lower concentration, accuracy is substantially improved. Reduction Process. AI cister and Major (8) have shown the amount of ring or chain form of a number of aldohexose hydrazones. B y varying the mercury column height on the hydrazones which they report, kinetic currents were found in cases of ring structure and mixed kinetic and diffusion currents in situations where both ring and chain forms were found. The hydrazones of the aldopentoses seem t o exist primarily in a nonreducible form in equilibrium with only a minute amount of the reducible chain form. During the reduction of the reducible form, equilibrium is disturbed a t the dropping electrode and new reducible form is produced. The height of the wave is thus a function of the rate constant for the kinetic process:
hydrazone(ringform)
LITERATURE CITED
+
hydrazone(chainform). This concept parallels the conclusions of Wiesner (10) and Delahay and Strassner (5) on the sugars themselves. The ease of transformation of the cyclic hydrazone based on relative wave heights a t the same concentration of sugar is similar to the ease of transformation found by Delahay and Strassner ( 3 ) and Cantor and Peniston (2) for the cyclic form of the sugar to the open aldehyde form. The results of Cantor and Peniston have to be reinterpreted according to the concept of kinetic currents. The reduction process is probably the addition of 2 hydrogen ions to the C=N- bond, a two-electron process.
,4dams, €1. N., Reilley, C. N., Furman, IT. H., ANAL. CHEW 24, 1200 (1952). Cantor, 1,. bl.,Peniston, Q. bl., J . Am. Clrem. SOC.62, 213 (1940). Delahay, P., Strassner, J. E., Ibid., 74, 893 (1952). Dlezelr, J., Xbornik dlezinbrod. Polarag. Sjezdu Prme, 1st Congr. 1951, €It. 1, 740. DomansltJf, R., Ibid., p. 730. Lingane, J. J., Laitinen, H. A., IND. ESG. (>HEM., ANAL. E D . 11, 504 (1939). Lupton, J. AI., Lynch, C. C., J . Am. Chem. SOC.66, 697 (1944). hIeister. L.. Maior. " , A.., Ibid.. 77. I
.
4297(1996).
WhitnacE:, G. C., Young, J. E., Sisler, H. H., Gantz, E. S., AXAL. CHEX 28, 833 (1956). Wiesner, I
