engleski

IDENTIFICATION OF SULFONAMIDES PHOTODEGRADATION PRODUCTS IN DIFFERENT WATER MATRICES

Today it is well established that the source, presence and the fate of pharmaceutical active compounds in the environment is of concern. This area of research has progressively received more attention as many pharmaceuticals in surface water becomes evident. Once released into the aquatic environment, pharmaceuticals may undergo different degradation processes. Photodegradation, for example, might be an important elimination process for light-sensitive pharmaceuticals, such as antibiotics. It takes place mainly in surface water, while it may not occur when the compounds are present in turbid water, if the creek, river or lake is shadowed by trees, or if the compounds are in soil, sewage, and sewage pipes since they have low light exposure. The effectiveness of photodegradation depends on light intensity and frequency, pH and hardness of the water, and type of matrix and location, and it also varies with season and latitude. Sulfonamides represent one of the commonly used families of antibiotics in veterinary medicine, although they were frequently applied as human medicines to treat many kinds of infection. Since they have aromatic rings, heteroatoms, and other functional chromophore groups that can absorb solar radiation, photodegradation can be promising process for their elimination. To investigate the appearance of photodegradation products, three sulfonamides (sulfadiazine, sulfamethazine, sulfamethoxazole) were irradiated under simulated sunlight in three different water matrices (MilliQ water, natural water and synthetic wastewater similar by composition to wastewater of pharmaceutical industry). Irradiated solutions were analyzed by LC-MS/MS, which was performed with an Agilent 6410 triple-quadrupole mass spectrometer coupled with an Agilent Series 1200 HPLC system. Except the structures of sulfonamides photodegradation products which were suggested on the basis of mass spectra, photodegradation kinetics of selected sulfonamides was also investigated.

sulfonamides; photodegradation pathways; water matrices

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