Micro-determination of acetaldehyde as its 2:4-dinitrophenylhydrazone

Abstract

A colorimetric method for the determination of acetaldehyde is described.Formation of the 2 : 4-dinitrophenylhydrazone in aqueous solution is followed by quantitative extraction into carbon tetrachloride. It has been found

The Radiolysis of Aqueous Methanol—Sodium Nitrate Solutions1

“…4 Hydrogen peroxide was determined by either the titanium sulfate6 and/or the iodide technique.6 Formaldehyde was quantitatively determined as its 2,4-dinitrophenylhydrazone according to the method described by Johnson and Scholes. 7 The red color which results after treatment with alkali was measured at 4300 A. on a Cary recording spectrophotometer (Model 14), which enabled the optical density of the solution to be determined at the time of mixing. Acetone wras estimated by the method developed by Berntsson.8 Gaseous products were collected by means of a Toepler pump after passing through two traps cooled to -78 and -196°, respectively.…”

Radiolytic Oxidation of Peptide Derivatives of Glycine in Aqueous Solution

“…The quantitative determinations of glyoxylic acid and formaldehyde were made after the methods of, Friedemann and HauiSen (8) and Johnson and Scholes (9) respecti vely ,wi th the modifications introduced by SOkol. 2…”

Reactions of hydroxyalkyl radicals with uracil

“…In the presence of oxygen no product is expected to be formed from eiq,,, and base degradation is achieved mainly through the reactions U+OH+UOH (12) UOH 3 products. is the concentration of alcohol and k,, and k, are the reaction rate constants for reactions (12) and (l), respectively. However, the hydroxyalkyl radicals might undergo reaction (4), as discussed, or undergo the reaction Thus, considering reactions (l), ( 4), RO + 0, -+ products.…”