Nanostructured a-Fe203 (hematite) was produced usíng high-energy ball milling and analized by X-ray diffraction (XRD), 57Fe Mi.issbauer spectrometry and magnetization measurements. The results showed that after 2 h milling, a-Fe203 nanosize particles were obtained about 15 nm. The 57 Fe Mossbauer spectrometry correlated with magnetometry showed also that Morin transition was notobserved after 0,75 h milling.

Son estudiados los procedimientos de producción nanopartículas de hematita, evaluándose preferentemente, las producidasdas por mecanosíntesís, mediante espectroscopia Mossbauer, difracción de rayos X y magnetometría. Se produjeron, luego de 2 horas de tratamiento mecánico, partículas de tamaños alrededor 15 nm. La técnica de producción por mecanosíntesis no implicó transformación estructural de la fase cristalográfica inicial. La espectroscopia Mossbauer del 57Fe correlacionada con la magnetometría, mostraron también que la transición de Morín no es observada inmediatamente después de 0,75 horas de mecanosíntesis.

FTIR identified the carbonyl C = O functional group of the anthraquinone derivatives in aqueous macerated and alcoholics purges as aloe plants (Aloe vera L. , Aloe barbadensis Miller ) , senna ( Cassia spp . ) , Rhubarb ( Rheum palmatum) and shell sagrada (Rhamnus Pursiana ) without prior separation of the components by chromatographic methods or other physical and chemical methods . We show that the absorption maxima for the C = O carbonyl group of the anthraquinone derivatives in aqueous and alcoholic macerated Aloe vera and Aloe barbadensis L. Miller- interact with inorganic salts - for a week , as time passes, these maxima moving to higher-frequency areas . This procedure can be recommended for detection of anthraquinone derivatives in encapsulated pharmaceutical preparations and extracts of the plants mentioned purgatives

Por FTIR se identifica al grupo funcional carbonilo C=O de los derivados antraquinónicos en macerados acuosos y alcohólicos de plantas purgantes como aloes (Aloe vera L., Aloe barbadensis Miller), sen (Cassia sp.), ruibarbo (Rheum palmatum) y cáscara sagrada (Rhamnus pursiana), sin separación previa de los componentes por métodos cromatográficos u otros métodos físico químicos. Se demuestra que los máximos de absorción para el grupo carbonilo C=O de los derivados antraquinónicos en macerados acuosos y alcohólicos de Aloe vera L. y Aloe barbadensis Miller -interactúan con sales inorgánicas durante una semana-, conforme transcurre el tiempo, estos máximos se desplazan a zonas de mayor frecuencia. Este procedimiento puede recomendarse para la detección de los derivados antraquinónicos en extractos y preparados galénicos encapsulados de las plantas purgantes mencionadas

Pectin is a mixture of polysaccharides containing galacturonic acid units, as main compound, into its structure and it is found by forming a part of the vegetables cell wall, such as citrus. Carboxylic groups in their anionic form are characterized for their binding capacity for cationic species such as Pb2+. Orange peels were used as a source of pectin, through acid hydrolysis (pH=1.4, temperature: 80°C, time: 60 min.). For decreasing the hydration and swelling capacity when pectin is found in aqueous solution medium, crosslinked by using formaldehyde was made. Maximum sorption capacity was obtained at pH between 4.5 and 5.5. The most of the cases Pseudo first arder mathematic kinetic model fit it better than Pseudo second arder to kinetic biosorption of lead in pectin for either difierent initial metal concentrations in solution or difierent amounts of biosorbent.

La pectina es una mezcla de polisacáridos que presentan principalmente unidades de ácido galacturónico en su estructura y se encuentra formando parte de la pared celular de vegetales como los cítricos. Los grupos carboxílicos en su forma anionica se caracterizan por tener tendencia hacia la captación de especies catiónicas como Pb2+. La fuente empleada para la obtención de pectina, mediante hidrólisis ácida (pH = 1.4, temperatura: 80°C tiempo: 60 min.) fueron las cáscaras de naranja. Para disminuir la capacidad de hidratación e hinchamiento de la pectina cuando se encuentra en medio acuoso se realizó la reticulación empleando formaldehído. El rango de pH en el cual se obtuvo la máxima capacidad de sorción fue 4.5 - 5.5. En la mayoría de los casos el modelo matemático de cinética de Pseudo primer orden se ajustó mejor que Pseudo segundo orden a la cinética de biosor...

Seeds of chirimoya and guanabana from the communities of Cumbe and Callahuanca - Yauyos, Lima were analyzed. The extraction of natural toxic was realized using ethanol as the optimal solvent, after several solvent tests, phytochemicals analysis identified :saponins, coumarins, tannins, quinones and essential oils, mostly castor oil which was confirmed by FTIR spectra. Qualitative analysis results identified: PO4(3-), AsO4(3-) and others. Toxicological tests extracts applied on larvae and fruit flies finding levels of mortality as 88% to 94% on chirimoyas and guanabanas respectively.

Seeds of chirimoya and guanabana from the communities of Cumbe and Callahuanca - Yauyos, Lima were analyzed. The extraction of natural toxic was realized using ethanol as the optimal solvent, after several solvent tests, phytochemicals analysis identified :saponins, coumarins, tannins, quinones and essential oils, mostly castor oil which was confirmed by FTIR spectra. Qualitative analysis results identified: PO4(3-), AsO4(3-) and others. Toxicological tests extracts applied on larvae and fruit flies finding levels of mortality as 88% to 94% on chirimoyas and guanabanas respectively.

Aqueous extractions were performed controlling the pH with CaCO3 and Ca(OH)2, using as clarifiers activated coal and activated clays in cold and warm solutions to obtain best results with cold bentonite, warm activated clay and warm activated coal. Analytical results were compared with a commercial sample of stevia.

Aqueous extractions were performed controlling the pH with CaCO3 and Ca(OH)2, using as clarifiers activated coal and activated clays in cold and warm solutions to obtain best results with cold bentonite, warm activated clay and warm activated coal. Analytical results were compared with a commercial sample of stevia.