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Wang D.-Y.,Guangxi University for Nationalities | Zou H.-H.,Guangxi Normal University | Hu F.-L.,Yulin Normal University | Li Y.-J.,Zhongshan Quality Supervision and Inspection Institute of Agricultural Products
Inorganic Chemistry Communications | Year: 2012

Three new complexes, [Co 2(oba)(dbca)(H 2O) 2]·5(H 2O) (1) [Co 2(oba)(dbca)(H 2O) 2]·DMF(H 2O) (2) and [Co 6(oba) 6(pyr) 8]·2.5H 2O (3) (H 2oba = 4,4′-oxydibenzoic acid, H 2dbca = diphenic acid, py = pyridine, DMF = N,N-dimethyl formamide) have been synthesized and characterized by infrared spectrum, thermal gravimetric analysis, X-ray powder diffraction and X-ray single crystal diffraction. 3D network of 1 contains interesting water clusters between the layers. Complex 2 displays similar configuration of 1 except that the free DMF molecules occupy the channel which is formed by the host. Complex 3 shows the (2,5)-connection network by using the py as the solvent. The magnetic property of complex 1 is also presented. © 2012 Elsevier B.V.


Wang F.,South China Agricultural University | Wang H.,South China Agricultural University | Shen Y.-D.,South China Agricultural University | Li Y.-J.,South China Agricultural University | And 6 more authors.
Journal of Agricultural and Food Chemistry | Year: 2016

A new multianalyte immunoassay was designed to screen furaltadone metabolite 5-morpholinomethyl-3-amino-2-oxazolidone (AMOZ), malachite green (MG), and leucomalachite green (LMG) in aquatic products using a bispecific monoclonal antibody (BsMAb). Gradient drug mutagenesis methods were separately used to prepare an anti-3-nitrobenzaldehyde-derivatized AMOZ (3-NPAMOZ) hybridoma cell line that was hypoxanthine-guanine-phosphoribosyltransferase (HGRPT) deficient and an anti-LMG hybridoma cell line that was thymidine kinase (TK) deficient. BsMAb recognizing 3-NPAMOZ and LMG was generated using hybrid-hybridomas of HGRPT and TK deficient cell lines. For AMOZ and LMG, respectively, the BsMAb-based indirect competitive ELSIA (ic-ELISA) values of 1.7 ng/mL and 45.3 ng/mL and detection limits of 0.2 ng/mL and 4.8 ng/mL. To establish the ic-ELISA, 3-NPAMOZ derivatized from AMOZ with 3-nitrobenzaldehyde and LMG reduced from MG by potassium borohydride was recognized by BsMAb. Recoveries of AMOZ, MG, and LMG in aquatic products were satisfactory and correlated with HPLC analysis. Thus, the multianalyte ic-ELISA is suitable for rapid quantification of AMOZ, MG, and LMG in aquatic products. © 2016 American Chemical Society.


Rao M.F.,South China Agricultural University | Li Y.J.,Zhongshan Quality Supervision and Inspection Institute of Agricultural Products | Dong J.X.,University of California at Davis | Wu W.J.,South China Agricultural University | And 3 more authors.
Analytical Methods | Year: 2016

A broad-specificity, single-chain antigen-binding fragment (scFab) for the detection of O,O-diethyl organophosphorus pesticides (DPPs) was produced and characterized. A recombinant plasmid encoding an Fab with broad specificity towards a specific class of DPPs was used as a template for amplification of the antibody heavy (Fd) and light (κ) chain genes, which were then cloned in two different orientations with the (Gly4Ser)3 linker. SDS-PAGE and western blotting were used to identify expression of the scFabs. Indirect competitive ELISA (icELISA) was used to test the immunology activity of two different κ/Fd orientations. The optimal scFab orientation was determined by characterizing the expression, specificity, and stability in comparison with their homologous scFv and Fab. The 50% inhibition of binding (IC50) values of the κ-linker-Fd scFab for coumaphos and parathion determined by icELISA were ∼1.5 ng mL-1 and 3.1 ng mL-1, respectively, surpassing that of the reverse scFab orientation, Fd-linker-κ (3.7 μg mL-1 and 8.5 μg mL-1, respectively). The IC50 of the κ-linker-Fd scFab was also similar to that of Fab and was relatively low in comparison with that of scFv. The concentration of scFab in the expression extract against the antigen was consistent with that of scFv, while Fab displayed a lower concentration in comparison with both scFv and scFab. After incubation for 9 days, scFab and Fab still exhibited high antigen-binding activity while scFv showed almost no remaining affinity. Analysis of DPP-spiked vegetable samples demonstrated that scFab-based detection using icELISA and gas chromatography by the QuEChERS approach yielded good sensitivity and reproducibility for monitoring food safety. © The Royal Society of Chemistry 2016.


Hu F.-L.,Yulin Normal University | Yang X.,Huaihua College | Li Y.-J.,Zhongshan Quality Supervision and Inspection Institute of Agricultural Products
Journal of Coordination Chemistry | Year: 2012

In this article, two copper(II) complexes, [Cu(2,2′-bpy) 2(ppac)](H2O)7 (1) and [Cu2(2, 2′-bpy)4(ppac)](HCO2̄)2(H 2O)16 (2), have been synthesized (H2ppac=p- phenylenediacetic acid, 2,2′-bpy=2,2′-bipyridine). We report structural evidence of discrete water clusters in the solid state. An unusual 1-D water tape notated T4(2)6(2) is present in complex 1. Complex 2 displays a hydrogen-bonded pillar-layered structure that is constituted by lattice waters. An unprecedented water cluster notated as T4(1)6(1)6(2) is present in complex 2. The units act as supramolecular glue in the aggregation of copper(II) complexes to give a 3-D cage-like network through hydrogen bonds. Preliminary investigation on electrochemical properties of the complexes is presented. © 2012 Taylor & Francis.


Luo L.,South China Agricultural University | Xu Z.-L.,South China Agricultural University | Yang J.-Y.,South China Agricultural University | Xiao Z.-L.,South China Agricultural University | And 6 more authors.
Journal of Agricultural and Food Chemistry | Year: 2014

Novel haptens were designed and synthesized to prepare antibodies against free histamine, but none resulted in producing suitable antibodies for developing an enzyme-linked immunosorbent assay (ELISA). However, an antiserum was obtained having high specificity and affinity to p-nitrobenzoylated histamine (NPHA), which can be easily formed from reaction between histamine and p-nitrobenzoic acid N-hydroxysuccinimide ester (PNBA-OSu) under mild conditions. Based on rabbit polyclonal antibodies, a competitive indirect ELISA (ciELISA) for histamine determination in foods was developed. After ciELISA and derivatization optimization, the assay showed good sensitivity, with limits of detection of 1.8 mg/kg, 93.6 μg/L, and 93.6 μg/kg in fish, red wine, and yoghurt, respectively, with negligible cross-reactivity with related biogenic amines and amino acids. Average recovery of histamine in fortified food samples ranged from 80.9% to 110.1% with coefficients of variation below 16.3%. Good correlation between the ciELISA and liquid chromatography-tandem mass spectrometry was obtained for spiked food samples. © 2014 American Chemical Society.


Luo L.,South China Agricultural University | Yang J.-Y.,South China Agricultural University | Xiao Z.-L.,South China Agricultural University | Zeng D.-P.,Guangzhou Wanlian Biotechnologies Co. | And 7 more authors.
RSC Advances | Year: 2015

Histamine (HA) is an essential test item for fishery samples. However, the fast and effective determination of HA is difficult due to its simple structure and small molecular size. In this study, a sensitive and specific monoclonal antibody against p-nitrobenzoylated histamine (NPHA), which can be easily obtained from the reaction of HA and p-nitrobenzoic acid N-hydroxysuccinimide ester (PNBA-OSu) under mild conditions, was generated for the first time. Based on this mAb, an immunochromato-graphic assay strip (ICA strip) using a colloidal gold nano particles-antibody (GNPs) probe for rapid detection of HA in saury samples was established. After screening the coating antigens and optimization of analytical parameters, a heterologous coating based ICA strip exhibited the most excellent detection ability with a visual detection limit (VDL) of 6.0 mg kg-1 in qualitative experiments and a detection limit (by a strip reader) of 1.0 mg kg-1 in semi-quantitative experiments for saury samples, with no cross-reactivity with HA analogs. Good correlation between the ICA strip with liquid chromatography-tandem mass spectrometry was achieved for spiked and naturally contaminated saury samples. Overall, this method is suitable for screening of HA residue for large scale fish samples in a quick, simple and low-cost manner. This journal is © The Royal Society of Chemistry.


Qin J.,South China Agricultural University | Shu Y.,South China Agricultural University | Li Y.,Zhongshan Quality Supervision and Inspection Institute of Agricultural Products | He H.,South China Agricultural University | Li H.,South China Agricultural University
Environmental Science and Pollution Research | Year: 2016

Perchlorate (ClO4 −) pollution is widespread in the natural environment, but the effects of ClO4 − on the terrestrial insects are rarely studied. Here, when phytophagous insect Spodoptera litura larvae were fed on the diets with different ClO4 − concentrations, changes in their life-history traits were recorded; ClO4 − accumulations in feces and insect body were detected. The results demonstrated that ClO4 − bioaccumulation in insect at the different developmental stages was ranked in the order: adults > pupae > the 4th > 5th > 6th instar larvae. Besides, ClO4 − accumulations in the feces were ranked in the order: the 6th > 5th > 4th instar larvae. The ClO4 − accumulations in female pupae and adults were significantly higher than that in males. ClO4 − bioaccumulation in insect prolonged larval development time and caused a skewed sex ratio (the percentage of males at metamorphosis significantly decreased) under 100 to 200 mg ClO4 −/kg treatment. Therefore, ClO4 − accumulations in S. litura body presented developmental stage-, sex-specific pattern, and the sex-specific ClO4 − accumulations resulted in difference of sex ratio. These effects were observed at concentrations reported in natural environments contaminated with ClO4 −, suggesting that this contaminant may pose a threat to the normal development and growth of this insect species. © 2016 Springer-Verlag Berlin Heidelberg


PubMed | University of Salford, South China Agricultural University and Zhongshan Quality Supervision and Inspection Institute of Agricultural Products
Type: | Journal: Chemosphere | Year: 2016

In a previous piece of work, we reported some preliminary experimental results showing that hydrogen peroxide at a concentration range frequently encountered in rainwater could lead to degradation of three common herbicides (diuron, butachlor and glyphosate). However, the work was limited to the observation on the effects of Fenton process on the individual herbicides. In field conditions, different types of herbicides along with other organic molecules may occur concurrently. It is unclear how different herbicides and various organic molecules compete for the available hydroxyl radical. In this study, further laboratory experiments were conducted to observe the changes in the herbicides in the scenarios where multiple herbicides or humic acid are present. The results show that humic acid impeded hydroxyl radical-driven degradation of the diuron and butachlor. However, humic acid had no significant effects on reducing glyphosate removal rate. Glyphosate could compete strongly with the humic acid for the available hydroxyl radical in the reaction systems. The reactivity of glyphosate with hydroxyl radical was much higher than those of diuron and butachlor due possibly to its relatively simpler chemical structure, as compared to either diuron or butachlor, which are aromatic compounds that have higher chemical stability. Butachlor degradation was much weaker in the combined diuron and butachlor system than in the combined glyphosate and butachlor system. In the glyphosate-butachlor system, the opposite was observed. The findings have moved another step forward to understanding the potential role of rainwater-borne H


PubMed | South China Agricultural University and Zhongshan Quality Supervision and Inspection Institute of Agricultural Products
Type: Journal Article | Journal: Environmental science and pollution research international | Year: 2016

Perchlorate (ClO4 (-)) pollution is widespread in the natural environment, but the effects of ClO4 (-) on the terrestrial insects are rarely studied. Here, when phytophagous insect Spodoptera litura larvae were fed on the diets with different ClO4 (-) concentrations, changes in their life-history traits were recorded; ClO4 (-) accumulations in feces and insect body were detected. The results demonstrated that ClO4 (-) bioaccumulation in insect at the different developmental stages was ranked in the order: adults > pupae > the 4th > 5th > 6th instar larvae. Besides, ClO4 (-) accumulations in the feces were ranked in the order: the 6th > 5th > 4th instar larvae. The ClO4 (-) accumulations in female pupae and adults were significantly higher than that in males. ClO4 (-) bioaccumulation in insect prolonged larval development time and caused a skewed sex ratio (the percentage of males at metamorphosis significantly decreased) under 100 to 200mg ClO4 (-)/kg treatment. Therefore, ClO4 (-) accumulations in S. litura body presented developmental stage-, sex-specific pattern, and the sex-specific ClO4 (-) accumulations resulted in difference of sex ratio. These effects were observed at concentrations reported in natural environments contaminated with ClO4 (-), suggesting that this contaminant may pose a threat to the normal development and growth of this insect species.

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