, 361 (1930). (8) Groger, M., Ibid., 54, 192 (1907). (9) Horwitt, M. K., and Cowgill, G. R., J . Biol. Chem., 119, 563 119371. , (10) Jones, B., Analyst, 55, 318 (1930). (11) Kaplan, E., and McDonald, J. M., J . Phum. E x p t l . Tharap., 63, 17 (1938). (12) Karaoglanov, Z., and Michov, M., 2. anal. Chem., 103, 113 (1935). (13) Kehoe, R. A., Thamann, F., and Cholak, J., J . Ind. Hyg., 18, 42 (1936). (14) Lachaud, M., and LePierre, C., Compt. rend., 110, 1035 (1890). (15) LetonoR, T. V., J . Lab. Clin. Med., 20, 1293 (1935). (16) Riggs, H., Letonoff, T. V., and Reinhold, J. G., unpublished. (17) Sanford, A. H., Sheard, C., and Osterberg, A. E., Am. J . Clin. Path., 3, 405 (1933). (18) Smith, F. L., Rathmell, T. K., and Marcil, G. C., Ibid., 8, 471 (1939). (19) Willoughby, C. E., and Wilkins, E. S., J . Biol. Chem., 124, 639 (1938).
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PRESENTED before the Division of Biological Chemistry a t the 97th Meeting of the American Chemical Society, Baltimore, Md.
Mortar and Pestle for Powdering Glass H. L. WUNDERLY, Renziehausen Laboratory, Children's Hospital of Pittsburgh, Pittsburgh, Penna.
A
BERKHARD KEISER Tretolite Company, St. Louis, 310.
M g . / i 0 0 9.6 15
N INEXPENSIVE, convenient, and safe mortar and
pestle for powdering glass have been devised in this laboratory. T h e mortar consists of 5 inches of 1-inch iron pipe (nipple), on one end of which is screwed a pipe cap, loosely fitted in order to facilitate removal of the powdered glass. T h e pestle is a 16-inch length of 0.75-inch iron rod, threaded at one end and fitted with a large iron nut having a diameter a little greater than 1 inch. The n u t is tightly adjusted t o the rod and trimmed by a silicon carbide wheel to a size t h a t will permit i t to be inserted with ease into the mortar. T h e nut and rod are ground at the end until a flat pounding surface is attained.
VOL. 12, NO. 5
I
K AQUEOUS solution 2-aminoethanol (ethanolamine, monoethanolamine) can be identified readily by reacting with phthalic acid and confirming the melting point, 127" C., of the resulting 2-hydroxyethylphthalimide:
PROCEDURE. Mix equimolar proportions of phthalic acid and the 2-aminoethanol-for example, dissolve 0.166 gram of phthalic acid in hot water and add it to the aqueous solution containing 0.061 gram of 2-aminoethanol. The concentration of 2-aminoethanol in the sample must be assumed or be determined by some means such as titration with hydrochloric acid. One cubic centimeter of 1 N hydrochloric acid == 0.061 gram of 2-aminoethanol. E,va orate the solution to dryness and heat the residue at 210 for about 5 minutes. 2-Hydroxyethyl hthalimide (2) will be formed in quantitative yield. RecrystalEze from water, or, if inorganic impurities such as potassium chloride or sulfate are present, from an anhydrous solvent such as benzene or absolute alcohol. The resulting diamond-shaped plates melt at 127' C.
8.
Conversely, this reaction can be used for the identification of phthalic acid.
Identification by Oxalic Acid 2-Aminoethanol can also be identified in aqueous solution by reacting with oxalic acid and confirming the melting point, 199-200" C. uncorrected (correction, +3.8" C.), of the resulting salt formed by the oxalic acid and the amine [NHsCHyCH20H]: I n addition, this salt may be converted to N,N'-bis-(2hydroxyethy1)-oxamide, which has a melting point of 168' C. uncorrected (correction, $2.4" C.). CO-NHCHSCH~OH
I
CO-NHCH2CH20H Mix equimolar proportions of oxalic acid and 2PROCEDURE, aminoethanol-for example, dissolve 0,090 gram of oxalic acid in water and add it to the aqueous solution containing 0.061 gram of the 2-aminoethanol. Evaporate the solution to dryness and heat the residue at 110" C. for 5 minutes. Recrystallize from 70 per cent alcohol. The resulting elongated hexagonal plates melt with decomposition at 199-200' C., uncorrected. The salt is very soluble in water, and insoluble in absolute alcohol or glacial acetic acid. Analysis for CaHleOa?: calculated, N 13.20, oxalic acid 42.5; found, N 12.65, oxahc acid 44.0 per cent. If heated past the melting point to about 222' C., brisk boiling occurs with formation in good yield of N,N'-bis-(2-hydroxyethyl)-oxamide, melting point 168' C., uncorrected. This material, prepared in a different manner, has been previously described ( 1 ) . This reaction may also be used for the identification of oxalic acid.
Literature Cited Beilstein, 4th ed., Vol. IV, Main series, p. 285, Berlin, Julius Springer, 1922. (2) Wenker, J . A m . Chem. SOC.,59, 422 (1937).
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