Beijing Research Center for Agricultural Standards and Testing

Beijing, China

Beijing Research Center for Agricultural Standards and Testing

Beijing, China
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Wang M.,Beijing Research Center for Agricultural Standards and Testing | Wang M.,Risk Assessment Laboratory for Agro products Beijing | Jiang N.,Beijing Research Center for Agricultural Standards and Testing | Jiang N.,Risk Assessment Laboratory for Agro products Beijing | And 6 more authors.
Journal of Agricultural and Food Chemistry | Year: 2017

Early and late ripening sweet cherries were characterized for phenolic acids, and also their antioxidant capacity and potential antifungal effects were investigated. Free, conjugated, and bound phenolics were identified and quantified using ultra performance liquid chromatography-tandem mass spectrometry. Our results indicated that the early ripening cultivars contained higher free phenolic acids, which was positively related to remarkable antioxidant properties and the inhibition effects on Alternaria alternata and tenuazonic acid (TeA) accumulation. However, conjugated phenolics of the late ripening cultivars, mainly including caffeic, 2,3,4-trihydroxybenzoic, p-coumaric, and pyrocatechuic acids, achieved the highest antifungal effects and almost completely inhibited the A. alternata and TeA production. 2,2-Diphenyl-1-picrylhydrazyl testing and ferric ion reducing antioxidant power assay showed strong positive correlation with total phenolics and specific phenolics such as free epicatechin and conjugated 2,3,4-trihydroxybenzoic acids and also with antifungal activity. Results from this study provide further insights into the health-promoting phenolic compounds in sweet cherries. © 2017 American Chemical Society.


PubMed | Yantai Academy of Agricultural science, China Institute of Technology, Chinese Academy of Agricultural Sciences, Beijing Research Center for Agricultural Standards and Testing and Northwest Agriculture and Forestry University
Type: | Journal: Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association | Year: 2016

In the present study, the long-term and short-term cumulative risks of pyrethroids exposured for the Chinese general population and children through fruits consumption were evaluated. A total of 1450 fruit samples and seven pyrethroids were included based on the pesticide residues monitoring programme of China from 2013 to 2015. The exposure was estimated using both deterministic approach and semi-probabilistic model for comparison. The hazard index approach was used to assess cumulative risk. 26% of samples contained pyrethroid residues with concentrations ranged from 0.0050mg/kg to 1.2mg/kg, of which 30% simultaneously with 2-4 mixture residues. Results demonstrated that the cumulative health risks were extremely low for both general population and children (1-6 years old) of China in the long term. Acute risk estimations calculated by deterministic method were several or many times overestimated than the results based on semi-probabilistic method. Acute cumulative exposure of children to pyrethroid compounds in 0.76% samples were exceeded 1 in worst case scenario. More detailed assessments with adequate data in the future use probabilistic method is expected to reduce the uncertainties of cumulative dietary exposure.


Han P.,Beijing Research Center for Agricultural Standards and Testing | Han P.,China Agricultural University | Feng X.Y.,Beijing Research Center for Agricultural Standards and Testing | Wang J.H.,Beijing Research Center for Agricultural Standards and Testing
Advanced Materials Research | Year: 2014

Concentration of 7 heavy metals in 269 topsoil samples were determined which collected from Shilou town of Fangshan district in Beijing, and the data was analyzed by the single factor index and the Nemerow index for the soil environment quality evaluation. The mean values of the heavy metals were 8.24 ± 1.42, 0.209 ± 0.07, 62.99 ±8.89, 0.133 ± 0.11, 25.29 ± 5.02, 23.91 ± 5.72 and 86.29 ± 28.13 mg kg-1 for As, Cd, Cr, Hg, Cu, Pb, and Zn, respectively. Average concentration of As, Cd, Cr, Cu and Zn exceeded the background value of Beijing area. It was found that all heavy metals were not in normal distribution. The soil environment quality was evaluated by single factor pollution index and Nemerow index of heavy metals. The order of single factor index was Cd, Zn, Hg, Cu, Cr, Pb, As in decreasing. Average Nemerow index of soil was 0.918. This value was reached to the grade III standard of soil environmental quality assessment classification. © (2014) Trans Tech Publications, Switzerland.


Liu D.,China Agricultural University | Min S.,China Agricultural University | Ping H.,Beijing Research Center for Agricultural Standards and Testing | Song X.,China Agricultural University
Journal of Chromatography A | Year: 2016

A simple and rapid method was developed for evaluating 16 phthalic acid esters (PAEs) at the μg/kg level in a complex milk matrix using directly suspended droplet microextraction-gas chromatography mass spectrometry (DSDME-GC-MS). The different parameters for extraction and for the DSDME experiment were optimized, including You are free to submit the revised manuscript at a later date as a new submission.10. g/L trichloroacetic acid concentration, 100. μL cyclohexane micro-droplet organic solvent, 1100. rpm stirring speed, 10. min extraction time and no salt amount. Validation experiments showed good linearity (γ. > 0.9878, 0.002-0.4. μg/mL), satisfactory precision (RSD. <. 11%), and good accuracy (relative recovery of 70.2-108%) when analyzing milk samples using the optimized method. The limits of detection (LODs) ranged between 0.001 and 0.2. μg/L, and the limits of quantification (LOQs) ranged between 0.003 and 0.7. μg/L for 15 PAEs. Dinonyl phthalate (DINP) had a low response and did not have good linearity. The proposed method was successfully applied for the analysis of PAEs in real milk samples. © 2016 Elsevier B.V.


PubMed | Chinese Institute for the Control of Agrochemicals, Beijing Research Center for Agricultural Standards and Testing and Beijing Academy of Agriculture and Forestry Sciences
Type: Journal Article | Journal: Journal of separation science | Year: 2016

A rapid, selective and sensitive sample preparation method based on solid-phase extraction combined with the dispersive liquid-liquid microextration was developed for the determination of pyrethroid pesticides in wheat and maize samples. Initially, the samples were extracted with acetonitrile and water solution followed phase separation with the salt addition. The following sample preparation involves a solid-phase extraction and dispersive liquid-liquid microextraction step, which effectively provide cleanup and enrichment effects. The main experimental factors affecting the performance both of solid-phase extraction and dispersive liquid-liquid microextration were investigated. The validation results indicated the suitability of the proposed method for routine analyze of pyrethroid pesticides in wheat and maize samples. The fortified recoveries at three levels ranged between 76.4 and 109.8% with relative standard deviations of less than 10.7%. The limit of quantification of the proposed method was below 0.0125 mg/kg for the pyrethoroid pesticides. The proposed method was successfully used for the rapid determination of pyrethroid residues in real wheat and maize samples from crop field in Beijing, China.


Chen Z.,Capital Normal University | Tan L.,Capital Normal University | Hu L.,Capital Normal University | Luan Y.,Beijing Research Center for Agricultural Standards and Testing
Talanta | Year: 2015

Here, a simple, and highly sensitive fluorescent assay is designed to monitor K+. The versatile, robust biosensing strategy is based on the specific recognition utility of label-free aptamers with their targets and PicoGreen dye as the signal probe. The aptamers undergo a conformational change to a secondary structure such as G-quadruplex in the presence of targets. In addition to a conformational change with its targets, the remaining single-stranded DNA (ssDNA) aptamer form a duplex structure with its complete complementary sequence. Conformational changes of aptamers as well as fluorescence amplification produce clear signal-off in the presence of targets. Fluorescent assay employing this mechanism for the detection of K+ is highly sensitive, and selective. The detection limit of the K+ assay is determined to be 2.37 pM. The sensing strategy is low-cost and simple in its operation without requirement for complex labeling of probe DNA or sophisticated synthesis of the fluorescent compound. Also, the method has less structural requirement of complexes of aptamers with their targets, thus rending its wilder applications for various targets. © 2015 Elsevier B.V. All rights reserved.


Li C.,Beijing Research Center for Agricultural Standards and Testing | Lu A.,Beijing Research Center for Agricultural Standards and Testing | Lu A.,Collaborative Innovation Center for Key Technology of Smart Irrigation District in Hubei | Wang J.,Beijing Research Center for Agricultural Standards and Testing | And 5 more authors.
Journal of Separation Science | Year: 2014

A fast and novel analytical method was developed for the determination of trace levels of sulfonylurea herbicides in water and soil samples. Graphene was used as a sorbent for extraction, and ultra high performance liquid chromatography with tandem mass spectrometry was used for quantification. Five sulfonylurea herbicides were preconcentrated from water samples using a graphene-loaded packed cartridge, while extraction from soil samples was performed in a single step using graphene-supported matrix solid-phase dispersion. Under the optimized conditions, the calibration plots were linear in the range between 5 and 1000 ng/L for water samples, and between 1 and 200 ng/g for soil samples. All correlation coefficients (R) were >0.99. The limits of detection for water and soil samples were 0.28-0.53 ng/L and 0.08-0.26 ng/g, respectively. This method was successfully applied to the analysis of spiked samples of environmental water and soil, with recoveries ranging from 84.2-109.3 and 86.12-103.2%, respectively, all with relative standard deviations of <10%. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


PubMed | Beijing Research Center for Agricultural Standards and Testing
Type: Journal Article | Journal: Journal of separation science | Year: 2014

A fast and novel analytical method was developed for the determination of trace levels of sulfonylurea herbicides in water and soil samples. Graphene was used as a sorbent for extraction, and ultra high performance liquid chromatography with tandem mass spectrometry was used for quantification. Five sulfonylurea herbicides were preconcentrated from water samples using a graphene-loaded packed cartridge, while extraction from soil samples was performed in a single step using graphene-supported matrix solid-phase dispersion. Under the optimized conditions, the calibration plots were linear in the range between 5 and 1000 ng/L for water samples, and between 1 and 200 ng/g for soil samples. All correlation coefficients (R) were >0.99. The limits of detection for water and soil samples were 0.28-0.53 ng/L and 0.08-0.26 ng/g, respectively. This method was successfully applied to the analysis of spiked samples of environmental water and soil, with recoveries ranging from 84.2-109.3 and 86.12-103.2%, respectively, all with relative standard deviations of <10%.


PubMed | Beijing Research Center for Agricultural Standards and Testing and Capital Normal University
Type: | Journal: Talanta | Year: 2015

Here, a simple, and highly sensitive fluorescent assay is designed to monitor K(+). The versatile, robust biosensing strategy is based on the specific recognition utility of label-free aptamers with their targets and PicoGreen dye as the signal probe. The aptamers undergo a conformational change to a secondary structure such as G-quadruplex in the presence of targets. In addition to a conformational change with its targets, the remaining single-stranded DNA (ssDNA) aptamer form a duplex structure with its complete complementary sequence. Conformational changes of aptamers as well as fluorescence amplification produce clear signal-off in the presence of targets. Fluorescent assay employing this mechanism for the detection of K(+) is highly sensitive, and selective. The detection limit of the K(+) assay is determined to be 2.37 pM. The sensing strategy is low-cost and simple in its operation without requirement for complex labeling of probe DNA or sophisticated synthesis of the fluorescent compound. Also, the method has less structural requirement of complexes of aptamers with their targets, thus rending its wilder applications for various targets.


PubMed | Beijing Research Center for Agricultural Standards and Testing and Beijing Academy of Agricultural and Forestry science
Type: | Journal: Journal of chromatography. A | Year: 2016

A simple and rapid extraction procedure for the simultaneous determination of eight mycotoxins (Alternaria toxins, ochratoxin A, patulin, citrinin) in a variety of fruit matrices has been developed using ultra high performance liquid chromatography coupled to tandem mass spectrometry. The procedure involves a one-step cleanup using homemade solid phase extraction (SPE) cartridges. By comparative evaluation among six various adsorbents (C18, PSA, HLB, MCX, Silica, NH2), the combination of MCX and NH2 was found to provide the most effective cleanup, removing the greatest number of matrix interferences and also allowing the quantification of all analyzed mycotoxins in fruits. The optimized extraction conditions including acidified aqueous acetonitrile and an additional salt-out step using NaCl were employed before SPE cleanup. Method validation was performed by analyzing samples spiked at three levels (LOQ, 2 LOQ and 10 LOQ). Four fruits including apple, sweet cherry, tomato and orange fruits were selected, and accuracy (recovery%), precision (RSD%), limits of quantification (LOQ), linearity and matrix effect were evaluated during validation. Matrix-matched linearity with correlation coefficients 0.9921 was established in the range of 5-200 ng mL(-1) for patulin and 1-200 ng mL(-1) for other mycotoxins, respectively. Recoveries between 74.2% and 102.4% and relative standard deviations lower than 4.7% were obtained for all tested fruits. The matrix effect observed was low ( 17%) in all three fruit matrixes with the exception of orange, for which strong ion suppression was observed for alternariol (25.3%), ochratoxin A (31.6%) and citrinin (40.3%). Therefore, matrix-matched calibration was used for a correct quantification in order to compensate for matrix effect. The limits of quantification (LOQ), ranging from 1 to 5 g kg(-1) depending on mycotoxins type, were always lower than maximum permitted levels for every regulated mycotoxin by the current European legislation.

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