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An on-line solid phase extraction liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) method for the determination of 12 antimicrobials in sediment and surface water was developed and validated. Furthermore, the spatial and temporal antimicrobials distributions in the sediment and in the water of four fish farms located in the hydroelectric dam of Ilha Solteira Reservoir in Brazil were investigated over four seasons in three sampling sites: at the fish cages, 100 and 1,000 m downstream far from the cages. The method was performed using an Agilent Zorbax 80 SB-C8 column (9.4 × 15 mm, 5 µm) as the loading column, and the Agilent Zorbax Eclipse Plus C18 column (3.0 × 100 mm, 3.5 µm) as a separation column within a run time of 13 min. The limits of quantification were less than 9 ng·L(-1) for the antibiotics in water and 16 µg·kg(-1) in sediment; the recovery ranged from 80 to 119%, with a variation coefficient less than 11%, and the repeatability was lower than 15%. Oxytetracycline was found in the water in all sample seasons. However, florfenicol was identified in April and October 2013 and January 2014, and tetracycline was present in July 2013. Regarding the sediment, oxytetracycline and tetracycline were found in all sampling periods, but chlortetracycline was only identified in January 2014. The spatial distribution of antimicrobials showed that the main pollution source came from the fish farms. This study demonstrated that the proposed method is reliable for the monitoring of antimicrobials in water and sediments and it showed contamination in both matrices from Ilha Solteira Reservoir.

In recent years, pharmaceutical pollution in the environment has been a great concern due to the potential effects on the human and animal health. Some of the most used classes such as antibiotics, which are used to prevent and treat bacterial infections and promote the growth of livestock, deserve to be highlighted since their intensive use has contaminated environmental matrices such as soil, water, sediment, plants, and animals with effects on the biota. To better understand the potential ecological risk of antibiotics in environments and to develop management strategies for these substances searching to reach the reduction of these compounds in aquatic systems, one of the most important steps is to determine the environmental concentrations of these compounds in the environments through analytical methods and evaluate their effects on the biota. The goal of this chapter is contribute with information about the effects of these compounds on the biota as well as its environmental behavior and bacterial resistance in additional to the main techniques for samples preparation and quantitative and confirmatory methods for its determination in the environment.

Resumo -Os herbicidas são os produtos fitossanitários mais utilizados no mundo e indispensáveis para a produção de alimentos em larga escala. São compostos sintetizados para ação tóxica contra plantas, porém, os mesmos podem apresentar efeitos negativos a diversos outros organismos. Uma das formas de contato e/ou absorção da molécula pelo organismo em questão, é quando a mesma encontra-se em um corpo hídrico. Dessa forma, monitorar a perda e acúmulo de herbicidas em mananciais é procedimento indispensável para produção agrícola sustentável, especialmente no Brasil, principal consumidor de produtos fitossanitários do mundo e um dos maiores produtores de alimentos e detentor de corpos hídricos. Propõem-se com essa revisão apresentar fatores técnicos, operacionais, edafoclimáticos, físicos e químicos dos herbicidas e legislativos a respeito da contaminação de mananciais por herbicidas. Também são apresentados herbicidas detectados recentemente em corpos hídricos do Brasil e as principais técnicas para detecção e quantificação dos produtos na água. Em função da importância do Brasil no cenário mundial, com relação à produção de alimentos, os estudos relacionados ao monitoramento de herbicidas em mananciais são considerados insatisfatórios, principalmente com relação a países que têm a agricultura desenvolvida há mais tempo. Palavras-chaves: cromatografia, lixiviação, produtos fitossanitários, contaminação Abstract -Herbicides are the most important pesticides in the world and essential for food production. They are synthesized to affect plants but on the other hand can cause negative impact to non-target organisms in case of contamination of aquatic environments. Thus, monitor the loss of herbicides to aquatic environments is an indispensable assignment to practice a sustainable agriculture, especially in Brazil: the most important pesticide user in the world, one of the largest food producers and watershed holder. The purpose of the text is to present technical factors, operational, edaphoclimatic, physical and chemical of the herbicides and laws about water sources contamination by it. In addition, results of works that monitored herbicides in Brazilians water bodies and the main techniques for detection and quantification of these products also will be presented. Due to the importance of Brazil on the world stage, with respect to food production, studies related to the monitoring of herbicides in water sources should be developed more frequently, especially with respect to countries that have agriculture developed over time.