Determination of pesticides multiresidues in shallow groundwater in a cotton-growing region of Mato Grosso, Brazil

Abstract

Foi desenvolvido um método multirresíduos empregando CLAE/DAD para a determinação de doze pesticidas em águas subterrâneas em lavouras de algodão, baseado em extração em fase sólida, utilizado como adsorvente o copolímero estireno divinilbenzeno (SDVB). O método foi validado e obtiveram-se recuperações entre 73 e 113%, desvio padrão relativo entre 2 e 16% e limites de detecção variando de 0,06 a 0,57 µg L -1. O método foi aplicado em 110 amostras de águas subterrâneas de lavouras de algodão localizadas em Primavera do Leste, Mato Grosso, Brasil. Dos pesticidas analisados, oito (acetamiprido, aldicarbe, carbendazim, carbofurano, diurom, imidacloprido, metomil e teflubenzurom) foram detectados nas amostras de água, sendo que 18% continham pelo menos um dos pesticidas, com concentrações variando de 0,78 a 68,79 µg L -1 , excedendo em alguns casos, os níveis estabelecidos pela União Européia. Esses resultados confirmam a vulnerabilidade do lençol freático no que diz respeito à contaminação por pesticidas.Aiming to evaluate the contamination of groundwater by pesticides in cotton growing areas, an SPE-based method (styrene-divinylbenzene copolymer -SDVB) was developed for the simultaneous determination of twelve pesticides in water by HPLC/DAD. The method was validated and average recoveries ranged from 73 to 113%, with a relative standard deviation of 2 to 16%. Detection limits ranged from 0.06 to 0.57 µg L -1 . The method was applied to groundwater samples (110) from cotton fields located in "Primavera do Leste", Mato Grosso state, Brazil. Eight pesticides (acetamiprid, aldicarb, carbendazin, carbofuran, diuron, imidacloprid, methomyl and teflubenzuron) were found in the analyzed groundwater samples and 18% of them contained at least one of the pesticides (with concentrations ranging from 0.78 to 68.79 µg L -1 ). In some cases, detected concentrations exceeded the target levels set by the European Union. These findings confirm the vulnerability of shallow groundwater in the aforementioned areas to pesticide contamination.

Binary Solvent Dispersive Liquid-Liquid Microextraction for the Determination of Pesticides in Natural Water Samples

“…The limits of detection (LOD) and quantification (LOQ) were estimated by the ratio between the standard deviation of the intercept (s) and the slope of the analytical curves (S), being LOD equal to 3 times and LOQ to 10 times the s/S ratio. Low instrumental limits of detection (LOD i < 3.0 µg L -1 ) and quantification (LOQ i < 10.0 µg L -1 ) were achieved, similar to those described in the literature, [40][41][42][43] recalling that until then, no preconcentration step was performed. Furthermore, suitable linearity (r > 0.9997) was obtained in the studied LR for all compounds.…”

Biodegradation of the neonicotinoid insecticide acetamiprid in surface water by the bacterium Variovorax boronicumulans CGMCC 4969 and its enzymatic mechanism

“…For example, Leandro et al detected AAP in shallow groundwater in a cotton-growing region of Mato Grosso, Brazil. 7 Anderson et al reported AAP detection in the playa wetlands of Texas. 8 Wu et al detected AAP at a concentration of 0.2 mg L À1 in the Jingmi River, Beijing, China.…”

A comparison of predicted and measured pesticides concentrations in runoff of cotton farms in Brazil

“…Diuron residues in water was analysed according to the method described by Carbo et al (2008). Aliquots of 500 ml of the samples were extracted in a SDVB cartridge (Envi-Chrom P, Supelco) previously conditioned with methanol.…”

“…regions with cotton industry several pesticides have been detected in surface water and among the innumerous factors that affect pesticides runoff, the agricultural management system is a very important one (Carbo et al, 2008).…”

“…Moreover, many studies point out that there is high risk of the environmental contamination of some pesticides, such as, α and β-endosulfan, diuron and metolachlor (Weaver et al, 2012;Kennedy et al, 2001; Barrett and Jaward, 2012). In addition, literature indicates that in tropical regions with cotton industry several pesticides have been detected in surface water and among the innumerous factors that affect pesticides runoff, the agricultural management system is a very important one (Carbo et al, 2008;Casara et al, 2012). Hence, it is necessary to study the influence of the management systems in the dynamics of the pesticides in the environment The present study, therefore, aimed to adjust a model by combination of the pesticide concentration model, reported by OECD (1999), with Runoff Curve Number (RCN) developed by the USDA Natural Resources Conservation Service (SCS-USDA), and the water balance in soil surface (WB) describe by Pruski et al (1997) to estimate the concentrations of α-and βendosulfan, diuron and metolachlor in runoff.…”