A validated analytical method for the multiresidue analysis of 40 organophosphate pesticides (OPs) and conversion products in raw wool has been developed. The method is based on the selective microwave-assisted extraction (MAE) of raw wool with acetonitrile and analysis of extracts by gas chromatography-flame photometric detector. The optimum MAE conditions were 20 min duration at 80 °C with 30 mL of acetonitrile per gram of wool. A validation study was performed according to the European SANCO guidelines 10684/2009. Limits of detection and quantification for all pesticides tested were from 0.01 to 0.2 mg/kg and from 0.2 to 1.0 mg/kg, respectively. The average recoveries of pesticides spiked at different levels were in the range of 70-120% with relative standard deviations of ≤ 20%. The extraction performance was compared to the one obtained with a reference Soxhlet extraction. The method was also applied in the analysis of real wool (after field application) samples.
In order to evaluate the extraction of pesticide residues that are transferred to the brew during mate drinking process of P.U.1 yerba mate leaves (Ilex paraguariensis), a special device to simulate the way in which mate is drunk in Uruguay was developed. The transfer to the brew of 12 organophosphates, 5 synthethic pyrethroids and one organochlorine pesticide from spiked samples was studied. The relationship between the transfer data thus obtained and physicochemical properties like water solubility (Ws), octanol-water coefficient (Kow) and Henry's constant (H) was evaluated. The extractability of the pesticide residues from yerba mate can be correlated with log Ws and log Kow. These transfer values allowed the calculation of ARLs (acceptable residue level) for the pesticides following Food and Agriculture Organization (FAO), World Health Organizaion (WHO) guidelines. These results can help the future establishment of maximum residue levels (MRLs).
Se presenta en este artículo la comparación de tres controladores de velocidad (regulador cuadrático lineal-LQR-, proporcional integral derivativo-PID-y borroso) con la intención de determinar cuál de ellos ofrece mejor fiabilidad desde una perspectiva software. Para realizar las pruebas necesarias se utilizaron versiones mutantes de controladores bien ajustados, en los que se inyectaron defectos que simulaban errores de programación. Los controladores fueron diseñados para operar un vehículo autónomo terrestre y fueron ajustados por medio de un algoritmo genético. Dado el elevado número de pruebas a efectuar se decidió construir un simulador multicomputador con el que se realizaron más de 90000 ensayos. En cada uno de los ensayos se sometió a cada controlador mutante a la realización de un recorrido, de unos 20 minutos de duración máxima, sobre un suelo ligeramente ondulado. Con los datos obtenidos se generaron las curvas de fiabilidad por el procedimiento de Kaplan-Meier, lo cual permitió la comparación de controladores objetivo del estudio. De las curvas de fiabilidad del software obtenidas se deduce que, en las condiciones experimentales planteadas, el controlador LQR ofrece el mejor comportamiento, el segundo lugar le corresponde al controlador PID y el tercero al controlador borroso.
Autodeclaración del consumo de marihuana, tabaco, alcohol y derivados de cocaína en embarazadas en 2013 y 2016, Montevideo, Uruguay Marijuana, tobacco, alcohol and cocaine use during pregnancy in 2013 and 2016. A self-report study in Montevideo, Uruguay
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