US EPA

1812854 

Journal Article 

Determination of Formaldehyde Using a Kinetic-Spectrophotometric Method. Part II: Oxidation of N-Methyl-Substituted-1,4-phenylenediamines with Hydrogen Peroxide 

Evmiridis, NP; Sadiris, NC; Karayannis, MI 

1990 

1 

Analyst
ISSN: 0003-2654
EISSN: 1364-5528 

NIOSH/00196999 

115 

8 

1103-1107 

10.1039/an9901501103 

WOS:A1990DW68500018 

The catalytic effect of formaldehyde (50000) in the oxidation of N-methyl substituted p-phenylenediamines was presented. This catalytic effect was compared with that of p-phenylenediamine and was followed by changes in pH, concentration of reagent, oxidant, formaldehyde, and temperature. Finally, a more sensitive method for formaldehyde determination was proposed using N,N-dimethyl-1,4-phenylenediamine as reagent. As a result of comparing the N,N-dimethylphenylenediamine method with that of p-phenylenediamine, the authors concluded that at optimum conditions the sensitivity of the method is about 1.3 times higher; the interference from the formation of the Bandrowski Base is much lower; the detection limit, although lower, is still in the range of a few parts per million; and the other analytical parameters such as selectivity, valid range of calibration graph, and interference from other reductants or oxidants involved in atmospheric air, are the same. This investigation indicates that by slightly increasing the stability of the transient quinone-diimine products of the formaldehyde catalyzed oxidation reaction of the p-phenylenediamine derivatives, a considerable increase in the sensitivity of the method is obtained. The authors therefore suggest that compounds that form quinone-diimine products of high stability during similar oxidations can increase the sensitivity of the method to a level such that the detection limit reaches the parts per billion range. 

DCN-192434; Analytical methods; Chemical analysis; Analytical chemistry; Aldehydes; Diamines; Absorption spectrophotometry; Reagents; Oxidation reduction reactions