Occurrence of Parabens in Surface Water, Wastewater Treatment Plant in Southeast of Brazil and Assessment of Their Environmental Risk

Parabens are chemical compounds widely used that act as preservatives. Liquid-liquid extraction could be considered an efficient technique, as does not need special devices and is economically viable. Thus, the present research had the objective of developing and validating an analytical method for liquid-liquid extraction using fewer solvents and liquid chromatography coupled with diode array detector for the analysis of methyl, ethyl, propyl, and butylparaben in sanitary sewage samples from the São Carlos wastewater treatment plant before and after treatment; it was also accomplished in surface water samples from Santa Maria Madalena, Tijuco Preto, Gregório, and Monjolinho streams. To optimize the process conditions the factorial design was used to determine the most significant variables, through a central composite design. In addition, environmental risk analysis was performed to assess the risk of the paraben’s presence in surface waters for aquatic biota. The validation tests showed a good fit of the developed method. The methyl, ethyl, propyl, and butylparaben were detected in the range of μg L −1 , and ethyl and butylparaben were detected in every collected sample in a range of 0.38 to 11 μg L −1 . The species sensitivity distributions were calculated to assess the ecological risk of parabens, and the results showed a low risk for aquatic biota.