Research was conducted in 2014 to evaluate the efficacy of harvest-aid systems and the performance of harvest aids applied at various timings in Mid-South soybean production. Evaluations included yield, desiccation, green stems and pods, and seed quality. Saflufenacil did not perform as well as the producer standard 14 DAT at the Starkville, MS location with desiccation levels of 78 and 98%, respectively. However, similar performance was observed 14 DAT at the Brooksville, MS location. When applied at R6.5, paraquat based treatments improved desiccation and reduced green stem 7 DAT compared to other treatments. No yield differences were observed between harvest aid treatments. However, yield differences were observed between the R6.0 and R6.5 timings. These data suggest saflufenacil is an effective harvest aid option, but may require up to 14 days for optimum desiccation. In addition, yield is not impacted by harvest aid product, but rather the timing of the application.

Research was conducted at the Mississippi State University Delta Research and Extension Center from 2015 to 2018 to (1) determine the effects of sub-lethal concentrations of paraquat, metribuzin, fomesafen, and cloransulam-methyl applied at different rice growth stages, determine the effects on rice growth of simulated off-target paraquat applications at varying concentration based on a proportionally decreased carrier volume characterize rice response to a sub-lethal concentration of paraquat in combination with common POST and residual herbicides, assess whether starter N fertilizer or different N fertilizer management strategies can aide in rice recover after exposure to a sub-lethal concentration of paraquat, and define a maximum soil concentration of S-metolachlor that will allow rice to germinate and emerge. Rice yield was negatively affected following exposure to paraquat applied any time after rice emergence. Paraquat applications to rice in early reproductive growth reduced rough rice yield and seed germination the greatest. Paraquat plus metribuzin injured rice 68 to 69% 14 and 28 d after treatment (DAT), which was 10 to 13% greater than following paraquat alone or paraquat plus fomesafen. Pooled across metribuzin and fomesafen treatments, paraquat reduced rough rice yields 23%. Paraquat plus 10 different residual herbicides injured rice ≥51% 28 DAT and reduced rough rice yields ≥21%. In spite of starter N fertilizer applications, paraquat injured rice ≥41%, reduced height 57%, reduced dry weight prior to flooding 77%, delayed maturity 10 d, reduced dry weight at maturity 33%, and reduced rough rice yield 35%. Similar results were observed in the N Fertilizer Timing Study. Soil concentrations of s-metolachlor 28 DAT were 30, 31, 32, 36, 61, and 488 ppm following exposure to s-metolachlor applied at 0, 1/64, 1/32, 1/16, 1/4, and 1X concentration. A soil analysis would be the best option to determine levels of s-metolachlor prior to planting rice if an off-target herbicide movement containing s-metolachlor occurred. These data indicate that paraquat can have negative impact on rice growth and development. Therefore, it is crucial that if environmental conditions are conducive for off-target herbicide movement extreme caution should be exercised when applying paraquat adjacent to fields devoted to rice production.

<p>Parkinson’s Disease (PD) and Alcohol Use Disorder (AUD) are neurodegenerative conditions that involve similar neurobiological pathways and affect motivation and reward dysregulations. This project aims to explore whether PD-related insults affect alcohol-related motivation and reward. We utilized paraquat (PQ) exposure as a neurotoxicant-induced model for PD and mice selectively bred for a differential in alcohol preference as a model for genetic and neurobiological susceptibility for high/low alcohol consumption. In Experiment 1, binge-like alcohol drinking after three weeks of PQ exposure (10 mg/kg, i.p. once per week) or saline was assessed in HAP male and female mice. The four-day Drinking in the Dark (DID) procedure was used to induce binge-like alcohol drinking. Dorsal (DS) and ventral (VS) striatal catecholamines were analyzed after DID. Overall, PQ-treated HAP males had significantly lower alcohol intake than saline-treated males. This effect was absent in female HAP mice. Catecholamine quantification showed lower DOPAC levels in VS of PQ-treated vs. saline-treated HAP male mice. Experiment 2 assessed alcohol-induced locomotor sensitization in adult male and female high (HAP) and low-alcohol-preferring (LAP) mice after PQ exposure. Following the same 3 weeks of PQ or saline exposure, mice received 6 sensitization induction days with either 3 g/kg i.p. EtOH or saline. On test day, an alcohol challenge dose of 2 g/kg in all mice was used to determine the expression of locomotor sensitization. PQ exposure had no significant effect on locomotor activity and sensitization. However, PQ-treated mice showed great variability in their alcohol-induced locomotor activity compared to other groups. These data suggest a sex difference in PQ’s effect on alcohol binge-like drinking. However, PQ’s effect on alcohol-induced locomotor sensitization is not conclusive. This project will elucidate potential mechanisms behind PD-related neuropsychiatric comorbid conditions like AUD. Such findings may assist in early diagnosis and treatment refinement, as these comorbidities precede the motor manifestation of PD by decades and significantly impact the quality of life.</p>

Argentina es un destacado productor de semillas híbridas de girasol. La desecación química se emplea para adelantar la cosecha y reducir la incidencia de adversidades bióticas y abióticas. En cultivos para semilla, se desconoce el efecto de la práctica sobre la dinámica de secado de la planta en parentales femeninos, el rendimiento o la calidad del aceite de las semillas híbridas, la calidad fisiológica a cosecha y durante el almacenamiento y el posterior desempeño a campo. El objetivo general de esta tesis fue analizar el efecto del desecado químico en la deshidratación de la planta, el rendimiento de líneas parentales femeninas, la composición acídica y la calidad fisiológica de las semillas híbridas de girasol. Se realizaron siete experimentos en Buenos Aires y Venado Tuerto, utilizando seis parentales femeninos con diferente constitución genética y composición de aceite (alto oleico y alto linolénico). Los desecantes, Paraquat, Carfentrazone y Saflufenacil se aplicaron en el rango de 38-15 % de humedad de semillas. El Control permaneció en el campo hasta alcanzar 10 a 12 % de humedad. El Paraquat tuvo el mayor efecto desecante. La dinámica de secado fue diferente entre órganos, los frutos (semillas) se secaron más rápidamente que los receptáculos y tallos. Los indicadores visuales (necrosis y verdor) no se asociaron con la pérdida efectiva de humedad de los diferentes tejidos. La aplicación del desecante alrededor del 30% de humedad de semillas, anticipó la cosecha entre 23 y 43 días, sin efectos adversos sobre el rendimiento de las líneas parentales, ni el contenido o la composición de aceite de las semillas híbridas. El desecado no afectó la viabilidad (90- 100%), aunque incrementó la dormición entre un 51 a 96 %. La cubierta seminal mostró una importante influencia en los niveles de dormición de las semillas de girasol tratadas con Paraquat, asociado con el aumento en el espesor de la pared celular externa de la capa de células endospermáticas. La desecación química con Paraquat benefició la calidad fisiológica de las semillas de girasol. Incrementó un 3 a 19 %, la germinación medida en semillas despiertas luego de la remoción del pericarpio + cubierta seminal. El vigor (estimado mediante de la Conductividad Eléctrica en semillas sin pericarpio) también fue mayor, con reducciones entre 0,9 a 50,2 μS.cm-1. g-1 respecto del control. La mejora en la calidad de las semillas cosechadas anticipadamente se asoció con una reducción en la exposición a condiciones ambientales adversas y resultó independiente de la constitución genética de los híbridos. Los genotipos alto y mid oleico tuvieron menor calidad fisiológica. El Paraquat también benefició la germinación y el vigor durante el almacenamiento prolongado en galpón y cámara fría, sin efectos fitotóxicos. Los pequeños cambios en el contenido de aceite u oleico durante el almacenamiento, no se tradujeron en cambios en los niveles de germinación y vigor. La tasa de emergencia a campo (a los 6 y 19 meses desde cosecha) fue mayor en las semillas desecadas, con un mejor ajuste cuando se expresó en grados día/plántula. Los beneficios del desecado químico descriptos en el presente trabajo, contribuyen a optimizar el proceso de producción y almacenamiento de las semillas de girasol. / Argentina is a leading producer of sunflower hybrid seeds. Chemical desiccation is used to advance the harvest and reduce the incidence of biotic and abiotic adversities. In seed crops the effect of desiccation on drying rate of female parents plants, hybrid seeds yield or oil quality, physiological quality at harvest and during storage, and subsequent field performance, is unknown. The general objective of this thesis was to analyze the effect of chemical desiccation on plan drying, yield from female parents plants, acidic composition and physiological quality of hybrids sunflower seeds. Seven experiments were performed in Buenos Aires and Venado Tuerto using six female parents with different background genetic and seed oil composition (high oleic and high linoleic). Desiccants, Paraquat, Carfentrazone and Saflufenacil, were applied when the seeds presented between 38 and 15% moisture. Control remained in the field until reaching 10 to 12% seed moisture. Paraquat had the highest desiccation effect. The drying rate was different among organs, with fruits (seeds) drying faster than the receptacles and stems. Visual indicators (necrosis and greenery) were not associated with the effective moisture loss from the different tissues. Desiccant application around 30% seed moisture, advanced harvest between 23 and 43 days without adverse effects on the female parents yield, content or oil composition of hybrid seeds. Desiccation did not affect the viability of hybrid seeds (90-100%), although it increased dormancy between 51 to 96 %. The seed coat showed a significant influence on levels of dormancy of sunflower seeds treated with Paraquat, associated with the increase in the thickness of the outer cell wall layer of endospermatics cells. The chemical desiccation with Paraquat was beneficial to physiological quality of sunflower seeds. It increased the germination in seeds without dormancy after pericarp and seed coat removal by 3 to 19%. The vigour (estimated by electrical conductivity in seeds without pericarp) was also higher, with decreases between 0,9 to 50,2 μS.cm-1. g-1 compared to the control. The improvement in the quality of seeds harvested early was associated with a reduction in exposure to adverse environmental conditions. And it was independent of the genetic constitution of the hybrids. The high and mid oleic genotypes had lower physiological quality. Paraquat also had beneficial effects on germination and vigor during prolonged storage in room and cold chamber, without phytotoxic effects. Small changes in oil or oleic content during storage did not represent changes in germination and seed vigor levels. The field emergency rate (at 6 and 19 months after harvest) was higher in the desiccated seeds, with a better fit when expressed in degrees day/seedling. The benefits of chemical desiccation described by this work help the optimization of production processes and storage of sunflower seeds.

The exploitation of the relationship between the chemical and physical properties of materials is the hallmark of advancing science throughout the world. The basic understanding of how and why molecules react and interact with each other in different environments allows for the discovery and implementation of new materials and devices that not only advance the state of human life but continually change the planet. The work described in this dissertation generally falls under three diverse categories: functionalization of fullerenes, investigation of host/guest interactions in solution, and the synthesis and characterization of ion containing polymers. The separation and functionalization of fullerenes is a recent and exciting area of research. The separation methods outlined are intended to increase the availability of endohedral metallofullerenes by decreasing their cost of production. Functionalized fullerene species were achieved through Bingel and Prato reactions to provide materials with novel functional groups. These materials may be further utilized in photovoltaic or other organic electronic devices. The characterization of noncovalent interactions between different molecules in solution is the focus of supramolecular chemistry. Isothermal Titration Calorimetry stands out as one of the best, among the many methods used to elucidate the characteristics of these systems. The binding of bis- imidazolium and paraquat guests with macrocyclic host molecules has been explored in this work. The measurements of the association constants for these systems will aid in the ongoing synthesis of new host/guest systems. Ion containing polymers were synthesized and characterized for their use in electroactive devices. Imidazolium containing polymers with bulky anions were synthesized on low glass transition polymer chains. These materials had enhanced ion conductivity and may eventually be used in electronic actuator materials. / Ph. D.

The effect of Mn(III)-salophen, a superoxide scavenger, against oxidative stress was evaluated in <i>Escherichia coli sodA- sodB-</i>. Oxidative stress was imposed by exposure of the cells to paraquat or hyperoxia. Cells were grown in LB medium overnight, washed and resuspended in the indicated glucose/salts medium supplemented with casamino acids. The effect of Mn(III)-salophen in the oxidative stress model <i>in vivo</i> was measured in terms of the cell growth. Mn(III)-salophen ( 60 nM) completely protected <i>E. coli</i>JI132<i>sodA- sodB-</i>against 1.0 μM paraquat. Equivalent amounts of Mn(III) acetate, a Mn(III)-salophen component, also protected against paraquat toxicity in aerobic <i>E. coli</i> JI132<i>sodA- sodB-</i>. Fe(III)-salophen which has no superoxide scavenging activity, did not protect the cells against paraquat toxicity. The protective effect of Mn(III)-salophen against the paraquat toxicity was proposed to come from the intracellular superoxide scavenging activity of either the complex itself, its component Mn(III), or both, but not by inhibiting the uptake of paraquat. The protective effect of Mn(III)-salophen and Mn(III) in the glucose/salts medium containing casamino acids was also observed in <i>E. coli sodA- sodB-</i> in 100% and 50% oxygen. Hyperoxia increases intracellular levels of superoxide radicals that are intercepted by Mn(III)salophen and Mn(III). / Master of Science

Production of efficiently synthesizable, strongly associating crown ether-based cryptands is desired for pseudorotaxane complexation of bipyridinium guests to produce suprapolymers and supramolecularly-linked block copolymers. Cryptands based on bis(meta-phenylene)-32-crown-10 (BMP32C10) were synthesized. The functionality of phenylenemethanol-BMP32C10 cryptand III-3 (Ka = 2.0 x 104 M-1) did not negatively affect binding strength, although the strength of complexation is marginal to achieve the desired suprapolymers. The cryptand dimethylpyridyl-BMP32C10 IV-2 was synthesized in an attempt to improve over the binding ability of the pyridyl-BMP32C10 cryptand IV-1; instead, interesting host design insights were discovered as binding strengths were reduced over 1000-fold. The crystal structure of IV-2 shows acyl-aryl conjugation which limits the host's ability to accept guests. Synthesis of larger cis-di(carbomethoxybenzo)-3n-crown-n crown ethers was explored using the high concentration, template technique previously reported for cDB24C8 diester. cDB30C10 diester (V-1c) was produced in 93% yield; the desired pyridyl-cDB30C10 cryptand V-12 binds paraquat strongly (Ka = 1-2x105 M-1) and diquat stronger than any other host (Ka = 1.9x106 M-1), both in 1:1 fashions; association constants were measured by ITC. X-ray crystallography of the complexes shows the cryptand's para arm is too far away to interact with paraquat and the host has numerous bifurcated interactions with diquat, explaining the difference in binding strengths. Syntheses of the regioisomers of cDB27C9 diester was also explored; the cyclization yields (cDB27C9S, VI-2: 59% and cDB27C9L, VI-3: 44%) are lower, likely due to poor attack angles due to mismatched arm length in cyclization, than the equivalent length ethyleneoxy-armed cDB24C8 and cDB30C10. Modeling of the cryptand isomers, pyridyl-cDB27C9S and pyridyl-cDB27C9L, showed that the former should improve para arm interaction with paraquat, but should be sterically hindered for diquat and the latter should have a highly flexible, poorly preorganized interaction with either type of guest. ITC, MS, and crystallography data supported the predictions. Derivatization of the pyridyl-cDB30C10 cryptand V-12 was explored using chelidamic acid (VII-1). Schemes yielding alcohol, alkyl halide, alkyne, and TEMPO functionality were followed, but failed. Currently, functionalized cryptand derivatives have not been achieved, future directions are proposed. / Ph. D.

Mutations in the AAAS gene coding for the nuclear pore complex protein ALADIN lead to the autosomal recessive disorder triple A syndrome. Triple A patients present with a characteristic phenotype including alacrima, achalasia and adrenal insufficiency. Patient fibroblasts show increased levels of oxidative stress, and several in vitro studies have demonstrated that the nucleoporin ALADIN is involved in both the cellular oxidative stress response and adrenal steroidogenesis. It is known that ALADIN knock-out mice lack a phenotype resembling human triple A syndrome. The objective of this study was to determine whether the application of chronic oxidative stress by ingestion of paraquat would generate a triple A-like phenotype in ALADIN null mice. Adult male mice were fed either a paraquat (0.25 g/kg diet) or control diet for 11 days. After application of chronic oxidative stress, ALADIN knock-out mice presented with an unexpected compensated glutathione metabolism, but lacked a phenotype resembling human triple A syndrome. We did not observe increased levels of oxidative stress and alterations in adrenal steroidogenesis in mice depleted for ALADIN. This study stresses the species-specific role of the nucleoporin ALADIN, which in mice involves a novel compensatory mechanism for regulating the cellular glutathione redox response.

Made available in DSpace on 2014-06-11T19:30:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-03-27Bitstream added on 2014-06-13T20:21:01Z : No. of bitstreams: 1 santos_cm_dr_botfca.pdf: 1215927 bytes, checksum: 270920627d6ae63331e38022b7c13faa (MD5) / A cana-de-açúcar é uma cultura de grande importância econômica no mundo. No Brasil, sua expansão tem sido impulsionada para novas áreas agrícolas não tradicionais que apresentam deficiência hídrica. Estudos que visam à seleção de cultivares que apresentem tolerância aos estresses ambientais se constituem numa alternativa viável para aumentar a produtividade nessas regiões. Neste sentido, o objetivo deste trabalho foi estudar de maneira comparativa as respostas fisiológicas e bioquímicas em cana-de-açúcar cultivada sob deficiência hídrica bem como analisar os efeitos fisiológicos do herbicida Paraquat, visando constituir uma alternativa para caracterizar cultivares tolerantes em programas de melhoramento genético da cana-de-açúcar. Para isso, experimentos foram conduzidos em vasos em casa de vegetação e no laboratório da Unidade de Pesquisa e Desenvolvimento da APTA em Jaú (SP). Foram utilizadas quatro cultivares de cana-de-açúcar RB92579, SP81-3250, SP83-2847 e IAC91-5155 em cada experimento. Para o estudo de deficiência hídrica, a primeira avaliação foi realizada nas plantas sem estresse após 85 dias do plantio, em seguida foram implementados dois tratamentos, sem deficiência (-D) e com deficiência (+D) por suspensão da rega por 15 dias e posterior reidratação por 12 dias. Para os estudos com herbicida Paraquat (PQ) um segundo experimento foi instalado dividido em duas partes. Na primeira, foi pulverizado Paraquat, na dose de 150 μM, 24 horas antes das avaliações em plantas conduzidas simultaneamente ao experimento de deficiência hídrica. Na segunda parte, segmentos foliares das cultivares foram cortados em discos e imersos em solução de Paraquat em placas de Petri e analisados quanto à degradação de clorofila. Todos os experimentos foram conduzidos em delineamento inteiramente casualizado, em... / Sugarcane is one of the most economically important crops used in the production of sugar and of bioethanol. In Brazil, this plant has been introduced to non-traditional agricultural areas, with adverse agro-climatic conditions where water deficit is highlighted. Studies aimed at selecting drought-tolerant cultivars are a viable alternative to increase the productivity of these regions. The main goal of this research includes to study comparatively the physiological and biochemical responses in sugarcane under drought stress and recovering as well as analyzing the physiological effects induced by the herbicide paraquat, aiming to establish a scoring system for selecting sugarcane drought tolerant cultivars in breeding programs. The experiments were carried out in a greenhouse located in the Unit of Research and Development of APTA, Jaú, SP., where the cultivars RB92579, SP81-3250, SP83-2847 and IAC91-5155 were grown in pots and used for each set of experiments. For the study of water stress, the first assessment was done in plants without stress after 85 days of planting, and after that two treatments were implemented, i.e. without water deficit (-D) and with water deficit (+D) by withholding in the water supply for 15 days and rewatering for 12 days after the stress period. For the study of paraquat (PQ), another set of experiments were carried out simultaneously to the water stress experiments. Two different experimental methods were used for spraying the PQ solution (150 μM). In the first one, the PQ solution was sprayed onto leaves of the sugarcane plants and the assessments took place 24 hours after spraying. In the second experiment, leaf disks were floated in PQ solutions for 24 hours for analyzing chlorophyll degradation. All experimental designs were completely randomized in 4x2 factorial scheme (four sugarcane... (Complete abstract click electronic access below)

Orientadora: Profa. Dra. Lúcia Helena Gomes Coelho / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Ciência e Tecnologia Ambiental, 2016. / O uso de pesticidas na agricultura e um dos principais fatores de poluicao do solo e das aguas superficiais e subterraneas, sendo potencialmente danoso ao ambiente e a saude humana. Comumente, os residuos de pesticidas estao presentes em concentracoes baixas, o que torna necessaria a extracao e pre-concentracao do analito a fim de elevar a detectabilidade dessas substancias. Neste trabalho, avaliou-se a viabilidade tecnica de aplicacao da metodologia para extracao e pre-concentracao de tracos do herbicida Paraquat, presente em amostras de agua, por extracao em ponto nuvem, minimizando a utilizacao de solventes organicos toxicos e a geracao de residuos, estrategias de preparo de amostra de grande interesse para as areas de tecnologias verdes. Os procedimentos foram realizados utilizando-se diferentes surfactantes: nao ionico (Triton X-114) e ionicos (SDS ¡V anionico e CTAB ¡V cationico). Testou-se a influencia de composto ionico na amostra para auxiliar a separacao das fases e observou-se que, para o sistema SDS/CTAB, a adicao de 10% de NaCl (m/v) ajudou na separacao da fase micelar em relacao a fase aquosa, porem este sistema nao foi eficaz para a extracao do Paraquat devido ao aspecto coloidal da fase organica. Para o Triton X-114, o composto ionico nao apresentou diferenca significativa na separacao das fases, nao justificando a utilizacao do reagente. Este sistema apresentou resposta linear para solucoes entre 0,2 e 5,0 mg L-1 de Paraquat, com FE de 71 e recuperacao entre 62 e 100% para concentracao de 3 mmol L-1 em surfactante, e, FE 45 e recuperacao de 100% para 6 mmol L-1 em surfactante. A solucao de Triton X-114 3 mmol L-1 apresentou repetibilidade em suas extracoes, com coeficiente de variacao medio de 15,5%, porem nao foi reprodutivel. Para quantificacoes em amostras reais, fez-se necessaria a reacao com ditionito para seletividade do Paraquat, pois substancias presentes na amostra podem ser extraidas e absorverem no mesmo comprimento de onda que o analito de interesse (¿Ü = 258 nm). Os limites de deteccao e quantificacao foram, respectivamente, 15 e 50 £gg L-1 para a leitura direta e 50 e 167 £gg L-1 para a determinacao colorimetrica. Contudo, a aplicacao em amostras reais nao apresentou a mesma eficiencia de pre-concentracao e extracao, sobretudo pela elevada solubilidade do Paraquat em agua, concluindo-se que a tecnica nao se mostrou a mais adequada para a aplicacao proposta. A quantificacao por colorimetria e uma alternativa interessante a determinacao por HPLC por ser mais rapida, menos laboriosa e de menor custo, alem do residuo ser de mais facil disposicao que os solventes organicos convencionalmente utilizados em cromatografia. / The use of pesticides in agriculture is one of the main factors of soil, surface and groundwater pollution, and they are potentially harmful to the environment and human health. Pesticides residues are commonly present at low concentrations, which makes necessary an extraction and pre-concentration step of the analyte in order to increase the detectability of these substances. In this work, it was evaluated the feasibility of application of the extraction and pre-concentration of traces of the herbicide Paraquat present in water samples, using cloud point extraction methodology, minimizing the use of toxic organic solvents and the generation of residues, which are considered strategies of sample preparation with huge interest for green technologies. The procedures were performed using different surfactants: nonionic (Triton X-114) and ionic (SDS - anionic and CTAB - cationic). It was tested the influence of ionic compounds in the sample to aid phase separation and it was observed that, for SDS/CTAB system, the addition of 10% NaCl (w/v) helped the micellar phase separation, but this system was not effective for Paraquat extraction once the organic phase produced had a colloidal aspect . For the Triton X-114, the ionic compound was no significant difference, not justifying the use of the reagent. This system showed linear response between 0.2 and 5.0 mg L-1 of Paraquat, with enrichment factor of 71 and recovery between 62 and 100% with the concentration of 3 mmol L-1 in tensoative, and, enrichment factor 45 to 100% recovery for 6 mmol L-1 in surfactant. The solution of Triton X-114 3 mmol L-1 showed repeatability in the cloud point extraction, with mean variation coefficient of 15.5%, but it was not reproducible. For the measurements using real samples, it was necessary a prior reaction with dithionite for selectivity detection of Paraquat, once many substances present in the water sample can be simultaneously extracted and analysed at the same wavelength as the target analyte (ë = 258 nm). The limits of detection and quantification were, respectively, 15 and 50 ìg L-1 for the direct analysis and 50 and 167 ìg L-1 for the colorimetric determination. However, the application in real samples did not show the same efficiency of pre-concentration and extraction, especially because Paraquat has high solubility in the water, concluding that the technique was not the most suitable for the proposed application. The colorimetric quantification is an interesting alternative to HPLC determination because it is faster, less laborious and lower cost, in addition to generating an easier disposition residue than conventionally organic solvents used in chromatography.