Development and validation of methodology SPE-LC-MS/MS for pharmaceuticals and illicit drug determination in the waters of Guarapiranga Dam, Sao Paulo, SP, Brazil

This study presents the development of the methodology of solid phase extraction and liquid chromatography - tandem mass spectrometry, SPE-LC-MS/MS, for the determination of 21 (twenty one) pharmaceuticals belonging to different therapeutic groups, 1 (one) illicit drug and its major metabolite, in surface water samples. The chromatographic separation was optimized by studying the performance of different stationary and mobile phases. Quantitation of selected compounds was performed by electrospray ionization (ESI) and the mass spectrometer operating in a multiple reaction monitoring (MRM) mode. The validation of the proposed methodology was performed using the parameters of selectivity, matrix effect, dynamic range, linearity, limit of detection (LOD), limit of quantification (LOQ), precision, accuracy, recovery and robustness. The validation of methodology allowed to apply the methodology in the evaluation of the distribution of the 23 (twenty one) selected compounds, in Guarapiranga Dam waters, an of the major producer system of drinking water of the Metropolitan Region of Sao Paulo (MRSP). The presence of these pollutants in aquatic environments is from the direct release of urban sewage from the homes of your surroundings, as a result of poor sanitation system. The waters of Guarapiranga dam were evaluated in 14 (fourteen) locations strategically chosen and sampled in 3 (three) campaigns of sample collection (August 2011, September 2012 and April 2013). In these samples were quantified acetaminophen (9.6 - 254 ng L^-1), atenolol (8.5 - 177 ng L^-1), benzoylecgonine (7.9 - 139 ng L^-1), caffeine (27 - 27386 ng L^-1) carbamazepine (12 - 358 ng L^-1), chlorthalidone (9.4 - 35 ng L^-1), cocaine (12.8 - 2560 ng L^-1), diclofenac (8 - 36 ng L^-1), enalapril (20 ng L^-1), losartan (6.7 - 114 ng L^-1) and valsartan (9.7 - 47 ng L^-1). The sample siting GU103-12 (23°41'88.5”S 46°44'67.3”W) was the region with the highest values in the level of concentration of the target compounds and the integrated risk index of chemical aquatic pollution (IRICAP). The study was also conducted on water samples from reservoirs of the UGRHI (Unit of Water Resources Management) 5 and 6, State o São Paulo. The results showed that the use and occupation of land directly influence the reservoir water quality highlighting the need to implement improvements in sewage collection system and illegal occupation to prevent contamination and the improper disposal in aquatic environments. (author)