.
May, 1946
ANALYTICAL EDITION
335
DISCUSSION
Recoveries of known quantities of sulfur ill various forms by this method are compared with unoxidized recoveries in Table I. The accuracy has been found to be *0.2 mg. if the amount of sulfur present in the sample is between 3 and 20 mg. Compounds such as p-aminodimetli~ laniline sulfate, potassium aluminum sulfate, and hydrazine sulfate have been tried with similar success. Mi'xtures of organic and inorganic sulfur compoundh as found in paper-mill waste$ k n d themselves well to this method, providing all the material i n wqwnsion is first filtered out. The sulfur content of pyritc waters i'r~~iii cod-mining operations can be determined as simple sulfate,' with the reservation that iron in excem of 2 p.p.m. be removed from solution by precipitation. The iron, if not rcrnoved, oxidizes from ferrous t o ferric and results in a fine dark precipitate, the presence of which altcrs the sulfate values. ACKNOWLEDGMENT
The writ,er wishes to thank 11.M. Ellis, in charge of the Water Quality Laboratories, Columbia, Mo., for his assistance and for t,hc opport,unit,yto wri'te this paper. LITERATURE CITED (1) ('dlan, T.
Table I.
Compound
Recovery before Oxidation with Superoxol DifferTheory ence Mg. Mu. Mg.
Determined
2.62 NaHSOs 0.96 ?;azSzO3.~€1:C) 0.21 NazSz0c.2Hz0 1 . 4 7 XFiZQ203 10.01 NazS08
10.16 9.12 10.32 12.17 10.76
-7.54 -%I6 -10.11 -10.70 -0.75
Recovery after Oxidation with Superoxol Differmined Theory ence
DeterMg.
Mu.
My.
9,96 9.24 10.15 12.29 10.57
10.16 9.12
-0.20 f0.12 -0.17 +0.12 -0.10
10.32
12.17 10.76
( 7 ) Hoffman, W. Y . , ant1 Cardon. It., .1. Riol. ( ' h e m . , 109, 717 (8) (9) (10) (11) (12) (13) (14) (15) (16)
P., and Tuennies, G,,IND.Exo. CHEY..A N . \ I . .ED.
13, 461 (1941). (2) Chatron, M . , Bull. soc. chim. bid., 13, 300 (1931). (3) ('ope, C. L., Biochem. J . , 25, 1183 (1931). (4) Cutlibertson, D. P., and Thornpsett.S. L., I6id..25, 1337 (1931). (5) F:isk, C. H., J . B i d . Chem.. 47, 69 (1921). (6) b riedheim, Carl, and Nydegger, O t t o , Z.angezc. Chem., 20, 9-22 ( 1907).
Determination of Sulfur in Solutions Containing Known Amounts of Sulfur Compounds
(17) (18)
(1935). Hubbard, R.S.,I b i d . , 88, 663 (1930). Knorre, G. von, Chem. I n d . (Germany), 28, 2--13 (19UG). Lesure, A., and Dunee, A , Bull. soc. chim. biol., 10, 879 (1928). XIcKittrick, D. S., aiid Schmidt, C. I,. A . , A r r h . Riochem., 6 411 (1946). Muller, Wolf, Chem. Bw., 25, 1587 ( 1 9 0 2 , . On-en, E. C., Bidchem. J . , 30, 352 (1936). Pohorecka, B. L., Bull. soc. chim. biol.,9, 2ti3 (1927). Pollock, R. N., and Partansky, -4.XI., IND. ENG.(:HEM., ANAL. ED.,6 , 330 (1934). Pon-ers, M. H., and Rakefield, 12. G., Proc. S h f l Meeting#, M a y o Clinic, 6 , 401 (1931). Kaschig, F., 2.angew. Chem., 16 ( 2 6 ) ,617; 16 ( 3 4 ) , 818 (1903). Rkau, E. L., and Newell, I. L., IND.EKG.CHEM.,ANAT,.ED.,5, im- (1933). ~ Tomkins, S. S., Ibid., 14, 141 (1942). Wakefield, E. G., J . Biol. Chem., 81, 713 (1929). White, H. L., Am. J . Phvsiol., 65, 537 (1923). Yoshimatsu,S., Tokokic J . Esptl .Wed., 7, 553 (1926). > - - - - ,
(19)
(20) (21) (22)
Separation of 2,4-Dinitrophenylhydrazones by Chromatographic Adsorption JOHN D. ROBERTS'
AND
CHARLOTTE GREEN
Department of Chemistry, University of California
Lor Angeles, Calif.
IK
D E T E R M I K I S G the structure of a riuniber of unsaturated compounds by ozonization, considerable difficulty has been experienced in separating small amounts of low molecular weight carbonyl compounds. The most satisfactory method of isolation as these are readily is through t>he2,4-dinitrophenylhydrnzones, formed and are insoluble in vater, but in many cases separation of the derivatives by fractional crystallization is unsatisfactory. Separations of a number of 2,4-dinitrophenylhydrazonesby chromatographic adsorption have been reported by Strain ( 4 ) , by Lucae, Prater and Morris ( d ) , and by Buchman, Schlatter, and Reims ( I ) , but only a ferv of the aliphatic derivatives have been investigated. I n the present work, the adsorption of 2,4dinitrophenylhydrazine and the 2,4-dinitrophenylhydrazonesof acetaldehyde, propionaldehyde, acetone, and methyl ethyl ketone was studied on columns of silicic acid-Super Cel.
PROCEDURE. 'l'he dinitropheriylhydrazones (3) were adsorbed from solutions in 1 to 2 benzene-ligroin (60" t o 90"). The adsorbent was Merck's silicic acid (reagent grade) mixed R-ith Super Cel in a 2 to 1 ratio by weight t o increase the rate of flow of solvents through the column. The most satisfactor? .olvent for development of tht. chromatograms was ligroin (60 I Present address, Converse hlpiriorial Laboratory, Harvnrd University, ('atirbridge 38, >lass.
t,o 90") containing 4% ether by volume. Mixtures of benzene and ligroin gave more diffuse bands. After the column was extruded and sectioned, the derivatives were eluted with ether and crystallized from ethanol. I n a typical experiment a mixture of about 5 mg. each of acetone and met,hyl ethyl ketone 2,4-dinitrophenylhydrazones W L ~ B chromatographed on a 3.4 X 17 cm. column. After development the column consisted of the following bands: 4 cm. colorless, 4 cm. yellow, 2.5 cm. colorless, and 3.5 cm. yellow. The upper zone yielded the acetone derivative, m.p. 122-124.5" C. The lower band gave the methyl ethyl ketone deriva,tiva, m.p.
115" C. The 2,4-dinitrophenylhydrazuneswere lound to be adsorbed in the order: acetaldehyde, acetone, propionaldehyde, and methyl ethyl ketone. Each of these derivatives could -be separated from mixtures with the others and 2,4dinitrophenylhydrazine (strongly adsorbed) except for the hydrazone of acetone, which could not he separated from that of propionaldchgde. LITERATURE CITED
( I ) Buohmaii, Schlatter, and Reims, ..I. A m . (:hem. S o e . . 6 4 , 2701 (1942). (2) Lucas, Prater, and Morris, Ibid., 57, 725 (1935) (3) Roberts and Green, Ibid., 68, 214 (1946). (4) Strain, Ibid., 57, 758 (1935).
.
