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Xie W.,Zhejiang Entry Exit Inspection and Quarantine Bureau | Han C.,Wenzhou Entry Exit Inspection and Quarantine Bureau | Hou J.,Zhejiang Entry Exit Inspection and Quarantine Bureau | Wang F.,Zhejiang Entry Exit Inspection and Quarantine Bureau | And 2 more authors.
Journal of Separation Science | Year: 2012

An LC-MS/MS method developed for simultaneous analysis of 54 veterinary drug residues of six families in pork meat samples, including sulfanilamide, nitroimidazoles, quinolones, macrolide antibiotics, lincosamides, and praziquantel. The pork meat sample was prepared by extraction with ACN, and clean-up on a C18 SPE cartridge. The sample was separated on a C 8 column and eluted with ACN, methanol, and formic acid. The MS/MS detector is operated in the multiple reaction monitoring mode, acquiring two specific precursor-product ion transitions per target compound. The method showed excellent linearity (R2 ≥ 0.99) and high precision (relative SD, RSD ≤ 19.8%) for all compounds. The method quantification limits of 54 veterinary drug residues were in the range of 0.3-3.0 μg/kg. Recoveries for most analytes based on matrix-matched calibration in matrices were 20.9-121.0%. This method has been successfully applied for analysis of more than 100 pork meat samples from the local market; five of the 54 drugs were detected. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Feng Y.-Y.,Wenzhou University | Dong X.-H.,Wenzhou Entry Exit Inspection and Quarantine Bureau | Hu R.-Y.,Wenzhou University | Ke Q.-Q.,Wenzhou University | Ding B.-Y.,Wenzhou University
Journal of Plant Resources and Environment | Year: 2010

Based on existing biological invasion risk evaluation system, the risk evaluation system with stronger regionality for alien invasive plants in Wenzhou was established according to the investigation results about natural environment and alien invasive plants in Wenzhou, and it was verified by taking alien plant of Acacia mearnsii De Wild, for an example. The evaluation system was composed of six indexes of first grade including domestic and abroad attention degree, geographical distribution, invasive route, dissemination and reproduction way, harmfulness and effect, difficult degree of prevention and dealing treatment, and of fifteen indexes of second grade. And the weight of every index was defined by means of the analytic hierarchy process (AHP), and every index was endowed with different scores (total evaluation score 100) according to different weights, the total score of different indexes was the final evaluation score (R value). Using this evaluation system, the risk of A. mearnsii is evaluated and endowed, and the result shows that the risk evaluation score (R value) of A. mearnsii is 64. It means that the risk level of A. mearnsii in Wenzhou is middle, and a certain monitoring and management should be taken. The risk evaluation system for alien invasive plants in Wenzhou has regional feasibility and can provide a foundation for scientific management of alien invasive plants in Wenzhou. Source


Xie W.,Zhejiang Entry Exit Inspection and Quarantine Bureau | Han C.,Wenzhou Entry Exit Inspection and Quarantine Bureau | Qian Y.,Zhejiang Lead Product Technic Co. | Ding H.,Zhejiang Entry Exit Inspection and Quarantine Bureau | And 2 more authors.
Journal of Chromatography A | Year: 2011

This work reports a new sensitive multi-residue liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for detection, confirmation and quantification of six neonicotinoid pesticides (dinotefuran, thiamethoxam, clothiandin, imidacloprid, acetamiprid and thiacloprid) in agricultural samples (chestnut, shallot, ginger and tea). Activated carbon and HLB solid-phase extraction cartridges were used for cleaning up the extracts. Analysis is performed by LC-MS/MS operated in the multiple reaction monitoring (MRM) mode, acquiring two specific precursor-product ion transitions per target compound. Quantification was carried by the internal standard method with D4-labeled imidacloprid. The method showed excellent linearity (R2≥0.9991) and precision (relative standard deviation, RSD≤8.6%) for all compounds. Limits of quantification (LOQs) were 0.01mgkg-1 for chestnut, shallot, ginger sample and 0.02mgkg-1 for tea sample. The average recoveries, measured at three concentrations levels (0.01mgkg-1, 0.02mgkg-1 and 0.1mgkg-1 for chestnut, shallot, ginger sample, 0.02mgkg-1, 0.04mgkg-1 and 0.2mgkg-1 for tea sample), were in the range 82.1-108.5%. The method was satisfactorily validated for the analysis of 150 agricultural samples (chestnut, shallot, ginger and tea). Imidacloprid and acetamiprid were detected at concentration levels ranging from 0.05 to 3.6mgkg-1. © 2011 Elsevier B.V. Source


Wang C.,Shanghai Entry Exit Inspection and Quarantine Bureau | Zhang Z.,Xiamen Entry Exit Inspection and Quarantine Bureau | Shen Y.,Wenzhou University | Tian Z.,Shanghai Entry Exit Inspection and Quarantine Bureau | And 2 more authors.
Food Chemistry | Year: 2015

For the first time, a rapid, sensitive and accurate liquid chromatography-atmospheric pressure chemical ionisation-tandem mass spectrometry (LC-APCI-MS/MS) method was developed for determination of validamycin A in agricultural food samples (rice, agaric, almond, cabbage, green onion, carrot, tomato, cucumber and spinach). The validamycin A residue was extracted with methanol-water (9/1, v/v) or methanol by vortex, and a HLB solid-phase extraction cartridge was used for cleaning up the extracts. LC-APCI-MS/MS data acquisition was carried out in multiple reaction monitoring (MRM) mode. A series of matrix-matched calibration solutions ranging from 2.5 to 50 ng mL -1 were used to record calibration curve. The limit of quantification (LOQ) was 10 μg kg-1. The average recoveries, measured at three concentrations levels (10.0, 50.0, 100.0 μg kg-1) were in the range 83.5-109.6%. The proposed method offers the best sensitivity and specificity for the routine analysis of validamycin A in agricultural food samples. © 2014 Published by Elsevier Ltd. Source


Hu B.,Shaoxing Entry Exit Inspection and Quarantine Bureau | Dong W.,Shaoxing Entry Exit Inspection and Quarantine Bureau | Xia B.,Wenzhou Entry Exit Inspection and Quarantine Bureau | Song W.,Shaoxing Entry Exit Inspection and Quarantine Bureau | Han C.,Wenzhou Entry Exit Inspection and Quarantine Bureau
Chinese Journal of Chromatography (Se Pu) | Year: 2015

An analytical method for the determination of glucose, fructose, isomaltose, isomaltotriose, maltose, panose and maltotriose was developed by high performance anion exchange chromatography coupled with integrated pulsed amperometric detection. The analysis was performed on a CarboPac™10 column with gradient elution of NaOH-NaOAc as mobile phases. The seven sugars were well separated in less than 26 min and showed good linear correlation coefficients between 0.5 and 50 mg/L. The detection limits (LODs) were 0.1 g/L. The recoveries ranged from 76.5% to 108.4% at different spiked levels. The relative standard deviations were between 3.02% and 8.23%. The established method was applied in determining the seven sugars in different batches of Shaoxing Jiafan rice wines from different manufacturers. The standard fingerprints were established by median values using the obtained results. Similarities of the fingerprints of the samples to the standard were calculated by using angle cosine. The results showed that the similarities of wines from different manufacturers were significantly different, so the method could be used for the identification of rice wines from different manufacturers. Source

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