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

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 C18 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 >with relative standard deviation < 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 ��g 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 ��g L-1 for metolachlor, while metribuzin was the most frequently detected herbicide with maximum concentration of 0.351 ��g L-1. ��2006 Sociedade Brasileira de Qu��mica.

Cortisol response to acute stress in jundi�� Rhamdia quelen acutely exposed to sub-lethal concentrations of agrichemicals

Exposure to agrichemicals can have deleterious effects on fish, such as disruption of the hypothalamus-pituitary-inter-renal axis (HPI) that could impair the ability of fish to respond to stressors. In this study, fingerlings of the teleost jundi�� (Rhamdia quelen) were used to investigate the effects of the commonly used agrichemicals on the fish response to stress. Five common agrichemicals were tested: the fungicide - tebuconazole, the insecticide - methyl-parathion, and the herbicides - atrazine, atrazine + simazine, and glyphosate. Control fishes were not exposed to agrichemicals and standard stressors. In treatments 2-4, the fishes were exposed to sub-lethal concentrations (16.6%, 33.3%, and 50% of the LC50) of each agrichemical for 96��h, and at the end of this period, were subjected to an acute stress-handling stimulus by chasing them with a pen net. In treatments 5-7 (16.6%, 33.3%, and 50% of the LC50), the fishes were exposed to the same concentrations of the agrichemicals without stress stimulus. Treatment 8 consisted of jundi��s not exposed to agrichemicals, but was subjected to an acute stress-handling stimulus. Jundi��s exposed to methyl-parathion, atrazine + simazine, and glyphosate presented a decreased capacity in exhibiting an adequate response to cope with stress and in maintaining the homeostasis, with cortisol level lower than that in the control fish (P < 0.01). In conclusion, the results of this study clearly demonstrate that the acute exposure to sub-lethal concentrations of methyl-parathion, atrazine + simazine, and glyphosate exert a deleterious effect on the cortisol response to an additional acute stressor in the jundi�� fingerlings. �� 2008 Elsevier Inc. All rights reserved.

Resposta cortisol��mica e sensibilidade ao horm��nio adrenocorticotr��fico (ACTH) de jundi�� (Rhamdia quelen) em exposi����o sub-letal a agrot��xicos

Conselho Nacional de Desenvolvimento Cient��fico e Tecnol��gico (CNPq)

Contamina����o de ��guas superficiais e subterr��neas por pesticidas em Primavera do Leste, Mato Grosso

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

Ecotoxicological Evaluation of Poly(epsilon-Caprolactone) Nanocapsules Containing Triazine Herbicides

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Preparo e caracteriza����o de nanopart��culas lip��dicas s��lidas como sistema carreador conjunto para os herbicidas atrazina e simazina visando futuras aplica����es em agricultura

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Iron(III) Porphyrin Covalently Supported onto Magnetic Amino-Functionalized Nanospheres as Catalyst for Hydrocarbon and Herbicide Oxidations

This work describes the covalent immobilization of an ironporphyrin, 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin iron(III) chloride (FeTFPP), onto maghemite/silica magnetic nanospheres covered with aminofunctionalized silica. The resulting material (gamma-Fe2O3/SiO2-NHFeP) was characterized by diffuse reflectance infrared spectroscopy (DRIFTS) and UV-Vis absorption spectroscopy. The catalytic activity of this magnetic ironporphyrin was investigated in the oxidation of hydrocarbons (styrene, (Z)-cyclooctene and R-(+)-limonene) and an herbicide (simazine) by hydrogen peroxide or 3-chloroperoxybenzoic acid. Hydrocarbon and simazine oxidation reaction products were analyzed by gas chromatography (GC) and high performance liquid chromatography (HPLC), respectively. This catalytic system proved to be efficient and selective for hydrocarbon oxidation, leading to high product yields from styrene (89%), cyclooctene (71%) and R-(+) -limonene (86%). Simazine oxidation was attained with 100% selectivity for a dechlorinated product (OEAT), while several oxidation products were obtained for the same catalyst in homogeneous media. The catalyst can be easily recovered through application of an external magnetic field and washed after reaction. Catalyst reuse experiments for R-(+)-limonene oxidation have shown that the catalytic activity is kept at 90% after 10 consecutive reactions.

Iron(III) porphyrin covalently supported onto magnetic amino-functionalized nanospheres as catalyst for hydrocarbon and herbicide oxidations

This work describes the covalent immobilization of an ironporphyrin, 5,10,15,20- tetrakis(pentafluorophenyl)porphyrin iron(III) chloride (FeTFPP), onto maghemite/silica magnetic nanospheres covered with aminofunctionalized silica. The resulting material (&#947;-Fe2O3/SiO2-NHFeP) was characterized by diffuse reflectance infrared spectroscopy (DRIFTS) and UV-Vis absorption spectroscopy. The catalytic activity of this magnetic ironporphyrin was investigated in the oxidation of hydrocarbons (styrene, (Z)-cyclooctene and R-(+)-limonene) and an herbicide (simazine) by hydrogen peroxide or 3-chloroperoxybenzoic acid. Hydrocarbon and simazine oxidation reaction products were analyzed by gas chromatography (GC) and high performance liquid chromatography (HPLC), respectively. This catalytic system proved to be efficient and selective for hydrocarbon oxidation, leading to high product yields from styrene (89%), cyclooctene (71%) and R-(+)-limonene (86%). Simazine oxidation was attained with 100% selectivity for a dechlorinated product (OEAT), while several oxidation products were obtained for the same catalyst in homogeneous media. The catalyst can be easily recovered through application of an external magnetic field and washed after reaction. Catalyst reuse experiments for R-(+)-limonene oxidation have shown that the catalytic activity is kept at 90% after 10 consecutive reactions.

Desenvolvimento e avalia����o de m��todos de extra����o e separa����o cromatogr��fica em colunas monol��ticas e superficialmente porosas para determina����o de herbicidas triaz��nicos em solos e ��guas

O uso de pesticidas levou ao aumento da produtividade e qualidade dos produtos agr��colas, por��m o seu uso acarreta na intoxica����o dos seres vivos pela ingest��o gradativa de seus res��duos que contaminam o solo, a ��gua e os alimentos. Dessa forma, h�� a necessidade do monitoramento constante de suas concentra����es nos compartimentos ambientais. Para isto, busca-se o desenvolvimento de m��todos de extra����o e enriquecimento de forma r��pida, com baixo custo, gerando um baixo volume de res��duos, contribuindo com a qu��mica verde. Dentre estes m��todos destacam-se a extra����o por banho de ultrassom e a extra����o por ponto nuvem. Ap��s o procedimento de extra����o, o extrato obtido pode ser analisado por t��cnicas de Cromatografia a L��quido de Alta Efici��ncia (HPLC) e a Cromatografia por Inje����o Sequencial (SIC), empregando fases estacion��rias modernas, tais como as monol��ticas e as part��culas superficialmente porosas. O emprego de SIC com coluna monol��tica (C18, 50 x 4,6 mm) e empacotada com part��culas superficialmente porosas (C18, 30 x 4,6 mm, tamanho de part��cula 2,7 ��m) foi estudado para separa����o de simazina (SIM) e atrazina (ATR), e seus metab��litos, desetilatrazina (DEA), desisopropilatrazina (DIA) e hidroxiatrazina (HAT). A separa����o foi obtida por elui����o passo-a-passo, com fases m��veis compostas de acetonitrila (ACN) e tamp��o Acetato de Am��nio/��cido ac��tico (NH4Ac/HAc) 2,5 mM pH 4,2. A separa����o na coluna monol��tica foi realizada com duas fases m��veis: MP1= 15:85 (v v-1) ACN:NH4Ac/HAc e MP2= 35:65 (v v-1) ACN:NH4Ac/HAc a uma vaz��o de 35 ��L s-1. A separa����o na coluna com part��culas superficialmente porosas foi efetivada com as fases m��veis MP1= 13:87 (v v-1) ACN: NH4Ac/HAc e MP2= 35:65 (v v-1) ACN:NH4Ac/HAc �� vaz��o de 8 ��L s-1. A extra����o por banho de ultrassom em solo fortificado com os herbicidas (100 e 1000 ��g kg-1) resultou em recupera����es entre 42 e 160%. A separa����o de DEA, DIA, HAT, SIM e ATR empregando HPLC foi obtida por um gradiente linear de 13 a 35% para a coluna monol��tica e de 10 a 35% ACN na coluna com part��culas superficialmente porosas, sendo a fase aquosa constitu��da por tamp��o NH4Ac/HAc 2,5 mM pH 4,2. Em ambas as colunas a vaz��o foi de 1,5 mL min-1 e o tempo de an��lise 15 min. A extra����o por banho de ultrassom das amostras de solo com presen��a de ATR, fortificadas com concentra����es de 250 a 1000 ��g kg-1, proporcionou recupera����es entre 40 e 86%. A presen��a de ATR foi confirmada por espectrometria de massas. Foram realizados estudos de fortifica����o com ATR e SIM em amostras de ��gua empregando a extra����o por ponto nuvem com o surfactante Triton-X114. A separa����o empregando HPLC foi obtida por um gradiente linear de 13 a 90% de ACN para a coluna monol��tica e de 10 a 90% de ACN para a coluna empacotada, sempre em tamp��o NH4Ac/HAc 2,5 mM pH 4,2. Em ambas as colunas a vaz��o foi de 1,5 mL min-1 e o tempo de an��lise 16 min. Fortifica����es entre 1 e 50 ��g L-1 resultaram em recupera����es entre 65 e 132%.

Phototoxicity of photosystem II (PSII) herbicides to coral

Recent reports of contamination of the Great Barrier Reef Marine Park by herbicides used in antifouling paints and in agriculture have caused concern over the possible effects on corals in nearshore areas. Pulse-Amplitude Modulated (PAM) chlorophyll fluorescence techniques were used to examine changes in the maximum effective quantum yield (��F/Fm���) of symbiotic dinoflagellates within the host tissues (in hospite) of the coral Seriatopora hystrix exposed to a number of Photosystem II (PSII) inhibiting herbicides in short-term toxicity tests. The concentration of herbicide required to reduce ��F/Fm��� by 50% (median effective concentration [EC50]) differed by over 2 orders of magnitude: Irgarol 1051 (0.7 ��g l-1) > ametryn (1.7 ��g l-1) > diuron (2.3 ��g l-1) > hexazinone (8.8 ��g l -1) > atrazine (45 ��g l-1) > simazine (150 ��g l-1) > tebuthiuron (175 ��g l-1) > ionynil (> 1 mg l-1). Similar absolute and relative toxicities were observed with colonies of the coral Acropora formosa (Irgarol 1051 EC50: 1.3 ��g l-1, diuron EC50: 2.8 ��g l-1), Time-course experiments indicated that ��F/Fm��� was rapidly reduced (i.e. within minutes) in S. hystrix exposed to Irgarol 1051 and diuron. On return to fresh running seawater, ��F/Fm��� recovered quickly in diuron-exposed corals (i.e. in minutes to hours), but slowly in corals exposed to Irgarol 1051 (i.e. hours to days). Time-course experiments indicated that the effects of diuron (3 ��g l-1) on S. hystrix were inversely related to temperature over the range 20 to 30 ��C, although initially the effects were less at the lower temperatures. Repeated exposure to pulses of Irgarol 1051 (daily 2 h exposure to 30 ��g l -1 over 4 d) resulted in a 30% decrease in the density of symbiotic dinoflagellates in the tissues of S. hystrix.

Preliminary evaluation of the occurrence of herbicides and PAHs in the Wet Tropics region of the Great Barrier Reef, Australia, using passive samplers

The proximity of the Great Barrier Reef (GBR) Marine Park to areas of intensive agriculture and increasing urbanisation places the park under potential threat of contamination by land-based pollutants. Passive samplers were deployed at inshore reef and river mouth sites in the Wet Tropics region of the GBR during a dry and a wet season to measure levels of land-based organic pollutants in this environment. Two types of passive sampling devices were deployed: (i) a polar sampler, which can be used to monitor polar herbicides and (ii) semipermeable membrane devices (SPMDs) which sequester more hydrophobic compounds (e.g. PAHs, chlorpyrifos). Herbicides (diuron, simazine, atrazine, hexazinone and/or flumeturon) were detected at low concentrations (ng L-1) at all sites sampled and in both seasons. Chlorpyrifos was not detected while PAHs were present in SPMDs at levels below limits of detection. The results show that the GBR environment does contain low levels of organic pollutants and that passive sampling provides a sensitive monitoring tool for measuring waterborne organic pollutants. (c) 2005 Elsevier Ltd. All rights reserved.

Herbicide contamination and the potential impact to seagrass meadows in Hervey Bay, Queensland, Australia

Low concentrations of herbicides (up to 70 ng 1(-1)), chiefly diuron (up to 50 ng 1 (-1)) were detected in surface waters associated with inter-tidal seagrass meadows of Zostera muelleri in Hervey Bay, south-cast Queensland, Australia. Diuron and atrazine (up to 1. 1 ng g(-1) dry weight of sediment) were detected in the sediments of these seagrass meadows. Concentration of the herbicides diuron, simazine and atrazine increased in surface waters associated with seagrass meadows during moderate river flow events indicating herbicides were washed from the catchment to the marine environment. Maximum herbicide concentration (sum of eight herbicides) in the Mary River during a moderate river flow event was 4260 ng 1(-1). No photosynthetic stress was detected in seagrass in this study during low river flow. However, with moderate river flow events, nearshore seagrasses are at risk of being exposed to concentrations of herbicides that are known to inhibit photosynthesis. (c) 2004 Elsevier Ltd. All rights reserved.

Phytotoxicity of surface waters of the Thames and Brisbane River Estuaries: A combined chemical analysis and bioassay approach for the comparison of two systems

The Thames Estuary, UK, and the Brisbane River, Australia, are comparable in size and catchment area. Both are representative of the large and growing number of the world's estuaries associated with major cities. Principle differences between the two systems relate to climate and human population pressures. In order to assess the potential phytotoxic impact of herbicide residues in the estuaries, surface waters were analysed with a PAM fluorometry-based bioassay that employs the photosynthetic efficiency (photosystem II quantum yield) of laboratory cultured microalgae, as an endpoint measure of phytotoxicity. In addition, surface waters were chemically analysed for a limited number of herbicides. Diuron atrazine and simazine were detected in both systems at comparable concentrations. In contrast, bioassay results revealed that whilst detected herbicides accounted for the observed phytotoxicity of Brisbane River extracts with great accuracy, they consistently explained only around 50% of the phytotoxicity induced by Thames Estuary extracts. Unaccounted for phytotoxicity in Thames surface waters is indicative of unidentified phytotoxins. The greatest phytotoxic response was measured at Charing Cross, Thames Estuary, and corresponded to a diuron equivalent concentration of 180 ng L-1. The study employs relative potencies (REP) of PSII impacting herbicides and demonstrates that chemical analysis alone is prone to omission of valuable information. Results of the study provide support for the incorporation of bioassays into routine monitoring programs where bioassay data may be used to predict and verify chemical contamination data, alert to unidentified compounds and provide the user with information regarding cumulative toxicity of complex mixtures. (c) 2005 Elsevier B.V. All rights reserved.

Environmental analysis of polar herbicides in complex organic-rich matrices by high performance liquid chromatography atmospheric pressure ionization mass spectrometry (HPLC-API-MS)

A comprehensive forensic investigation of sensitive ecosystems in the Everglades Area is presented. Assessing the background levels of contamination in these ecosystems represents a vital resource to build up forensic evidence required to enforce future environmental crimes within the studied areas. This investigation presents the development and validation of a fractionation and isolation method for two families of herbicides commonly applied in the vicinity of the study area, including phenoxy acids like 2,4-D, MCPA, and silvex; as well as the most common triazine-based herbicides like atrazine, prometyne, simazine and related metabolites like DIA and DEA. Accelerated solvent extraction (ASE) and solid phase extraction (SPE) were used to isolate the analytes from abiotic matrices containing large amounts of organic material. Atmospheric-pressure ionization (API) with electrospray ionization in negative mode (ESP-), and Chemical Ionization in the positive mode (APCI+) were used to perform the characterization of the herbicides of interest.

Otimiza����o e valida����o de metodologia anal��tica empregando SPE e LC-ESI-MS/MS para determina����o de multiclasses de agrot��xicos e metab��litos em ��gua de superf��cie e de abastecimento p��blico

A aplica����o de agrot��xicos nas pr��ticas agr��colas aumentou muito nos ��ltimos anos. Isto vem ocorrendo devido ao crescimento populacional, demandando maior produ����o de alimentos. O uso de agrot��xicos e seus res��duos tornaram-se um problema devido a poss��vel contamina����o das ��guas de superf��cie e subterr��nea, podendo impactar o meio ambiente e causar danos �� sa��de p��blica. Na cidade de Rio Grande, RS, Brasil, o suprimento de ��gua pot��vel �� realizado pela CORSAN (Companhia Riograndense de Saneamento), que capta a ��gua do Canal S��o Gon��alo, o qual estabelece uma liga����o entre as duas lagoas: Lagoa dos Patos e Lagoa Mirim. Em suas margens h�� tamb��m a capta����o de ��gua para irriga����o das culturas agr��colas. Esta intera����o entre o uso da ��gua das lagoas e a agricultura, pode resultar na contamina����o das ��guas que s��o captadas para abastecimento dos munic��pios situados na regi��o. Uma metodologia anal��tica empregando Extra����o em Fase S��lida (SPE) e Cromatografia L��quida acoplada a uma fonte de ioniza����o por Electrospray tandem Espectrometria de Massas (LCESI-MS/MS) foi desenvolvida e validada para a determina����o de dezoito agrot��xicos multiclasses (herbicidas, inseticidas e fungicidas) e dois metab��litos em amostras de ��gua superficial e de abastecimento p��blico. Esta metodologia foi aplicada para monitoramento durante dez meses na ��gua superficial do Canal S��o Gon��alo e na ��gua de consumo da cidade de Rio Grande, ap��s o tratamento pela CORSAN. Os agrot��xicos selecionados foram: clomazona, bispiribaque-s��dio, diurom, atrazina, simazina, imazetapir, imazapique, metsulfuron-met��lico, quincloraque, penoxsulam, 2,4-D, pirazosulfuron-et��lico, bentazona, propanil, irgarol, tebuconazol, fipronil e carbofurano. Os metab��litos foram: 3,4-DCA e 3-hidroxicarbofurano. Os limites de detec����o do m��todo variaram entre 0,4 ��� 40,0 ng L -1 , enquanto para os limites de quantifica����o a varia����o foi de 4,0 ��� 100,0 ng L -1 . Todos os compostos apresentaram excelente linearidade, com coeficiente de determina����o maior do que 0,99. As recupera����es empregando SPE com cartuchos contendo 500 mg de C18ec, variaram entre 70 a 120%, para 95% dos compostos, apresentando %RSD 20%. Atrav��s do monitoramento de m��ltiplas rea����es (MRM), duas transi����es diferentes (��on precursor ��� ��on produto) foram selecionadas para cada composto, uma para quantifica����o e outra para confirma����o, o que aumentou a seletividade do m��todo. Para as amostras analisadas, foram detectados agrot��xicos n��vel de ng L -1 . O m��todo desenvolvido �� sens��vel, r��pido e apresenta elevada seletividade, permitindo a identifica����o e a quantifica����o dos agrot��xicos em ��guas superficiais e de abastecimento p��blico, atendendo os n��veis requeridos pelos ��rg��os reguladores como da Uni��o Europ��ia (98/83/EC) e do Brasil segundo a Portaria N��. 518 (25/03/2004).