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1.
Chemosphere ; 326: 138365, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36906004

RESUMO

The evaluation of contamination by domestic sewage is relevant in the Amazon region; however, it has neither been well-developed nor accompanied by research or monitoring programs. In this study, caffeine and coprostanol as indicators of sewage were investigated in water samples from Amazonian water bodies that crisscross the city of Manaus (Amazonas state, Brazil) and cover regions with distinct main land uses such as high-density residential, low-density residential, commercial, industrial, and environmental protection areas. Thirty-one water samples were studied based on their dissolved and particulate organic matter (DOM and POM) fractions. Quantitative determination of both caffeine and coprostanol was carried out using LC-MS/MS with APCI in the positive ionization mode. The streams of the urban area of Manaus had the highest concentrations of caffeine (1.47-69.65 µg L-1) and coprostanol (2.88-46.92 µg L-1). Samples from the peri-urban Tarumã-Açu stream and from the streams in the Adolpho Ducke Forest Reserve showed much lower concentrations of caffeine (20.20-165.78 ng L-1) and coprostanol (31.49-120.44 ng L-1). Samples from the Negro River showed a wider range of concentrations of caffeine (20.59-873.59 ng L-1) and coprostanol (31.72-706.46 ng L-1), with the highest values found in the outfalls of the urban streams. Levels of caffeine and coprostanol were significantly positively correlated in the different organic matter fractions. The coprostanol/(coprostanol + cholestanol) ratio proved to be a more suitable parameter than the coprostanol/cholesterol one in low-density residential areas. Proximity to densely populated areas and the flow of water bodies appear to influence the caffeine and coprostanol concentrations, which was observed in their clustering in the multivariate analysis. The results indicate that caffeine and coprostanol can be detected even in water bodies that receive very low domestic sewage input. Therefore, this study revealed that both caffeine in DOM and coprostanol in POM represent viable alternatives for use in studies and monitoring programs even in remote areas of the Amazon, where microbiological analyses are often unfeasible.


Assuntos
Colestanol , Poluentes Químicos da Água , Colestanol/análise , Esgotos/análise , Cafeína/análise , Cromatografia Líquida , Monitoramento Ambiental/métodos , Espectrometria de Massas em Tandem , Água/análise , Poluentes Químicos da Água/análise
2.
Environ Pollut ; 244: 818-826, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30390455

RESUMO

Sewage pollution is a principal factor of decreasing water quality, although it has not been considered a real impact in Amazonia that is still considered a pristine environment around the world. Thus, this study aimed to assess the levels of sewage contamination in sediments from three streams crossing Manaus - a Brazilian city of 2,403,796 inhabitants in the heart of the Amazon rain forest. Cholesterol, cholestanol, brassicasterol, ergosterol, stigmasterol, ß-sitosterol, campesterol, stigmastanol, coprostanol, and epicoprostanol levels were determined by liquid chromatography tandem mass spectrometry (LC-MS/MS). The fecal indicator, coprostanol, was found in high concentrations (509-12 830 ng g-1) and high relative proportions (21-54%) in all samples collected in the Mindu stream that crosses many heavily populated districts of the city, and in the Quarenta stream that crosses the Industrial District of Manaus. The sediments of the Tarumã-Açu stream also presented coprostanol; however, concentrations (

Assuntos
Monitoramento Ambiental/métodos , Rios/química , Esteróis/análise , Poluentes da Água/análise , Poluição da Água/análise , Qualidade da Água , Biomarcadores/análise , Brasil , Colestadienóis/análise , Colestanol/análise , Colestanóis/análise , Colesterol/análogos & derivados , Colesterol/análise , Cromatografia Líquida , Contaminação de Medicamentos , Fezes , Sedimentos Geológicos/química , Fitosteróis/análise , Esgotos/análise , Sitosteroides/análise , Espectrometria de Massas em Tandem
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