Given severe health-hazardous effects of aflatoxin B1(AFB1) widely occurring in cereal grains and animal feeds,it is highly urgent to develop analytical methods for its rapid screening.In this work,we proposed a simpl...Given severe health-hazardous effects of aflatoxin B1(AFB1) widely occurring in cereal grains and animal feeds,it is highly urgent to develop analytical methods for its rapid screening.In this work,we proposed a simple and high-throughput method for the determination of AFB1 in millet and buckwheat samples using high performance thin layer chromatography(HPTLC) linked to fluorescence densitometry.The first step was to optimize the solid-liquid extraction for the crude clean-up of the samples.The QuEChERS(Quick,Easy,Cheap,Effective,Robust and Safe) extraction strategy was used and different solvent systems for their extraction efficiency of AFB1 from the samples were evaluated.Then,trichloromethane:ethyl acetate(7:3,V/V) was used as the mobile phase to realize the separation of the targeted compound from background noises on silica gel plates.Quantification was readily performed with densitometry in fluorescence mode.In order to fix the optimal excitation wavelength,spectra scanning ranging 250-400 nm was carried out,revealing that 364 nm light gave the highest signal.With the optimized optical system,high sensitivity to AFB1 was achieved,with a limit of detection(LOD) at 3 μg/kg.Apart from that,good linearity(0.999) was obtained within the range of 1-80 ng/band of AFB 1.To assess the analysis accuracy,2 levels of AFB 1(50 and100 μg/kg) were spiked into real grain samples.The obtained results showed that the recovery rates were within the range of 81.6%-114.0%.The proof-of-concept results of this work evidenced that HPTLC is a promising analytical tool for the screening of mycotoxin in difficult samples.展开更多
In this work, we report the construction of three-dimensional(3D) CdS nanosphere/graphene networks by a one-step hydrothermal self-assembly route. The 3D graphene networks not only enhance the light scattering, thanks...In this work, we report the construction of three-dimensional(3D) CdS nanosphere/graphene networks by a one-step hydrothermal self-assembly route. The 3D graphene networks not only enhance the light scattering, thanks to the interconnected 3D architecture, but also improve the crystallinity of deposited CdS nanospheres, and at the same time provide a direct electron pathway to quickly separate the photogenerated electron-hole pairs from CdS, which thus dramatically improve the photocatalytic activity.The optimized 3D CdS nanosphere/graphene networks with 2 wt% of graphene could produce molecular hydrogen at a rate of 2310 μmol gcatalyst^(-1) h^(-1) under visible-light illumination(λ > 400 nm).展开更多
基金supported by National Key Research and Development Program of China (2021YFF0601902)Shanxi Scholarship Council of China (2021-068)+1 种基金Opening Project of Key Laboratory of Detection for Mycotoxins, Ministry of Agriculture and Rural Affairs China (SWDSJC2021001)Shanxi Agricultural University High-Level Talent Project (2021XG013)。
文摘Given severe health-hazardous effects of aflatoxin B1(AFB1) widely occurring in cereal grains and animal feeds,it is highly urgent to develop analytical methods for its rapid screening.In this work,we proposed a simple and high-throughput method for the determination of AFB1 in millet and buckwheat samples using high performance thin layer chromatography(HPTLC) linked to fluorescence densitometry.The first step was to optimize the solid-liquid extraction for the crude clean-up of the samples.The QuEChERS(Quick,Easy,Cheap,Effective,Robust and Safe) extraction strategy was used and different solvent systems for their extraction efficiency of AFB1 from the samples were evaluated.Then,trichloromethane:ethyl acetate(7:3,V/V) was used as the mobile phase to realize the separation of the targeted compound from background noises on silica gel plates.Quantification was readily performed with densitometry in fluorescence mode.In order to fix the optimal excitation wavelength,spectra scanning ranging 250-400 nm was carried out,revealing that 364 nm light gave the highest signal.With the optimized optical system,high sensitivity to AFB1 was achieved,with a limit of detection(LOD) at 3 μg/kg.Apart from that,good linearity(0.999) was obtained within the range of 1-80 ng/band of AFB 1.To assess the analysis accuracy,2 levels of AFB 1(50 and100 μg/kg) were spiked into real grain samples.The obtained results showed that the recovery rates were within the range of 81.6%-114.0%.The proof-of-concept results of this work evidenced that HPTLC is a promising analytical tool for the screening of mycotoxin in difficult samples.
基金supported by the National Natural Science Foundation of China (no. 91545116 and U1510108)Pioneer ‘‘Hundred Talents Program’’ of CAS, Start-Up Grant of Institute of Coal Chemistry (2016SCXQT01)+3 种基金Singapore Agency for Science, Technology and Research (A*Star)Science and Engineering Research Council- Public Sector Funding (PSF): 1421200075Singapore Ministry of Education Academic Research Fund (AcRF) Tier 1: RG10/16 and RG111/15State Key Laboratory of Coal Conversion (J17-18-913-1, J15-16913)
文摘In this work, we report the construction of three-dimensional(3D) CdS nanosphere/graphene networks by a one-step hydrothermal self-assembly route. The 3D graphene networks not only enhance the light scattering, thanks to the interconnected 3D architecture, but also improve the crystallinity of deposited CdS nanospheres, and at the same time provide a direct electron pathway to quickly separate the photogenerated electron-hole pairs from CdS, which thus dramatically improve the photocatalytic activity.The optimized 3D CdS nanosphere/graphene networks with 2 wt% of graphene could produce molecular hydrogen at a rate of 2310 μmol gcatalyst^(-1) h^(-1) under visible-light illumination(λ > 400 nm).
