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Song J.,Soochow University of China | Song J.,University of Sichuan | Song J.,Chengdu Center for Food and Drug Control | Yang H.,Soochow University of China | And 5 more authors.
Food Chemistry | Year: 2012

AMOZ (3-amino-5-methylmorpholino-2-oxazolidinone) is the metabolite of furaltadone (FTD) which has been banned as a veterinary drug. In this study, three AMOZ derivatives (CPAMOZ) were synthesised and monoclonal antibody against o-nitrobenzaldehyde derivatived AMOZ (NPAMOZ) was produced. The IC50 value of the ELISA for NPAMOZ was 0.17 ng ml-1. The cross reactivity values of the assay with NPAMOZ, CPAMOZ, AMOZ and FTA were 100%, 61.7%, 14.8% and 10.4%, respectively. As no NPAMOZ or CPAMOZ exist if no derivitizing reagent added and FTA is quite unstable, therefore, 14.8% of cross reactivity with AMOZ makes the ELISA capable of directly detecting AMOZ without derivatisation. AMOZ spiked food samples were analysed by ELISA. Recoveries of 72.6-121.2% and intra-assay coefficients of variation of 6.1-17.7% were obtained. The proposed ELISA which also confirmed by HPLC with a good correlation provides an alternative sensitive and fast quantitative method for directly detecting AMOZ in food samples. © 2012 Elsevier Ltd. All rights reserved. Source

Yu X.,Tianjin University of Science and Technology | Deng T.,Tianjin University of Science and Technology | Guo Y.,Tianjin University of Science and Technology | Wang Q.,Chengdu Center for Food and Drug Control
Journal of Analytical Chemistry | Year: 2014

A novel pretreatment system and method for arsenic species continuous analysis of arsenite, arsenate, monomethylarsenate (MMA) and dimethylarsonate (DMA) in freshwater using liquid chromatography combined to hydride generation atomic fluorescence spectrometry (LC-HG-AFS) was designed. Arsenic species of As(III), As(V), MMA and DMA in freshwater samples can be well separated, and the analytical time using the developed method is shortened twice compared to the conventional analytical procedure. Besides, the signal of As(V) can be increased by about 50% and the sensitivity to As(V) has been enhanced. The common coexisting ions in freshwater samples have no interferences with arsenic speciation analysis. A sensitive, low cost and interference-free procedure was developed and successfully applied to arsenic speciation in freshwater with the recoveries of four arsenic species within 89.2-106.2%. LC-HG-AFS has good prospects for speciation analysis of trace and ultra trace elements allowing for hydride generation. © 2014 Pleiades Publishing, Ltd. Source

Sun H.,Sichuan University | Zhang C.,Chengdu Center for Food and Drug Control | Xiang L.,Sichuan University | Pi R.,Sichuan University | And 8 more authors.
Tuberculosis | Year: 2016

Mutations in rpsL, rrs, and gidB are well linked to streptomycin (STR) resistance, some of which are suggested to be potentially associated with Mycobacterium tuberculosis genotypic lineages in certain geographic regions. In this study, we aimed to investigate the mutation characteristics of streptomycin resistance and the relationship between the polymorphism of drug-resistant genes and the lineage of M. tuberculosis isolates in Sichuan, China. A total of 227 M. tuberculosis clinical isolates, including 180 STR-resistant and 47 pan-susceptible isolates, were analyzed for presence of mutations in the rpsL, rrs and gidB loci. Mutation K43R in rpsL was strongly associated with high-level streptomycin resistance (P < 0.01), while mutations in rrs and gidB potentially contributed to low-level resistance (P < 0.05). No general association was exhibited between STR resistance and Beijing genotype, however, in STR-resistant strains, Beijing genotype was significantly correlated with high-level STR resistance, as well as the rpsL mutation K43R (P < 0.01), indicating that Beijing genotype has an evolutionary advantage under streptomycin pressure. Notably, in all isolates of Beijing genotype, a dual mutation E92D (a276c) and A205A (a615g) in gidB was detected, suggesting a highly significant association between this dual mutation and Beijing genotype. © 2015 Elsevier Ltd. All rights reserved. Source

Li S.,Soochow University of China | Song J.,Chengdu Center for Food and Drug Control | Yang H.,Soochow University of China | Cao B.,Soochow University of China | And 2 more authors.
Journal of the Science of Food and Agriculture | Year: 2014

BACKGROUND: Furaltadone (FTD) is a type of nitrofuran and has been banned in many countries as a veterinary drug in food-producing animals owing to its potential carcinogenicity and mutagenicity. FTD is unstable in vivo, rapidly metabolizing to 3-amino-5-methylmorpholino-2-oxazolidinone (AMOZ); thus AMOZ can be used as an indicator for illegal usage of FTD. Usually, for the determination of nitrofurans, the analyte is often a derivative of the metabolite rather than the metabolite itself. In this study, based on the monoclonal antibody (mAb) against AMOZ, a competitive immunochromatographic assay (ICA) using a colloidal gold-mAb probe for rapid and direct detection of AMOZ without a derivatization step in meat and feed samples was developed. RESULTS: The intensity of red color in the test line is inversely related to the analyte concentration and the visual detection limit was found to be 10 ng mL-1. The performance of this assay was simple and convenient because the tedious and time-consuming derivatization step was avoided. The ICA detection was completed within 10 min. The ICA strips could be used for 7 weeks at room temperature without significant loss of activity. The AMOZ spiked samples were detected by ICA and confirmed by enzyme-linked immunosorbent assay. The results of the two methods were in good agreement. CONCLUSION: The proposed ICA provides a feasible tool for simple, sensitive, rapid, convenient and semi-quantitative detection of AMOZ in meat and feed samples on site. To our knowledge, this is the first report of the ICA for direct detection of AMOZ. © 2013 Society of Chemical Industry. Source

Wang C.-K.,CAS Nanjing Institute of Soil Science | Wang C.-K.,University of Chinese Academy of Sciences | Pan X.-Z.,CAS Nanjing Institute of Soil Science | Wang M.,Chengdu Center for Food and Drug Control | And 8 more authors.
Soil Science | Year: 2013

Soil moisture is known to influence the accuracy of predictions of soil organic matter (SOM) by visible and near-infrared diffuse reflectance spectroscopy. However, the predictions may still be sufficient for analysis under specific moisture conditions with acceptable accuracy. Our study aimed to assess the accuracy of predicting SOM under various moisture conditions and to explore the appropriate soil moistures for reliable predictions. In this study, reflectance spectra (380-2,400 nm) of 62 soil samples were measured in the laboratory under various moisture conditions. Partial least-squares regression was used to build the calibration model between the first-derivative spectra and Log (SOM). The results showed that visible and near-infrared method was capable of predicting SOM content under moist conditions and that the prediction was reliable when soil moisture was less than 22% (wt/wt). The results of this study identify the potential to predict SOM under wet soil conditions in areas with loam soils and should help determine the range of soil moisture appropriate in SOM predictions for future research. © 2013 by Lippincott Williams & Wilkins. Source

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