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Mou Y.,Shanghai Ocean University | Guo D.,Shanghai Exit Entry Inspection and Quarantine Bureau | Ding Z.,Shanghai Ocean University
Se pu = Chinese journal of chromatography / Zhongguo hua xue hui | Year: 2013

A high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed for the determination of the plant growth regulator (PGR) (paclobutrazol, forchlorfenuron, isopentennyladenine and 6-benzylaminopurine) residues in amphisarcas. The sample was extracted with acetonitrile, then cleaned up by MCX solid phase extraction. The HPLC separation was performed on an Agilent XDB-C18 column with 5 mmol/L ammonium acetate solution and acetonitrile containing 0.1% (volume percentage) formic acid as the mobile phases in a gradient elution mode. The PGRs were determined by MS/MS in positive electrospray ionization mode, and quantified by matrix-matched external standard method. The calibration curves showed good linearity in each range with correlation coefficients greater than 0.999. The limits of quantification (LOQs, S/N > 10) were 0.04-1.35 g/kg and the limits of detection (LODs, S/N > 3) were 0. 01-0 41 microg/kg for the four PGRs spiked in cucumber and apple. The recoveries of the four PGRs spiked at three levels ranged from 81.0% to 93.%, with the relative standard deviations (RSDs) of 3.5%-9.5%. The sensitivity, accuracy and precision of the method meet the technical standards of the pesticide determination. Therefore the method can be applied to the determination of the four PGRs in amphisarcas. Source


Fang X.,Shanghai Exit Entry Inspection and Quarantine Bureau | Zhang X.,Shanghai Ocean University | Feng C.,Shanghai Ocean University | Tang Y.,Shanghai Exit Entry Inspection and Quarantine Bureau | Ding Z.,Shanghai Ocean University
Journal of the Chinese Cereals and Oils Association | Year: 2015

The synchronous fluorescence spectra including 20 categories of edible vegetable oils as well as adulterated extra virgin olive oils were collected by Synchronous Fluorescence Spectrometry (SFS). The spectra were acquired by varying the excitation wavelength within 250-720 nm with the wavelength interval (Δλ) of 15 nm. On basis of analysis and comparison of the spectra of various vegetable oils, the SFS had revealed an obvious difference between the extra virgin olive oil and the other 17 categories of edible vegetable oils. In detection of olive oil adulteration, in cases which 14 categories of vegetable oil blending quantity in 1%, the spectra of adulterants could be discriminated from extra virgin olive oil. SFS for olive oil adulteration detection requires no complicated sample pretreatment. The method is simple, rapid and sensitive to be suitable for rapid screening detection of olive oil adulteration. ©, 2015, Editorial Department, Chinese Cereals and Oils Association. All right reserved. Source


Wang C.,Shanghai Exit Entry Inspection and Quarantine Bureau | Chu Q.,Shanghai Exit Entry Inspection and Quarantine Bureau | Chen C.,Nanjing Xiaozhuang University | Bo Z.,Nanjing Normal University
Spectroscopy | Year: 2011

Fluorescence spectroscopy, UV absorption, circular dichroism (CD) spectroscopy and molecular modeling methods were used to characterize the binding properties of thiacloprid (TL) with human serum albumin (HSA) at molecular level under physiological conditions. The fluorescence intensity of HSA decreased regularly with the gradually increasing concentration of thiacloprid. The binding constant K at three different temperatures (290, 300 and 310 K) were 3.07, 2.74 and 1.35×104 M-1, respectively, for TL-HSA interaction have been calculated from the relevant fluorescence data. CD spectroscopic measurements have shown that the secondary structures of the protein have been changed by the interaction of thiacloprid with HSA. Furthermore, the study of molecular modeling indicated that thiacloprid could be located on the surface of the binding pocket of subdomains IIA in HSA. The hydrophobic interaction was the major acting force and there are H-bonds and electrostatic interactions between TL and HSA, which is in good agreement with the results from the experimental thermodynamic parameters (the enthalpy change ΔH and the entropy change ΔS were calculated to be-20.378 kJ/mol and 16.328 J/mol K according to the Van't Hoff equation). © 2011 - IOS Press and the authors. All rights reserved. Source


Chuanxian W.,Shanghai Exit Entry Inspection and Quarantine Bureau | Fan H.,Shanghai Ocean University | Min W.,Shanghai Exit Entry Inspection and Quarantine Bureau | Yonggang S.,Shanghai Exit Entry Inspection and Quarantine Bureau | And 6 more authors.
Chinese Journal of Chromatography (Se Pu) | Year: 2013

A method was developed for simultaneousβualitative and quantitative analysis of five metabolites of nitrofuran antibiotics-, including 3-amino-2-oxazolidinone (AOZ), 5-morpho-lino-methyl-3-amino-2-oxazolidinoneβ (AMOZ), semicarbazide (SEM), 1-aminohydantoin (AHD) and 3,5-dinitrosalicylic acid hydrazide (DNSH) in aquatic products by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The samples were hydrolyzed with HC1, and derivatized with 2-nitrobenzaldehyde at 37 °C for 16 hours. The derivative solutions were adjusted to PH 7. 0-7.5, and the analytes were extracted by ethyl acetate. The separation was basedβon Thermo Aquasil Cl8 column (150 mm x4. 6 mm, 3. 0 pm). The analytes were detected by tandem mass spectrometry with electrospray ionization source with multiple reaction monitoring (MRM) mode. The developed method showed good linear correlation between the peak area ratios of the analyte and the internal standard and the concentration of the analyte with the correlation coefficients all above 0. 99 over the dynamic range of 0. 5 - 10 βg/kg. The limits of quantitation (LOQs) of AOZ, AMOZ, SEM, AHD and DNSH were 0.5 βg/kg. The average recoveries of all the compounds at four spiked levels of 0. 5, 1. 0, 2. 0 and 4. 0 μg/kg ranged from 81. 3o/o to 100. 5o/o with the RSDs between 3. 4% and 10. 0% (n=6). The method is proved to be fast and effective for simultaneous qualitative and quantitative analysis of the metabolites of the nitrofuran antibiotics in aquatic products. Source


Liu Q.,Sanda University | Han L.,Shanghai Exit Entry Inspection and Quarantine Bureau | Yi X.-H.,Shanghai Exit Entry Inspection and Quarantine Bureau | Shi Y.-Y.,Shanghai Exit Entry Inspection and Quarantine Bureau | And 5 more authors.
Journal of Chinese Mass Spectrometry Society | Year: 2014

A method for simultaneous detection of 2-alkylcyclobutanones was established by gas chromatography-triple quadrupole mass spectrometry (GC-QqQ-MS/MS). Samples were dissolved by n-hexane, purified by ProElut Silica extraction column. The results show that 2-dodecylcyclobutanone(2-DCB), 2-tetradecylcyclobutanone(2-TCB) are well separated from matrix interference peaks. The peak area against concentration shows good linear relationship in the concentration of 0.005-1.0 mg/L, the linear correlation coefficients (R2) are greater than 0.999. Addition of 0.01, 0.05 and 0.10 mg/kg levels of 2-DCB and 2-TCB in fat-containing function food products, the average recovery ranges from 85.6% to 97.1%, the relative standard deviations (RSDs) are less than 7.0 % (n=6), and the limit of quantification is 5 μg/kg. The method is simple, time-saving, high sensitivity and good stability for real samples analysis, which can provide a theoretical basis for the detection of irradiated markers in the fat-containing function food. ©, 2014, Chinese Society for Mass Spectrometry. All right reserved. Source

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