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Wang P.,Key Laboratory of Agro product Safety and Quality | Wang P.,Chinese Academy of Agricultural Sciences | Li Y.,Key Laboratory of Agro product Safety and Quality | Li Y.,Chinese Academy of Agricultural Sciences | And 12 more authors.
Analytical Letters | Year: 2013

A novel, sensitive, and robust method has been developed to detect 9 β2-agonists in porcine urine to monitor illegal use of β2-agonists in swine rearing. The method based on the molecular imprinted polymer (MIP) rapid extraction followed ultra-performance liquid chromatography coupled tandem mass spectrometry (UPLC-MS/MS) detection. The cleaning efficiency of MIP cartridges was demonstrated by comparing with common ion exchange solid phase extraction. The presented method was validated in accordance with the European Commission Decision 2002/657/EC. The linearity, decision limit (CCα), detection capability (CCβ), recovery, precision, robustness, and stability were studied in detail. CCα and CCβ values were from 0.006 ng/mL to 0.03 ng/mL and from 0.02 ng/mL to 0.08 ng/mL, respectively. The mean recoveries and repeatability varied from 68.8% to 94.2% and from 2.8% to 10.1%. The proposed method was applied to test 170 porcine urine samples from the Shaanxi province in China and two urine samples were confirmed as clenbuterol positive and the concentrations of clenbuterol in positive urine samples were about 0.08 ng/mL and 0.1 ng/mL, respectively. The developed method was demonstrated to be more sensitive and robust for the determination of 9 β2-agonists in porcine urine. The method was proven to be simple and easy in operation with high selectivity and good reproducibility. © 2013 Copyright Taylor and Francis Group, LLC.

Wang P.,Key Laboratory of Agro product Safety and Quality | Wang P.,Chinese Academy of Agricultural Sciences | Wang Z.,Beijing Zhifeng Botai Bio technology Co. | Su X.,Key Laboratory of Agro product Safety and Quality | Su X.,Chinese Academy of Agricultural Sciences
Biosensors and Bioelectronics | Year: 2015

A sensitive and quantitative fluorescent multi-component immuno-chromatographic sensor was developed for detection of three β-agonizts: clenbuterol, ractopamine and salbuterol. A competitive immune strategy between antibody conjugated fluorescent beads and β-agonist or their antigens was employed. Each monoclonal antibody specifically recognizes it is corresponding β-agonist in the conjugating zone. The unreacted antibodies were captured by β-agonist antigens immobilized at three test lines in nitrocellulose membrane reaction zone. This enables simultaneous detection of 3 β-agonizts in one single test without any further sample preparation. The test results can be obtained within 10. min. Limit of detections for clenbuterol, ractopamine and salbuterol were 0.10. ng/mL, 0.10. ng/mL and 0.09. ng/mL, respectively. Recoveries ranged from 70.0% to 100.5% and relative standard deviations were below 15%. The assay was evaluated using spiked and real samples and the results were compared with LC-MS/MS. The developed novel assay method provides a low cost, sensitive and rapid approach for on site detection of β-agonizts. © 2014 Elsevier B.V. All rights reserved.

Li T.,Key Laboratory of Agro Product Safety and Quality | She Y.,Chinese Academy of Agricultural Sciences | Wang M.,Key Laboratory of Agro Product Safety and Quality | Liu G.,Key Laboratory of Agro Product Safety and Quality | And 6 more authors.
Food Chemistry | Year: 2015

A simple method based on high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed for the simultaneous determination of organotins - tri-n-butyltin chloride (TBT), triphenyltin chloride (TPT), dibutyltin dichloride (DBT), and diphenyltin dichloride (DPT) - in plastic food packaging. Samples were prepared by ultrasonic extraction with dichloromethane, followed by dissolution in acetonitrile containing 0.1% formic acid, and purification by an MCX column. The extracts were analyzed by LC-MS/MS in multiple reaction monitoring and positive modes with a C18 column; elution was carried out with a gradient of 0.1% formic acid and methanol containing 0.1% formic acid. The limits of detection for TBT, TPT, DBT, and DPT were 0.1, 0.6, 0.8, and 0.3 μg kg-1, respectively. The recovery of organotins in spiked samples ranged from 68% to 113% (relative standard deviation: 0.4-4.2%). The proposed method was successfully employed to identify the target analytes in plastic packaging used for milk and cake. © 2015 Elsevier Ltd.

Wang P.,Key Laboratory of Agro product Safety and Quality | Wang P.,Chinese Academy of Agricultural Sciences | Zhu H.,Capital Normal University | Zhang W.,Key Laboratory of Agro product Safety and Quality | And 6 more authors.
Journal of Separation Science | Year: 2013

A novel molecularly imprinted membrane (MIM) with ractopamine (RAC) as the template and the hydrophilic PVDF membrane as the support was synthesized for the selective absorption of RAC and its structure analogues. The absorption behavior and selectivity of the MIM were studied. The experimental results showed that the MIM had the good selectivity to three β-Agonists including RAC, RIT, and formoterol (FOM) than that of nonimprinted membrane. The adsorption capacity for three compounds was above 1.88 μg/cm2 of per membrane. Based on the clean-up and enrichment of porcine urine samples with the MIM, a sensitive determination method of three β-Agonists in porcine urine samples by using MIM followed ultra performance chromatography coupled MS/MS detection was developed. The LOD and LOQ for RAC, RIT, and FOM were below 0.006 and 0.02 ng/mL, respectively. The mean recoveries, repeatability, and reproducibility of three compounds in porcine urine samples varied from 67.9 to 86.3%, from 3.3 to 10.8%, and from 5.3 to 8.5%, respectively. The presented method was applied to test 50 real porcine urine samples. It was demonstrated to be more sensitive and robust for the determination of RAC, RIT, and FOM in porcine urine. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Zhang Y.-X.,Harbin Institute of Technology | Yang X.,Harbin Institute of Technology | Zou P.,Harbin Institute of Technology | Du P.-F.,Chinese Academy of Agricultural Sciences | And 9 more authors.
International Journal of Environmental Research and Public Health | Year: 2016

Nonylphenol (NP) was quantified using liquid chromatography tandem mass spectrometry (LC-MS/MS) in the urine and plasma of rats treated with 0, 50, and 250 mg/kg/day of NP for four consecutive days. A urinary metabolomic strategy was originally implemented by high performance liquid chromatography time of flight mass spectrometry (HPLC-QTOF-MS) to explore the toxicological effects of NP and determine the overall alterations in the metabolite profiles so as to find potential biomarkers. It is essential to point out that from the observation, the metabolic data were clearly clustered and separated for the three groups. To further identify differentiated metabolites, multivariate analysis, including principal component analysis (PCA), orthogonal partial least-squares discriminant analysis (OPLS-DA), high-resolution MS/MS analysis, as well as searches of Metlin and Massbank databases, were conducted on a series of metabolites between the control and dose groups. Finally, five metabolites, including glycine, glycerophosphocholine, 5-hydroxytryptamine, malonaldehyde (showing an upward trend), and tryptophan (showing a downward trend), were identified as the potential urinary biomarkers of NP-induced toxicity. In order to validate the reliability of these potential biomarkers, an independent validation was performed by using the multiple reaction monitoring (MRM)-based targeted approach. The oxidative stress reflected by urinary 8-oxo-deoxyguanosine (8-oxodG) levels was elevated in individuals highly exposed to NP, supporting the hypothesis that mitochondrial dysfunction was a result of xenoestrogen accumulation. This study reveals a promising approach to find biomarkers to assist researchers in monitoring NP. © 2016 by the authors; licensee MDPI, Basel, Switzerland.

Wang P.,Key Laboratory of Agro product Safety and Quality | Wang P.,Chinese Academy of Agricultural Sciences | Wang X.,Key Laboratory of Agro product Safety and Quality | Wang X.,Chinese Academy of Agricultural Sciences | And 4 more authors.
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences | Year: 2014

A novel and efficient determination method for multi-class compounds including β-agonists, sedatives, nitro-imidazoles and aflatoxins in porcine formula feed based on a fast "one-pot" extraction/multifunction impurity adsorption (MFIA) clean-up procedure has been developed. 23 target analytes belonging to four different class compounds could be determined simultaneously in a single run. Conditions for "one-pot" extraction were studied in detail. Under the optimized conditions, the multi-class compounds in porcine formula feed samples were extracted and purified with methanol contained ammonia and absorbents by one step. The compounds in extracts were purified by using multi types of absorbent based on MFIA in one pot. The multi-walled carbon nanotubes were employed to improved clean-up efficiency. Shield BEH C18 column was used to separate 23 target analytes, followed by tandem mass spectrometry (MS/MS) detection using an electro-spray ionization source in positive mode. Recovery studies were done at three fortification levels. Overall average recoveries of target compounds in porcine formula feed at each levels were >51.6% based on matrix fortified calibration with coefficients of variation from 2.7% to 13.2% (n=6). The limit of determination (LOD) of these compounds in porcine formula feed sample matrix was <5.0μg/kg. This method was successfully applied in screening and confirmation of target drugs in >30 porcine formula feed samples. It was demonstrated that the integration of the MFIA protocol with the MS/MS instrument could serve as a valuable strategy for rapid screening and reliable confirmatory analysis of multi-class compounds in real samples. © 2013 Elsevier B.V.

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