Multiresidue determination of herbicides in environmental waters from Primavera do Leste Region (Middle West of Brazil) by SPE-GC-NPD

Abstract

Foi desenvolvido um estudo sobre a presença dos herbicidas simazina, metribuzim, metolacloro, trifluralina, atrazina e seus metabólitos desisopropilatrazina (DIA) e desetilatrazina (DEA) em água superficial e subterrânea da região de Primavera do Leste, Mato Grosso, Brasil. O procedimento analítico baseou-se na extração em fase sólida com cartuchos descartáveis Sep-Pak C 18 e eluição com acetato de etila. Os níveis de resíduos foram determinados por cromatografia a gás com detector de nitrogênio e fósforo. Para a maior parte dos pesticidas, a recuperação média nos diferentes níveis de fortificação foi >70% com estimativa do desvio padrão relativo <19%. As recuperações observadas para o DIA e a trifluralina foram 25% e 56%, respectivamente. As baixas recuperações foram atribuídas à retenção incompleta do DIA e à forte retenção no sorvente e alta volatilidade da trifluralina. Os limites de detecção variaram de 0,023 a 0,088 μg L -1 . Este método foi aplicado na análise de 5 amostras de águas superficiais e 28 de águas subterrâneas, em pontos usados para abastecimento de água para consumo humano, coletadas em Primavera do Leste, Mato Grosso. O nível mais elevado encontrado nas amostras de água foi 1,732 μg L -1 de metolacloro enquanto o herbicida encontrado com maior freqüência foi o metribuzim.A study on the presence of herbicides, namely simazine, metribuzin, metolachlor, trifluralin, atrazine and two metabolites, deisopropylatrazine (DIA) and deethylatrazine (DEA), was performed in ground and surface waters from Primavera do Leste region, Mato Grosso state (Middle West of Brazil). The analytical procedure was based on solid-phase extraction (SPE) with Sep-Pak C 18 disposable cartridges and ethyl acetate for elution solvent. Residue levels were determined by gas chromatography with nitrogen-phosphorus detection. For most of the pesticides average recoveries at different fortification levels were >70% with relative standard deviation <19%. The recoveries of DIA and trifluralin in water were 25% and 56%, respectively, which were attributed to the incomplete retention of DIA and strong retention on the sorbing material and high volatility of trifluralin. Detection limits ranged from 0.023 to 0.088 μg L -1 . This method was applied for the analysis of 5 superficial water samples and 28 groundwater samples, in places used for human consumption without previous treatment, collected in Primavera do Leste, Mato Grosso, Brazil. Results indicated that the highest level of contamination in a water sample was 1.732 μg L -1 for metolachlor, while metribuzin was the most frequently detected herbicide with maximum concentration of 0.351 μg L -1 .Keywords: solid-phase extraction, water, herbicides, pesticides, GC-NPD IntroductionThe Primavera do Leste region (Mato Grosso state, Middle West of Brazil) is an area with a high agricultural production, that has expanded greatly since its start 30 years ago. As consequence of the monoculture conditions under which soybean, cotton, rice, maize and bean are grown, they are susceptible t...

The Effects of Subchronic Exposure to Metribuzin onDanio rerio

“…In a study of the presence of herbicides in Brazil, metribuzin was the most frequently detected herbicide (with a maximum concentration of 0.351  μ g L −1 [9]). Metribuzin is highly toxic to freshwater macrophytes and algae [10].…”

Effect of the Presence of Nonionic Surfactant Brij35 on the Mobility of Metribuzin in Soil

“…Consequently, it may have the potential to leach into the soil profile and thus contaminate groundwater. Further, metribuzin was detected at the highest concentration of 25 μg L −1 in Lack Erie tributaries [26] and found to be the most frequently detected herbicide with a maximum concentration of 0.351 μg L −1 in 20 samples from drinking water wells in Brazil [27]. The half-life of metribuzin in soils ranges from 11 to 46 days in lab and field experiments; however, it was reported to be as long as 60-90 days under winter conditions in Manitoba [28].…”

Dynamics of diuron and sulfentrazone formulations in soils with different textures

“…The current agricultural systems depend on the use of herbicides for control of weedy species and reduce possible interferences of these species on the crop development and yield, as in the case of sugarcane crops. However, concerns about the environment fate and risk of contaminations have Planta Daninha 2020;38:e020221524 -https://doi.org/10.1590/S0100-83582020380100068 2/8 emerged, since several molecules applied in this crop were found in surface water and groundwater (Dores et al, 2006;Gomes et al, 2006;Britto et al, 2012).…”