Hydrolysis of sulphonamides in aqueous solutions

• Hydrolysis is one of the most common reactions controlling abiotic degradation and is one of the main paths by which substances are degraded in the environment. Nevertheless, the available information on this process for many compounds, including sulphonamides (a group of antibiotic drugs widely used in veterinary medicine), is very limited. This is the first study investigating the hydrolytic stabilities of 12 sulphonamides, which were determined according to OECD guideline 111 (1st category reliability data on the basis of regulatory demands on data quality for the environmental risk assessment of pharmaceuticals). Hydrolysis behaviour was examined at pH values normally found in the environment. This was prefaced by a discussion of the acid-base properties of sulphonamides. All the sulphonamides tested were hydrolytically stable at pH 9.0, nine (apart from sulphadiazine, sulphachloropyridazine and sulphamethoxypyridazine) were stable in this respect at pH 7.0 and two (sulphadiazine and sulphaguanidine) at pH 4.0 (hydrolysis rate <= 10%; t(0.5(25 degrees c)) > 1 year). The degradation products were identified, indicating two independent mechanisms of this process. Our results show that under typical environmental conditions (pH and temperature) sulphonamides are hydrolytically stable with a long half-life; they thus contribute to the on-going assessment of their environmental fate. (C) 2012 Elsevier B.V. All rights reserved.

Ämnesord

NATURVETENSKAP  -- Annan naturvetenskap (hsv//swe)

NATURAL SCIENCES  -- Other Natural Sciences (hsv//eng)

Nyckelord

Sulphonamides

Hydrolysis

OECD 111 guideline

Kinetics

Degradation products

environmental risk-assessment

resistance genes

antibiotics

water

degradation

products

residues

soil

uliquen h

1992

marine ecology-progress series

v89

p93

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)