Chongqing Entry Exit Inspection and Quarantine Bureau

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Chongqing Entry Exit Inspection and Quarantine Bureau

Chongqing, China

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Qian S.,Southwest University | Zhu H.,Southwest University | Xiong B.,Southwest University | Xiong B.,Zunyi Normal College | And 4 more authors.
Environmental Science and Pollution Research | Year: 2017

Endosulfan is an organochlorine pesticide widely used in Southwest China. In this paper, the adsorption and desorption characteristics of endosulfan in two typical agricultural soils (latosol and lateritic red soil) in this area were studied. The results showed that Langmuir isothermal equation could well describe the adsorption thermodynamic characteristics of endosulfan in latosol and lateritic red soil, and the maximum adsorption capacities of α-endosulfan were 0.186 and 0.209 mg/g, while those of β-endosulfan were 0.140 and 0.148 mg/g, respectively. Endosulfan adsorption in the two soils was an exothermic physicochemical process, but dominated by physical process. The adsorption kinetic characteristics of endosulfan in the two soils could be well described by second-order kinetic equation, and the initial rate constants were 0.228 and 0.325 mg/(g min) for α-endosulfan, while those were 0.119 and 0.125 mg/(g min) for β-endosulfan, respectively. The adsorbed endosulfan in the two soils was difficult to be desorbed into the liquid phase, and showed weak desorption hysteresis. These results implied that endosulfan could be firmly adsorbed by the two soils, and their adsorption and desorption abilities may be related to the contents of soil clay and organic matter. © 2017 Springer-Verlag Berlin Heidelberg


Xie J.,University of South China | Peng T.,Chinese Academy of Inspection and Quarantine | Chen D.-D.,Chinese Academy of Inspection and Quarantine | Zhang Q.-J.,University of South China | And 6 more authors.
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences | Year: 2013

A high performance liquid chromatography method with visible detection (HPLC-VIS) for the determination of malachite green (MG), crystal violet (CV), leucomalachite green (LMG), and leucocrystal violet (LCV) in fish has been developed after clean-up through an immunoaffinity column (IAC). Residues were simultaneously extracted from fish muscle with acetonitrile and ammonium acetate buffer. The leuco-forms, LMG and LCV, were oxidized quantitatively to the chromic CV and MG by reaction with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone. Extracts were then purified on an IAC which prepared by immobilizing the anti-MG-CV antibodies by the sol-gel method. Finally, the eluents were analyzed by HPLC-VIS. The limits of detection were 0.15, 0.1, 0.18 and 0.14. ng/g for MG, CV, LMG and LCV, respectively. The average recoveries in samples fortified with MG, CV, LMG and LCV over the range 0.5-10. ng/g were from 71.6% to 96.8% with RSDs of 5.1-12.3% (n=6). This novel method was confirmed by liquid chromatography-tandem mass spectrometry with electrospray interface in positive mode using multiple reaction monitoring. © 2012 Elsevier B.V.


Peng T.,Chinese Academy of Inspection and Quarantine | Zhu A.-L.,China Agricultural University | Zhou Y.-N.,CAS Institute of Chemistry | Hu T.,China Agricultural University | And 7 more authors.
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences | Year: 2013

A multi-residue analysis method for simultaneous determination of nine subclasses of non-steroidal anti-inflammatory drugs (NSAIDs) in milk and dairy products by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) has been established. The sample was initially extracted and deproteinized with ascorbic acid buffer (0.01. M, pH 3) and acetonitrile-ethyl acetate mixture, followed by centrifugation and evaporation, then reconstituted with acetonitrile-0.1% formic acid (1. +. 1, v/v). After removal of lipid material by n-hexane, the sample was analyzed by UPLC-MS/MS with electro-spray ionization (ESI) interface in Multiple Reaction Monitoring (MRM) mode. The range of limits of detection (LODs) and limits of quantification (LOQs) were 0.03-0.30. μg/kg and 0.10-1.00. μg/kg, respectively. The recoveries in milk, milk powder, yogurt, processed cheese and milk beverage ranged from 61.7% to 117%, and the relative standard deviations (RSDs) were less than 17.9% at three spiked levels (1, 10 and 100 times of the LOQ). Matrix effects were also investigated and it was determined the signals of the analytes were suppressed from 9.4% to 76.6% in processed cheese. The proposed method was also applied to incurred sample analysis. The results proved that this method was suitable for the simultaneous determination of nine subclasses of NSAIDs residues in milk and dairy products. © 2013 Elsevier B.V.


Zhang Q.-J.,University of South China | Peng T.,Chinese Academy of Inspection and Quarantine | Chen D.-D.,Chinese Academy of Inspection and Quarantine | Xie J.,University of South China | And 3 more authors.
Journal of AOAC International | Year: 2013

A method based on HPLC with UV detection was developed for the quantitative determination of chloramphenicol (CAP) residues in aquatic products. The samples were extracted with ethyl acetate-ammonium hydroxide (98 + 2, v/v), followed by a cleanup step using an immunoaffinity column. The analytes were determined by HPLC-UV. Optimal conditions for the extraction and cleanup procedures are described. The linear regression equation was y = 91.47× - 8.60 with R2 = 0.9998 (y = peak area and × = CAP concentration) and showed a good reproducibility. The LOQ was 0.25 μg/kg for determining CAP spiked in the aquatic products. The mean recoveries of CAP from fish and shrimp samples fortified at 0.25-1.0 μg/kg were 88.7-93.1 and 92.0-97.3%, respectively; the repeatability RSDs were less than 8.1%. It was concluded that the method is simple, highly sensitive, and low cost for quantitatively measuring CAP residues in aquatic products. Analyte identification was confirmed by HPLC/MS/MS analysis.


Hu T.,China Agricultural University | Peng T.,Chinese Academy of Inspection and Quarantine | Li X.-J.,Chinese Academy of Inspection and Quarantine | Chen D.-D.,Chinese Academy of Inspection and Quarantine | And 10 more authors.
Journal of Chromatography A | Year: 2012

An ultra-high-performance liquid chromatography with tandem mass spectrometric detection (UHPLC-MS/MS) method was established for the simultaneous determination of residues of thirty non-steroidal anti-inflammatory drugs (NSAIDs) in swine muscle. The samples were extracted with acetonitrile and phosphoric acid. The extracts were defatted with n-hexane, and then purified by HLB solid-phase extraction cartridge. Analysis was carried out on UHPLC-ESI-MS/MS working with multiple reaction monitoring mode with polarity switching. Limits of detection were between 0.4μg/kg and 2.0μg/kg, and limits of quantification were between 1.0μg/kg and 5.0μg/kg. The recoveries of NSAIDs were between 61.7% and 125.7% at spiked levels of 1.0-500μg/kg. The repeatability was less than 8% and the within-laboratory reproducibility was not more than 12.3%. The method was reliable, convenient and sensitive. © 2011 Elsevier B.V.


Peng L.-J.,Guizhou University | Sun T.,Chongqing Entry Exit Inspection and Quarantine Bureau | Yang Y.-L.,Liupanshui Normal University | Cai L.,CAS Institute of Microbiology | And 4 more authors.
Mycoscience | Year: 2013

Twenty-six strains representing three species of Colletotrichum were isolated from leaf and fruit lesions of vitaceous plants in Guizhou and Yunnan provinces, China. The strains were characterized by morphology and phylogenetic analyses of actin, β-tubulin, calmodulin, glutamine synthetase, glyceraldehyde-3-phosphate dehydrogenase and rDNA internal transcribed spacer gene sequences. The combined dataset showed that 20 of 26 strains represented a novel species, the rest being Colletotrichum fructicola (four strains) and Colletotrichum gloeosporioides (two strains). The new species is described herein as Colletotrichum viniferum. Its conidia, compared with similar Colletotrichum species are cylindrical and 12e 16 mm long. Based on pathogenicity tests, C. viniferum caused leaf spots and anthracnose of table grape but was not host-specific. © 2012 The Mycological Society of Japan. Published by Elsevier B.V. All rights reserved.


Cao S.,Southwest University | Zhang L.,Chongqing Entry Exit Inspection and Quarantine Bureau | Chai Y.,Southwest University | Yuan R.,Southwest University
Biosensors and Bioelectronics | Year: 2013

In this article, we used the TiO2-graphene-Pt-Pd hybrid nanocomposites (TGPHs) as an enhanced element of the integrated sensing platform for increasing the surface area as well as improving the electronic transmission rate. Subsequently, Au nanoparticles (AuNPS) and cholesterol oxidase (ChOx) were successively self-assembled to TGPHs with high load amount and superior biological activity. The morphology of TGPHs and stepwise fabrication processes were characterized with cyclic voltammetry (CV), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Based on the efficiently catalytic ability of TGPHs and AuNPS, the fabricated biosensor exhibited wide linear ranges of responses to cholesterol in the concentration ranges of 5.0×10-8-5.9×10-4M, the limit of detection was 0.017μM (S/N=3). The response time was less than 7s and the Michaelis-Menten constant (Kmapp))was found as 0.21mM. The fabricated biosensor was further tested using real food samples egg, meat, margarine and fish oil, showing that the biosensor has the potential to be used as a facile cholesterol detection tool in food and supplement quality control. © 2012 Elsevier B.V.


Cao S.,Southwest University | Zhang L.,Chongqing Entry Exit Inspection and Quarantine Bureau | Chai Y.,Southwest University | Yuan R.,Southwest University
Talanta | Year: 2013

A new electrochemical biosensor with enhanced sensitivity was developed for detection of cholesterol by using platinum-palladium-chitosan-grapheme hybrid nanocomposites (PtPd-CS-GS) functionalized glassy carbon electrode (GCE). An electrodeposition method was applied to form PtPd nanoparticles-doped chitosan-grapheme hybrid nanocomposites (PtPd-CS-GS), which were characterized by scanning electron microscopy (SEM) and electrochemical methods. The presence of the PtPd-CS-GS nanocomposites not only accelerated direct electron transfer from the redox enzyme to the electrode surface, but also enhanced the immobilized amount of cholesteroloxidase (ChOx). Under optimal conditions, the fabricated biosensor exhibited wide linear ranges of responses to cholesterol in the concentration ranges of 2.2×10-6 to 5.2×10 -4 M, the limit of detection was 0.75 μM (S/N=3). The response time was less than 7 s and the Michaelis-Mentenconstant (Km app) was found as 0.11 mM. In addition, the biosensor also exhibited excellent reproducibility and stability. Along with these attractive features, the biosensor also displayed very high specificity to cholesterol with complete elimination of interference from UA, AA, and glucose. © 2013 Elsevier B.V. All rights reserved.


Yin Y.,CAS Research Center for Eco Environmental Sciences | Liu Y.,Chongqing Entry Exit Inspection and Quarantine Bureau | Liu J.,CAS Research Center for Eco Environmental Sciences | He B.,CAS Research Center for Eco Environmental Sciences | Jiang G.,CAS Research Center for Eco Environmental Sciences
Analytical Methods | Year: 2012

Volatile species generation-flameless/flame atomization-atomic fluorescence spectrometry (VSG-FL/FA-AFS) without chromatographic separation was developed for quantitative determination of inorganic mercury (IHg) and methylmercury (MeHg) in water and biological samples by using a commercially available atomic fluorescence spectrometer. In the proposed method, inorganic mercury was measured by using the flameless mode. However, by using the flame atomization mode, the volatile hydride of MeHg generated by KBH 4 can be transformed to elemental mercury vapour in the reductive argon-hydrogen flame, and both MeHg and IHg give a fluorescence signal in this flame atomization mode. Then, the concentration of MeHg can be calculated by subtracting IHg concentration from the total mercury concentration. The limits of detection for IHg and MeHg were 0.03 μg L -1 and 0.05 μg L -1, respectively. Spiked environmental water samples including seawater, tap water and river water were determined and satisfactory recoveries were obtained for MeHg and IHg. Furthermore, the proposed method was successfully applied to analyze biological certified reference material, TORT-2 (lobster hepatopancreas). © 2012 The Royal Society of Chemistry.


Cao S.,Chongqing Entry Exit Inspection and Quarantine Bureau | Wang J.,Chongqing Medical University | Zhang L.,Chongqing Entry Exit Inspection and Quarantine Bureau | Li X.,Chongqing Entry Exit Inspection and Quarantine Bureau | And 2 more authors.
Analytical Letters | Year: 2014

A simple and efficient gas chromatography method for the determination of 27 organochlorine and pyrethroid pesticides in traditional Chinese medicine was developed. Pesticide residues were extracted from the samples by oscillation and ultrasound, and purified by gel permeation chromatography and florisil solid phase extraction. The analysis was performed by gas chromatography with micro-electron capture detection. The purification conditions, such as the extraction and elution solvents, extraction methodology, and gel permeation chromatography conditions, were optimized. Traditional Chinese medicines were purified by different methods based on their composition. Under optimized conditions, the calibration graph was linear from 10 to 500 μg/L and the correlation coefficients varied from 0.9958 to 0.9997. The detection limits of these pesticides were between 0.09 and 1.82 μg/kg. The recovery of the pesticides spiked in various samples at four concentrations ranged from 73.2% to 106.4%, with relative standard deviations between 1.0% and 14.0%. This study indicates that the method is useful for determining pesticides in rhizome traditional Chinese medicines. © 2014 Copyright Taylor and Francis Group, LLC.

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