Figure 6. UV spectral data for 4-ADNT product compared to glyoxal
and pyruvic aldehyde.
4 - Glyoxylic
4 - Pyruvic
4 - Derivative
4 - Pyruvalde
Figure 7. Quantitative determination of 2,4-dinitrophenylhydrazone derivatives of products from 2-ADNT
confirmed the generation of pyruvic acid as a stable end-product. Based on chromatographic re-
tention times, glycolic acid (HOCH2COOH) and acetic acid were also identified. Other acids ap-
peared in the profile, but their retention times could not be matched with authentic standards.
Oxalic acid eluted near the dead volume and was masked by the large amounts of nitrate ion
generated during ozonation. A comparison of acids generated from 2-ADNT and 4-ADNT is
shown in Figure 8 and indicates the direct difference in product compositions for identical ozona-
Using anion exchange with conductivity detection, nitrate ion could be resolved from oxalic
acid and other carboxylic acids. Formic, malonic, oxalic, and acetic acids were observed. The tenta-
tive identifications of acids observed by this technique are shown in Figure 9 for 2-ADNT and 4-
ADNT. The product profile was found not to agree with that observed on the Supelcogel column
(with UV detection), especially with respect to formic and pyruvic acids. These results indicate
that other methods of confirmatory analysis need to be addressed for the carboxylic acid fraction.