Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / It is known that heavy use of pesticides, especially herbicides and insecticides, associated with the improper management of irrigation water can result in pesticide runoff out the crops to the waters streams, rivers or ponds, since the cultivation of rice is preferably done in areas that have large volumes of water available. Considering the importance of water for nature and human health, the low uncontaminated water resources available today and a large scale production of rice, this study aimed to develop and validate a method for the determination of pesticides in water from irrigated rice crop. Pesticides were extracted from samples of river water using the method of solid phase extraction (SPE). The simultaneous determination of selected pesticides in this study was made by a GC-(EI)-MS/MS. For each analyte, two MRM transitions were optimized, one for quantification and one for confirmation, as predicted by international guidelines and legislations. In the method validation the results were satisfactory for validation requirements, and the analytical curves of r² values are greater than 0.99. The value of the method LOQ for all compounds was established at 0.2 μg L-1. Recoveries for real water samples showed values between 70 and 120% with RSD values lower than 20% for most compounds studied. The results indicate that the proposed method for the analysis of 32 pesticides, including a step of SPE extraction and quantification by GC- (EI)-MS/MS is efficient and selective, allowing the quantification of low levels of concentration appropriate for monitoring these compounds in water. In addition, the validation parameters meet the minimum requirements for the validation of chromatographic methods, which enables the application of the method. Keywords: pesticides; water; GC-(EI)-MS/MS / O uso intensivo de agrotóxicos, especialmente herbicidas e inseticidas, associados ao manejo inadequado da água de irrigação pode resultar no escoamento destes compostos para os rios e lagoas. Ressalta-se que, o cultivo de arroz é feito preferencialmente em áreas que possuem grandes volumes de água disponíveis. Considerando-se a importância da água para a natureza e para a saúde humana, bem como, a escassez dos recursos hídricos e a produção em larga escala de arroz indispensável como alimento para a população, este estudo tem como objetivo desenvolver e validar um método para a determinação de 62 agrotóxicos em água de lavoura de arroz irrigado. Num primeiro momento, os analitos foram extraídos das amostras utilizando o método de extração em fase sólida (SPE) e a determinação simultânea dos agrotóxicos selecionados foi realizada por um GC-(EI) - MS/MS. Em seguida, para cada composto, duas transições MRM foram monitoradas: uma para quantificação e outra para confirmação, como o previsto pelas diretrizes internacionais e legislações. Em continuidade, na validação do método, os resultados foram satisfatórios para os requisitos exigidos, sendo que os valores de r² para as curvas analíticas foram maiores que 0,99. O valor do LOQ do método para todos os compostos foi estabelecido em 0,2 μg L-1. As recuperações apresentaram valores entre 70 e 120% com RSD inferior a 20% para a maioria dos compostos estudados. Finalmente, os resultados indicam que o método proposto para a análise de 32 agrotóxicos - incluindo uma etapa de extração e quantificação por SPE-GC- (EI) -MS/MS - é eficiente e seletiva, permitindo a quantificação de baixos níveis de concentração. Esses índices tornam a técnica adequada para o monitoramento destes compostos em água de lavoura de arroz irrigado. Além disso, os parâmetros de validação atendem aos requisitos mínimos para a validação de métodos cromatográficos, resultado que permitiu a aplicação do método desenvolvido e validado.

A method to detect nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) in the air has been developed using gas chromatography with an atmospheric pressure chemical ionisation source, coupled to a triple quadrupole mass spectrometer (GC-APCI-MS/MS). An attempt to create a GC method using negative chemical ionisation (NCI) and a high-resolution mass spectrometer, Orbitrap, (GC-NCI-MS) was made as well without success. Nitro-PAHs are a group of widespread contaminants considered as possible mutagens and carcinogens. They are formed from incomplete combustion of organic matter as well as secondary reactions between PAHs and nitrogen dioxide (NO2) in the air. Three air samples (outdoor, in an air vent and indoor), both particulate and gaseous phase, collected in central Örebro during the spring were extracted and analysed for nitro-PAHs on GC-APCI-MS/MS and for PAHs on GC-MS in EI (electron ionisation) mode. Several studies have reported lower amounts of nitro-PAHs than PAHs in the air, which can be seen in this report as well. The levels of detected nitro-PAHs (1-nitronaphalene and 9-nitroanthracene) and PAHs (naphthalene, anthracene, fluoranthene and pyrene) in the different samples were 10.2-119 pg/m3 and 291-77700 pg/m3, respectively. Neither group of analytes were found in the particulate phase. The highest concentrations of both nitro-PAHs and PAHs were found indoors, suggesting that other sources than emissions from traffic are responsible.