Studies on the possible formation of polychloroazobenzenes in quintozene treated soil

Treatment of different soils with quintozene at a level of 1000 parts/10⁶ and incubation for 24 days at 30 °C did not result in the formation of polychloroazobenzenes, although pentachloroaniline was formed. This negative finding is in line with previous work, where it was shown that azobenzenes can only be formed from substituted anilines with at least one free ortho position. Soil activity was demonstrated by incubation of 3,4-dichloroaniline under similar conditions yielding the expected 3,3′,4,4′-tetrachloroazobenzene. Mass fragmentography with a quadrupole mass spectrometer was used for the detection of polychloroazobenzenes. Mass spectra for the synthesised reference compounds are presented.