V O L U M E 20, NO. 10, O C T O B E R 1 9 4 8 lem could be solved by reducing the heating time to the point wyhere the slon-er reacting monosaccharides are negative while the faster reacting monoqaccharides are positive. Finally, by heating a nii\tuie of sugars for various durations of time and measuring the subsequent color developed, binary and ternary mixtures of sugars might poqsiblv be determined by mathematical analv-is of the results obtained. LITERATURE CITED
(1) Bron-n, C. A,, and Zerban, F. W., “Physical and Chemical Methods of Sugar Analysis,” p. 651, Kew York, John Wile,- & Sons,
1941.
93s (2) Dorfmtiller, G., Deut. Zuckerind., 44, 574 (1919) , (3) Gilbert, S. G., U. S. Dept. Agr., Bur. Plant Industry, soil3 and
(4) (5) (6) (7) (8)
Agricultural Engineering, private communication to Leslie R. Hedrick, Illinois Institute of Technology, October 1946. Heard, R. D. H., and Sobel, H., J . Biol. Chem.. 165, 687 (1946). Lo, C., and Chu, L. J., IXD.ESG. CHEM.,-&SAL. ED., 16, 637 (1944). Matthem, N. W., Maryland Acad. Sci., Bull. 7, No. 3, 35 (1928). Pinoff, E., and Gude, K., Chem. Z t g . , 38, 625, 626 (1914). Woods, J. T., with Mellon, AT. G., ISD.ENG.CHEST., AKAL.ED., 13, 760 (1941).
RECEIVED February 9, 1948. Presented before the Division of Analytica and Micro Chemistry a t the 113th Meeting of the AXERICINCHEMICAL S O C I E I P , Chicago, 111.
Determination of Tetraethyl Pyrophosphate in Mixtures of Ethyl Phosphate Esters AT. N. DVORNIKOFF AND H. I,. l\JOKRTLL, Monsanto Chemical Company, S t . Louis, M o .
An analytical method f o r determining tetraethyl pyrophosphate in mixtures of ethyl phosphate esters involves selective hydrolysis of the higher polyphosphates and separation of tetraethyl pyrophosphate, triethyl phosphate, and a small amount of diethyl acid phosphate by benzene extraction. The diethyl ester is neutralized and the tetraethyl pyrophosphate is determined by hydrolysis with alkali, Trieth?1 phosphate does not interfere.
T
HE principal insecticidally active ingredient in mixtures of ethyl phosphates such as “hexaethyl tetraphosphate,”
technical tetraethyl pyrophosphate, etc., is generally recognized to be tetraethyl pyrophosphate:
(
