%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES
%A Brienza, Monica
%A Duwig, Céline
%A Perez, S.
%A Chiron, Serge
%T 4-nitroso-sulfamethoxazole generation in soil under denitrifying conditions : field observations versus laboratory results
%D 2017
%L fdi:010070055
%G ENG
%J Journal of Hazardous Materials
%@ 0304-3894
%K Sulfamethoxazole ; Nitric oxide ; Soil ; Nitrosation ; Denitrification
%K BOLIVIE
%M ISI:000401375700021
%P 185-192
%R 10.1016/j.jhazmat.2017.04.015
%U https://www.documentation.ird.fr/hor/fdi:010070055
%> https://www.documentation.ird.fr/intranet/publi/2017/06/010070055.pdf
%V 334
%W Horizon (IRD)
%X The formation of 4-nitroso-sulfamethoxazole and 4-nitro-SMX, two transformation products (TPs) of sulfamethoxazole (SMX) was investigated under batch soil slurry experiments and in a field study. Due to their low occurrence levels (ng/L) in environmental waters, a suitable analytical method based on liquid chromatography - high resolution - mass spectrometry was developed. Consequently, field observations revealed, for the first time, the occurrence of 4-nitroso-SMX in groundwater at concentrations as high as 18 ng/L.Nitric oxide (NO center dot) steady-state concentrations were determined in soil slurry experiments because this reactive specie accounted for the formation of 4-nitroso-SMX and 4-nitro-SMX. Measurements revealed that environmental SMX concentrations (0.2-2 mu g/L) at neutral pH induced the accumulation of nitric oxide. Under acidic conditions (pH< 6), nitrous acid (HONO) was the major source of nitric oxide while under neutral/basic conditions nitric oxide release was related to the inhibition of denitrification processes. Under laboratory experiments, SMX nitration reaction appeared to be an irreversible transformation pathway, while 4-nitroso-SMX was slowly transformed over time. The occurrence of 4-nitroso-SMX conditions was therefore unexpected in the field study but could be due to its continuous input from soil and/or its relative persistence under anoxic conditions. A mechanism for 4-nitroso-SMX formation was proposed involving a nitrosative desamination pathway through a phenyl radical.
%$ 062 ; 038 ; 068 ; 021