Aflatoxins are highly carcinogenic compounds produced by the fungus Aspergillus flavus. Aspergillus flavus is a phytopathogenic fungus that commonly infects crops such as cotton, peanuts, and maize. The goal of this r...Aflatoxins are highly carcinogenic compounds produced by the fungus Aspergillus flavus. Aspergillus flavus is a phytopathogenic fungus that commonly infects crops such as cotton, peanuts, and maize. The goal of this research was to design an effective method for sample preparation and analysis of aflatoxin B<sub>1</sub> from Aspergillus flavus infected maize kernels. The method involves liquid extraction with a methanol/water solution. The samples were analyzed by liquid chromatography coupled to an electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) operating in positive ion multiple reaction monitoring (MRM) mode. The spiked levels for the recovery experiment were 4 ppb and 20 ppb, respectively. Recoveries ranged between 72% and 113% (90.8% average), with Relative Standard Deviation below 15% (10.6% on average).展开更多
The purpose of this study is to determine the morphological, microstructural characteristics and water diffusion parameters of the Canarium schweinfurthii (CS) shellnut. This work is part of a vast project to valorize...The purpose of this study is to determine the morphological, microstructural characteristics and water diffusion parameters of the Canarium schweinfurthii (CS) shellnut. This work is part of a vast project to valorize the above-mentioned cores for possible industrial use as charges in composites or abrasives materials. The study was based on the characterization of intrinsic physical characteristics of the coreshells scanning electron microscopic (SEM) observations desorption, adsorption and absorption kinetics. The water diffusion phenomenon was modeled and it appears that the Page model well predicted the kinetic of drying, absorption and adsorption. The effective diffusion coefficient and the energy of activation were calculated at three isothermal temperatures (50<span style="white-space:nowrap;">°</span>C, 70<span style="white-space:nowrap;">°</span>C and 90<span style="white-space:nowrap;">°</span>C). There was a tendency for hysteresis in the sorption-desorption cycles. These results strongly predicted the possibility of using these products as a filler in composites, clay building materials and cement because of their high water diffusion stability on a macroscopic scale.展开更多
文摘Aflatoxins are highly carcinogenic compounds produced by the fungus Aspergillus flavus. Aspergillus flavus is a phytopathogenic fungus that commonly infects crops such as cotton, peanuts, and maize. The goal of this research was to design an effective method for sample preparation and analysis of aflatoxin B<sub>1</sub> from Aspergillus flavus infected maize kernels. The method involves liquid extraction with a methanol/water solution. The samples were analyzed by liquid chromatography coupled to an electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) operating in positive ion multiple reaction monitoring (MRM) mode. The spiked levels for the recovery experiment were 4 ppb and 20 ppb, respectively. Recoveries ranged between 72% and 113% (90.8% average), with Relative Standard Deviation below 15% (10.6% on average).
文摘The purpose of this study is to determine the morphological, microstructural characteristics and water diffusion parameters of the Canarium schweinfurthii (CS) shellnut. This work is part of a vast project to valorize the above-mentioned cores for possible industrial use as charges in composites or abrasives materials. The study was based on the characterization of intrinsic physical characteristics of the coreshells scanning electron microscopic (SEM) observations desorption, adsorption and absorption kinetics. The water diffusion phenomenon was modeled and it appears that the Page model well predicted the kinetic of drying, absorption and adsorption. The effective diffusion coefficient and the energy of activation were calculated at three isothermal temperatures (50<span style="white-space:nowrap;">°</span>C, 70<span style="white-space:nowrap;">°</span>C and 90<span style="white-space:nowrap;">°</span>C). There was a tendency for hysteresis in the sorption-desorption cycles. These results strongly predicted the possibility of using these products as a filler in composites, clay building materials and cement because of their high water diffusion stability on a macroscopic scale.
