Distribution of organochlorine, organophosphates, carbamate, thiocarbamate, pyrethroids, and strobilurins in surface sediments of the Rio de Ondas watershed by GC-MS

• Published in: Journal of environmental science and health. Part B, Pesticides, food contaminants, and agricultural wastes Pesticides, food contaminants, and agricultural wastes, 2021, Vol.56 (4), p.357-369
• Main Authors: Lima do Rêgo, Enoc, Santos da Silva, José Domingos, Costa Nakamura, Thamilin, Diniz, Paulo Henrique Gonçalves Dias, Oliveira, Uldérico Rios, Souza, Jurandir Rodrigues de
• Format: Article
• Language: English
• Subjects: Carbofuran; Dimethoate; Gas chromatography; Insecticides; Legislation; Malathion; Mass spectrometry; Mass spectroscopy; Organic compounds; Organochlorine pesticides; Organophosphates; Pesticide residues; Pesticides; Pyrethroids; Sediment samplers; Sediments; solid-liquid extraction; Water analysis; Water circulation; Water column; water contamination; Water quality
• ISSN: 0360-1234; 1532-4109
• DOI: 10.1080/03601234.2021.1885263

The determination of some pesticides in surface sediments can provide important information about their distribution in the water column. This work aimed to determine the distribution of the classes of pesticides along the Ondas River's hydrographic basin (ORHB), in eighteen different points, during the dry and rainy periods. The pesticides were extracted from the sediment samples by solid-liquid extraction and then analyzed using a gas chromatograph coupled to mass spectrometry. After the development and validation of the method, nineteen pesticides from the group of organochlorine, organophosphates, carbamate and thiocarbamate, pyrethroids, and strobilurins were quantified in at least one point in the two collection periods, with accuracy varying between 86 and 126%. The average concentrations were 0.020 ng g −1 (carbofuran) to 249.123 ng g −1 (dimethoate) and 0.029 ng g −1 (carbofuran and sulfotep) to 533.522 ng g −1 in the dry and rainy periods, respectively. The results showed a wide distribution of pesticide residues in the ORHB, with higher levels for dimethoate, phenitrothion, and malathion, which may be related to their agricultural use in the region. In Brazil, it does not have specific legislation for maximum permitted values of pesticides in sediment, allowing for inappropriate or prohibited use and, consequently, affecting water quality.