Este estudo apresenta desenvolvimento, validação e aplicação de um método multirresíduo para determinação de nove agrotóxicos e um produto de degradação (α-endossulfam, β-endossulfam, α-HCH, g-HCH, aldrim, p,p'-DDE, p,p'-DDT, cipermetrina, deltametrina e trifluralina) em amostra de leite humano por dispersão em fase sólida e cromatografia gasosa com detector de captura de elétrons (GC/ECD). O método é considerado simples e eficiente, combinando a extração e a purificação em uma única etapa e quantificação por adição padrão para eliminar efeito de matriz. Os limites de detecção e quantificação do método variaram entre 0,002-0,079 mg mL-1 e 0,013-0,108 mg mL-1, respectivamente. O método proposto foi aplicado para a análise de 62 amostras de leite humano coletadas entre fevereiro e junho de 2010 em Lucas do Rio Verde-MT. p,p'-DDE (0,32-12,03 µg g-1 de gordura), p,p'-DDT (2,62-12,41 µg g-1 de gordura) e β-endossulfam (0,54-0,61 µg g-1 de gordura) foram quantificados em 29%, 5% e 3% das amostras analisadas, respectivamente. Aldrim foi encontrado abaixo do limite de quantificação do método em 7% das amostras. Embora esses compostos tenham sido encontrados nas amostras analisadas, as mães foram orientadas a continuar o aleitamento materno por ser considerado benéfico durante a infância.

This study presents the development, validation and application of a multiresidue analytical method intended to determine nine pesticides and a degradation product (α-endosulfan, β-endosulfan, α-HCH, g-HCH, aldrin, p,p'-DDE, p,p'-DDT, cypermethrin, deltamethrin, and trifluralin) in breast milk samples by solid-phase dispersion and gas chromatography with electron capture detector (GC/ECD). The proposed method is considered simple and efficient, combining extraction and clean up in a single step and quantification performed by standard addition to avoid the matrix effect. The method limits of detection and quantification varied between 0.002 and 0.079 µg mL-1 and 0.013 and 0.108 µg mL-1, respectively. The proposed method was applied to analyze 62 breast milk samples collected between February and June 2010 in Lucas do Rio Verde, Mato Grosso, Brazil. p,p'-DDE (0.32-12.03 µg g-1 of fat), p,p'-DDT (2.62-12.41 µg g-1 of fat) and β-endosulfan (0.54-0.61 µg g-1 of fat) were quantified in 29%, 5% and 3% of the samples, respectively. Aldrin was found below the method quantification limit in 7% of samples. Although these compounds were found in the analyzed samples, mothers were oriented to carry on feeding the infants as the breast milk is considered the optimum food during infancy.

A multiresidue method using HPLC/DAD for the determination of fourteen pesticides in water based on SPE, using SDVB (styrene divynilbenzene copolymer) as adsorbent was validated. Recoveries from 61 to 120%, relative standard deviation between 2 and 15% and detection limits from 0.07 to 0.75 µg L-1 were obtained. It was applied to 66 surface water samples collected in a degraded area at the headwaters of São Lourenço river, Mato Grosso, Brazil. Eight pesticides were detected in concentrations ranging from 0.15 to 35.25 µg L-1. Considering ecotoxicological data, carbendazim and carbofuran may represent a risk to aquatic organisms. These results draw attention to the contamination of this vulnerable degraded area.

Este estudo avaliou a dinâmica de pesticidas na cabeceira de drenagem do Rio São Lourenço, Mato Grosso, Brasil. Os pesticidas atrazina, flutriafol, metolacloro, α- e β-endosulfan e os metabólitos endosulfan sulfato, desetilatrazina e desisopropilatrazina foram determinados em amostras de água (superficial, subterrânea, de chuva e de escoamento superficial) e de sedimento (de escoamento superficial e de fundo) coletadas entre agosto de 2009 e julho de 2010 utilizando SPE-GC/MS-SIM (extração em fase sólida-cromatografia gasosa acoplada espectrometria de massas em modo de monitoramento seletivo de íons). Os resultados demonstraram que o escoamento superficial e a deposição atmosférica são processos importantes de entrada de pesticidas na água superficial, principalmente por pesticidas altamente adsorvidos nas partículas de sedimento, cuja concentração máxima foi de 2218 μg kg-1 para β-endosulfan, e dissolvidos em água com concentração máxima de 28,3 μg L-1 para atrazina. Endosulfan sulfato, atrazina e metolacloro foram os compostos detectados com maior frequência. A lixiviação foi uma via importante de transporte devido ao comportamento hídrico do solo e ao baixo nível do lençol freático, levando contaminação de águas subterrâneas bem como de águas superficiais devido ao fluxo em subsuperfície.

This study assessed the environmental dynamics of pesticides in the São Lourenço River headwaters, Mato Grosso State, Brazil. The pesticides atrazine, flutriafol, metolachlor, α- and β-endosulfan and the metabolites endosulfan sulfate, desethylatrazine and desisopropylatrazine were determined in water (rain, surface, ground and runoff) and in sediment (runoff and bottom) samples, collected from August 2009 to July 2010, by SPE-GC/MS-SIM (solid phase extraction-gas chromatography/mass detector with selected ion monitoring). Runoff and rain atmospheric deposition showed to be important pathways for surface water contamination mainly by highly sorbed pesticides found in sediment with maximum concentration of 2218 μg kg-1 for β-endosulfan, and in water with maximum concentration of 28.3 μg L-1 for atrazine. Endosulfan sulfate, atrazine and metolachlor were the compounds with the highest frequency of detection. Leaching was an important process of off-site transport mainly due to the hydric behavior of soil and the low depth of water table, leading to contamination of groundwater as well as surface water via subsurface flow.

Este estudo fornece dados sobre a presença dos pesticidas atrazina, clorpirifós, α-endossulfam, β-endossulfam, flutriafol, malatiom e metolacloro em água de áreas urbanas e rurais das cidades de Campo Verde e Lucas do Rio Verde, no estado do Mato Grosso, Brasil. Amostras de água superficial, de chuva e subterrânea foram coletadas nas estações de seca e chuva em 2007 e 2008 nessas importantes áreas produtoras de grãos. Os resultados revelaram maior diversidade de substâncias e frequência de detecção em amostras de água de chuva. Concentrações de atrazina, endossulfam e malatiom foram encontradas acima dos níveis permitidos pela legislação brasileira em algumas amostras de água superficial e subterrânea, e os metabólitos DIA (de-isopropil-atrazina) e endossulfam sulfato foram encontrados em níveis maiores do que os compostos parentais em algumas amostras. Nossos resultados demonstram a vulnerabilidade dos recursos hídricos nessas áreas e apontam para o risco de contaminação de áreas de nascentes de importantes córregos por pesticidas.

This study provides data on the presence of the pesticides atrazine, chlorpyrifos, α-endosulfan, β-endosulfan, flutriafol, malathion and metolachlor in water matrices in urban and rural areas of Campo Verde and Lucas do Rio Verde Cities, Mato Grosso State, Brazil. Surface, rain, and groundwater samples were collected in the rainy and dry seasons during 2007 and 2008 in these important grain-producing areas. The findings revealed a higher diversity of compounds and frequency of detection in the rain water than in surface and groundwater samples. Concentrations of atrazine, endosulfan and malathion above those permitted by Brazilian regulations were found in some surface and groundwater samples, and the degradation products DIA (deisopropylatrazine) and endosulfan sulfate, rather than their parental compounds, were found at higher levels in some samples. Our findings show the vulnerability of water systems in these areas and point to the risk of pesticide contamination in important headwater streams.

The influence of temperature (30 and 40 ºC) and soil humidity (20, 50 and 70% of water holding capacity) on the degradation of the herbicide diurom and the endosulfan metabolite, endosulfan sulfate was studied under laboratory conditions, in different soil layers (0-30, 30-38 and 38-83 cm) of an Oxisol (Yellow Latosol) collected in an agricultural area of Mato Grosso State, Brazil. Endosulfan sulfate was rapidly degraded under lower soil humidity, higher temperature and deeper soil layers. For diurom the opposite was observed as a consequence of its higher water solubility and lower soil sorption coefficient.

A discussion about groundwater contamination is presented in this work. Contamination by agricultural activity, more specifically by pesticides is emphasized. Indirect and direct estimates could be used to predict pesticide behavior in soil, and consequently, to evaluate the potential of groundwater contamination. These results could be applied to advise about the possibility of groundwater contamination by pesticides, and to provide subsidies for making decisions more quickly and efficiently.