Use of the Spectrometric Sum Parameter for Aromatic Amines in the Monitoring of a Former Ammunition Plant

Abstract

Aromatic amines are important metabolites of nitroaromatic explosives, hence monitoring of aromatic amines' content at former ammunition plants is necessary. Twenty years ago, a threshold limit value of 0.1 μg/L for the sum of diazotizable aromatic amines in water distributed from the waterworks at the former ammunition plant in Stadtallendorf/Hesse was established. This value is still measured with a spectrometric sum parameter, in which diazotization and a subsequent azo coupling of the analytes are utilized. The sum parameter is well suited for the long-term monitoring of filter installations, and it allows very quick measurements and a non-target screening of aniline contents, both of which are important in research. Nevertheless as several problems are associated with this parameter, we developed analytical methods suitable for the determination of the most important single compounds contributing to the overall sum. Initial results of these methods show that amphoteric anilines are of considerable importance in ammunition waste but have been neglected up to now in official monitoring schemes. The summation of single compound contents in ammunition wastewater generally gives 3 to 6 times higher values than the spectrometrically determined sum, which is mainly due to the choice of the reference substance 4-nitroaniline in the sum parameter.