Metodologia para análise do herbicida sulfentrazona em água e solo.

Sulfentrazona é um herbicida bastante utilizado nas grandes culturas de soja e de cana-de-açúcar. O impacto ambiental associado a este herbicida é devido a seu elevado potencial de lixiviação e persistência, portanto o estudo do destino deste composto é de fundamental importância. O objetivo deste trabalho foi validar uma metodologia para análise deste herbicida em amostras de solo e água. A extração da sulfentrazona em solo foi realizada utilizando solução de acetona-HCl 0,25 mol L-1, sob refluxo durante 1 hora, seguida de filtração e concentração em rotaevaporador a 40 0C. A purificação do extrato de solo e concentração do analito foi realizada por extração em fase sólida (SPE), utilizando-se duas fases adsorventes C8 e sílica gel. Amostras de água também foram extraídas e purificadas em fase sólida. A identificação e quantificação do composto de interesse foi realizada por cromatografia gasosa, detecção por captura de elétrons, em coluna DB 608 (30 m x 0,53 mm x 0,83 µm).O limite de detecção foi fixado em 0,01 µg mL-1. A validação do método para a matriz de solo foi feita com fortificação no nível de 0,05 mg kg -1 e para água 0,005 mg L -1. A eficiência do método aplicado foi avaliada em função dos valores de recuperação do pesticida em amostras fortificadas. Todos os valores de recuperação obtidos estiveram dentro da faixa de aceitabilidade de 70 a 120%

Determination of metsulfuron-methyl residues in elephant grass by using (LC/ESI)-Q-ToF-MS/MS (813).

Elephant grass has been used as animal feed and also in diff erent applications, such as, to protect arid land from soil erosion, to improve the fertility of soil, to use as fi rebreaks and windbreaks, and to produce bio-oil, alcohol and charcoal. However, one of the its limitation in fi eld implantation in large scale is the interference of weeds. In order to control the infestation of weeds the application of herbicides has been showed to be an eff ective method, but due to the toxicity of these substances for the environment and animals, the presence of the herbicides residues in plants must be evaluated. Thus, this work presents an analytical method, which was developed to determine the residues of metsulfuron-methyl in elephant grass by using Liquid chromatography coupled to a quadruplole time-of-fl ight tandem mass spectrometry (LC/ESI)- Q-ToF-MS/MS. The extraction of the analyte was made by using the QuEChERS method (quick, easy, cheap, eff ective, rugged and safe). In the clean-up step, besides PSA and MgSO4, florisil was also used to remove the interferents. The separation was carried out on an Acquity UPLC® BEH C18 column (1.7 ?m, 2.1mm ID, 100mm) using a gradient elution profi le and mobile phase consisting of 0.1 % formic acid in water and methanol (positive-ion mode). The method showed good linearity in the concentration range of 0.001?0.2 ?g/mL, (r2 ? 0.99); the limit of quantifi cation (LOQ) was 20 ?g/kg-1; the recoveries were in the range of 93?120% and the precision (RSD%) was 12.7 %. The method was applied to analyze samples collected after 45 d after treatment with metsulfuron-methyl (7.8 and 15.6 g ha-1) and an untreated check. None of the sample showed the presence of the herbicide residues above of the limit of quantifi cation (LOD). Acknowledgements: Financial support of CNPq and FAPEMIG is highly acknowledged

Spray drift and pest control from aerial applications on soybeans.

Abstract: Pesticide drift is an issue in modern farming, mainly for crops under constant spraying as soybeans. This study aimed at assessing drift and pest control for aerial applications in soybean crops. Hydraulic nozzles and rotary atomizers, regulated to a wide spectrum of droplet sizes, sprayed thiamethoxam plus lambda-cyhalothrin using an agricultural aircraft Ipanema 202A at volume rate of 20 L ha?1. Treatments consisted of testing two devices: a rotary cage atomizer (Micronair AU 5000) with blade angles of 65° for larger droplets, and with angle of 55° for smaller ones; and a set of adjustable nozzles (Stol model) with deflector angle of 90° for smaller droplets, and with angle of 30° for larger ones. Drift was evaluated through quantification of active ingredient, by means of liquid chromatography, on nylon strings set 20, 40, 80, 160 and 320 m downwind from the applied area. Control efficiency was measured by counting caterpillars and stinkbugs found five days after spray. Rotary atomizers produced lesser drift compared to adjustable nozzles at the designed setting. Furthermore, drift can be reduced through a suitable regulation of the devices, keeping an effective pest control

Exploring different approaches to obtain Piper aduncum nanoformulations.

Abstract: Plant essential oils have been recognized as important natural resources for prospecting new biopesticides. Piper aduncum, an abundant plant in the Amazon region, displays insecticidal and fungicidal properties. In this study, nanoformulations containing the essential oil of Piper aduncum were prepared using two protocols: poly (ɛ- caprolactone) (PCL) containing Tween 80 as a stabilizer, and Zein protein using Pluronic (poloxamer) copolymer as a stabilizer. The PCL encapsulation approach proved to be a successful strategy for use as a nanocarrier of active compounds for agricultural applications. It can contribute to more effective and environmentally friendly pest management in agricultural systems

Identification of 3-Hydroxymethyl sulfentrazone in rats urine.

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