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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.

Zhang Z.,CAS Research Center for Eco Environmental Sciences | Liu R.,CAS Research Center for Eco Environmental Sciences | Xu D.,Xiamen Entry Exit Inspection and Quarantine Bureau | Liu J.,CAS Research Center for Eco Environmental Sciences
Acta Chimica Sinica | Year: 2012

As a strong carcinogen to humans, acid orange II is forbidden to be added as an additive into foodstuff. Because the foods colored with acid orange II showed stable and colorful appearance, acid orange II is broadly utilized by illegally producers for their low costing. Currently available analytical methods for acid orange II are mainly based on fluorescence and liquid chromatography, which are time-consuming and tedious as acid orange II has to be extracted from the samples before determination. For efficient detection and insurance of food safety, it is urgent to develop fast and low-cost in situ assay methods for field detection of acid orange II on foods. In this study, shell-isolated Au@SiO2 nanoparticles is prepared for detecting acid orange II on food. Gold colloidal solution with good size distribution (50 nm) is prepared using the standard sodium citrate reduction method, followed by coating a thin layer of SiO2 on Au nanoparticle surface. This shell-isolated Au@SiO2 is obtained by the addition of active silica to the gold colloidal solution, with the (3-aminopropyl)trimethoxysilane (APTMS) as the coupling agent at pH 8.5. By regulating the amount of the active silica, the Au@SiO2 with different silica shell thickness is synthesized. Ultraviolet-visible spectroscopy (UV-Vis) and transmission electron microscope (TEM) are employed to characterize the optical property and morphology of the as-synthesized Au@SiO2 nanoparticles. The amount of the active silica added in preparation of the Au@SiO2 is optimized through comparing the surface enhanced Raman scattering (SERS) intensity of acid orange II, using the synthetic Au@SiO2 structure as the SERS substrate. Under the optimized experimental conditions, acid orange II on the Si wafer can be detected at concentrations below 0.17 mg/L. The feasibility of the proposed method for detecting acid orange II in real samples is verified by spreading the Au@SiO2 nanoparticles on the surface of the watermelon seeds stained with acid orange II. Results showed that this novel method is capable of detecting 0.01 mg/g acid orange II stained on the watermelon seeds. This proposed method was applied to assay sunflower seeds and watermelon seeds purchased from local stores. It is expected that this proposed method is applicable for in situ detection of acid orange II on the surface of other food samples. © 2012 Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences.

Peng S.,Chinese Institute of Urban Environment | Yan L.,Xiamen Entry Exit Inspection and Quarantine Bureau | Zhang J.,Chinese Institute of Urban Environment | Shen H.,Chinese Institute of Urban Environment
Chinese Journal of Chromatography (Se Pu) | Year: 2012

Ultra performance liquid chromatography coupled to orthogonal acceleration time-of-flight mass spectrometry was used to study metabolic profiling of L-02 human liver cell exposed to different doses of perfluorooctanoic acid (PFOA) for 72 h. Principle component analysis method was used for group differentiation and biomarker screening. Dose-dependent distribution of the treated samples with different doses could be observed in scores plots obtained under both positive and negative ionization modes. Furthermore, eighteen metabolites were identified as potential biomarkers which were closely related with the toxicity of PFOA. The identified biomarkers included carnitine and acylcarnitines, nucleosides and nucleoside conjugates; amino acids and amino acid conjugates etc. Among them; significant changes of carnitine and its metabolites were observed in the control group and dose groups; which play an important role in fatty acid metabolism. Meanwhile, some genes involved in cholesterol biosynthesis were upregulated dramatically using gene microarray analysis. The disturbance of cholesterol biosynthesis could have adverse impact on fatty acid metabolism, consequently induce the decrease of carnitine and increase of acylcarnitines in treated groups. Additionally, purine metabolism, tricarboxylic acid cycle, glycosphingolipid metabolism and amino acid metabolism may also be involved in the toxic response to PFOA. © 2010 Editorial Office of Chinese Journal of Chromatography, Dalian Institute of Chemical Physics, CAS.

Peng S.,Chinese Institute of Urban Environment | Yan L.,Xiamen Entry Exit Inspection and Quarantine Bureau | Zhang J.,Chinese Institute of Urban Environment | Wang Z.,Chinese Institute of Urban Environment | And 2 more authors.
Journal of Pharmaceutical and Biomedical Analysis | Year: 2013

Perfluorooctanoic acid (PFOA) is one of the most representative perfluorinated compounds and liver is the major organ where PFOA is accumulated. Although the multiple toxicities had been reported, its toxicological profile remained unclear. In this study, a systems toxicology strategy integrating liquid chromatography/mass spectrometry-based metabonomics and transcriptomics analyses was applied for the first time to investigate the effects of PFOA on a representative Chinese normal human liver cell line L-02, with focusing on the metabolic disturbance. Fifteen potential biomarkers were identified on metabolic level and most observations were consistent with the altered levels of gene expression. Our results showed that PFOA induced the perturbations in various metabolic processes in L-02 cells, especially lipid metabolism-related pathways. The up-stream mitochondrial carnitine metabolism was proved to be influenced by PFOA treatment. The specific transformation from carnitine to acylcarnitines, which showed a dose-dependent effect, and the expression level of key genes involved in this pathway were observed to be altered correspondingly. Furthermore, the down-stream cholesterol biosynthesis was directly confirmed to be up-regulated by both increased cholesterol content and elevated expression level of key genes. The PFOA-induced lipid metabolism-related effects in L-02 cells started from the fatty acid catabolism in cytosol, fluctuated to the processes in mitochondria, extended to the cholesterol biosynthesis. Many other metabolic pathways like amino acid metabolism and tricarboxylic acid cycle might also be disturbed. The findings obtained from the systems biological research provide more details about metabolic disorders induced by PFOA in human liver. © 2013 Elsevier B.V.

Zhang J.,Chinese Institute of Urban Environment | Yan L.,Xiamen Entry Exit Inspection and Quarantine Bureau | Tian M.,Chinese Institute of Urban Environment | Huang Q.,Chinese Institute of Urban Environment | And 3 more authors.
Journal of Pharmaceutical and Biomedical Analysis | Year: 2012

Humans undergo simultaneous daily exposure to a multitude of endocrine-disrupting compounds (EDCs). In present study, after combined exposure to endocrine disruptors DEHP and Aroclor 1254 for 12 days, a liquid chromatography/time-of-flight mass spectrometer method combining both reversed-phase (RP) and hydrophilic interaction chromatography (HILIC) separations was carried out to investigate the metabolic responses in mice. The metabolic profiles of endogenous metabolites could differentiate the dose and control groups in both RPLC and HILIC modes. Moreover, the male mice and female mice in different groups could be obviously clustered in their own regions with combined model. Fourteen lysoPCs, PC(18:4/18:1), lysoPE(18:2/0:0), phenylalanine and tryptophan were identified as potential biomarkers for the combined toxicity of DEHP and Aroclor 1254. Different change trends could be observed for the identified lysoPCs, due to their different levels of uptake and metabolism in mice. Moreover, gender-specific differences in several lysoPCs (e.g. lysoPC(18:0), lysoPC(22:6), lysoPC(20:3), and PC(18:4/18:1)) were observed for treated mice. The metabonomic results indicated the combined exposure led to a disturbance of lipid metabolism. The mRNA expressions of PLA2, ACOX1, CPT1, FAS and SCD1 involved in lipid metabolism were investigated. Among them, significant increases of FAS and SCD1 expressions in the liver induced by the exposure could be observed for both male and female mice, contributing to the hepatic lipid accumulation in mice. Besides lipid metabolism, tryptophan metabolism and phenylalanine metabolism may also be involved with the toxic responses to these EDCs. The present study not only improves the understanding of the combined toxicity of phthalates and PCBs but also shows that the metabonomic approach may prove to be a promising technique for the toxicity research of EDCs. © 2012 Elsevier B.V.

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