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Hou J.-B.,Zhejiang Academy of Science and Technology for Inspection and Quarantine | Xie W.,Zhejiang Academy of Science and Technology for Inspection and Quarantine | Li J.,Zhejiang Lead Product Technic Co. | Lu S.,Zhejiang Lead Product Technic Co. | And 2 more authors.
Journal of Chinese Mass Spectrometry Society | Year: 2016

A method of liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed for the determination of five nitrogen-rich adulterants (dicyclanil, dicyandiamide, biuret, cyromazine, melamine) in milk and powdered milk samples. These compounds were potential to be used in economic adulteration to enhance the nitrogen content in milk products. The protein of sample was precipitated, and the extracts were dissolved and distilled with acetonitrile. The supernatant solution was extracted with n-hexane to remove the fat, and then cleaned up with SPE HLB cartridges. The quantitative detection was performed on LC-MS/MS by multiple reaction monitoring (MRM) mode under positive electrospray ionization (ESI+). Isotopes dilution internal standard method (melamine) or external standard method (dicyclanil, dicyandiamide, biuret and cyromazine) was used to determine the residue contents in samples. The limits of quantification (LOQs, S/N=10) are dicyclanil (0.5 μg/kg), dicyandiamide (2.5 μg/kg), biuret (20 μg/kg), cyromazine (5 μg/kg), melamine (15 μg/kg) for milk samples and dicyclanil (8 μg/kg), dicyandiamide (35 μg/kg), biuret (50 μg/kg), cyromazine (40 μg/kg), melamine (50 μg/kg) for powered milk samples. Single-laboratory method validation data are determined, the calibration standard curves concentration are 0, 50, 100, 200, 400 μg/kg and the correlation coefficients are more than 0.991. The average recovery is 72.4%-102.8%, and the relative standard deviation (RSD) is 1.3%-12.3%. The residues of 5 compounds in 55 batches of milk and milk powder samples are determined by LC-MS/MS, and the results are consistent with the national standard method (GB/T 22388-2008). This method is suitable for determination and confirmation of these compounds and provides a convenient, rapid and effective approach to proactively combat economically motivated adulteration in milk and powdered milk sample. © 2016, Editorial Board of Journal of Chinese Mass Spectrometry Society. All right reserved.


Hou J.,Zhejiang Academy of Science and Technology for Inspection and Quarantine | Xie W.,Zhejiang Academy of Science and Technology for Inspection and Quarantine | Chen X.,Zhejiang Academy of Science and Technology for Inspection and Quarantine | Xi J.,Zhejiang Lead Product Technic Co. | And 3 more authors.
Chinese Journal of Chromatography (Se Pu) | Year: 2011

A method of solid phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) for simultaneous determination of 54 drug residues (sulfonamides; nitro-imidazoles, quinolones, macrolides, lincosamides and praziquantel) in honey was developed. The honey samples were diluted by phosphate buffer solution (pH 8) followed by a further cleanup procedure with an Oasis (HLB) SPE column. The detection was carried out by LC-MS/MS, using positive-ion electrospray ionization in multiple reaction monitoring (MRM) mode, with one precursor/two product ion transitions for each compound. Isotope dilution internal standard method or external standard method was used to determine the residue contents with a good linear relationship (r > 0. 992). The limits of quantification (LOQs, S/N > 10) were 1.0 μg/kg for sulfonamides and nitroimidazoles, 2.0 μg/kg for quinolones and lincosamides, 3.0 μg/kg for macrolides, and 0.3 μg/kg for praziquantel. The recovery ranges were from 32.6% to 114% with the relative standard deviations (RSDs) between 1.3% and 28.9%. As a screening method, the developed procedure is suitable for the determination and confirmation of the drug residues in honey samples.


Li B.,Zhejiang University | Su T.,Zhejiang University | Yu R.,Zhejiang University of Technology | Tao Z.,Zhejiang University | And 5 more authors.
African Journal of Microbiology Research | Year: 2010

The inhibitory activities of seven Paenibacillus polymyxa strains and nine Paenibacillus macerans strains against Ralstonia solanacearum strains were examined. Result from this study indicated that the growth of all R. solanacearum strains except strain E406 were inhibited by P. macerans MB02-992 and P. polymyxa MB02-1007, while the other fourteen Paenibacillus strains had no in vitro inhibitory effect against R. solanacearum strains. In addition, suspensions of the two antagonistic bacteria showed antibacterial activities against R. solanacearum under different treatments and reduced the disease incidence and severity of tomato bacterial wilt. Overall, this study clearly demonstrates that antagonistic substances may play an important role in biocontrol of the two antagonistic bacteria. However, antimicrobial activities of P. macerans and P. polymyxa depend on the Paenibacillus strains and the target pathogen. This is the first report about the antibacterial activities of Paenibacillus strains against R. solanacearum strains isolated from different host plants. © 2010 Academic Journals.


Liu H.,Zhejiang Entry Exit Inspection and Quarantine Bureau | Liu H.,Zhejiang Academy of Science and Technology for Inspection and Quarantine | Qian X.,Zhejiang University of Technology | Lu C.,Zhejiang Entry Exit Inspection and Quarantine Bureau | And 5 more authors.
Chinese Journal of Chromatography (Se Pu) | Year: 2013

A high performance liquid chromatographic method was developed for the simultaneous determination of 10 synthetic colorants in cosmetics. The cosmetics were extracted by the ultrasonic technique with tetrahydrofuran (THF), dimethyl sulfoxide (DMSO) and methanol sequentially. Then the extracts were centrifuged for purification and separated on an Eclipse XDB-C18 column (150mm x 4.6mm, 5 μm) with gradient elution by acetonitrile and 0.02mol/L ammonium acetate (pH 4.60, adjusted with acetic acid). A diode array detector was used to determine the colorants with the wavelengths ranging from 417nm to 640nm. The linear relationships of the 10 colorants between the peak areas and the mass concentrations were obtained in the range of 0. 5 -20. 0mg/L (r >0.999). The limits of quantitation ranged from 10 to 20mg/kg. The average recoveries at three concentration levels ranged from 92.9% to 108.8% with the relative standard deviations in the range of 0.5% to 6.1% (n=6). The method is simple, rapid and sensitive. It is suitable for the simultaneous determination of the 10 colorants in the oil cosmetics, cream cosmetics and powder cosmetics.


Wu G.,Zhejiang Academy of Science and Technology for Inspection and Quarantine | Wu G.,Zhejiang University | Zhao S.,Zhejiang Academy of Science and Technology for Inspection and Quarantine | Wu J.,Zhejiang Academy of Science and Technology for Inspection and Quarantine | And 4 more authors.
Chinese Journal of Chromatography (Se Pu) | Year: 2011

A novel method has been developed for the rapid separation and determination of 7 nipagin ester preservatives in leather by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) coupled with gel permeation chromatographic (GPC) clean-up. Nipagin ester preservatives in leather were extracted by ultrasonic extraction with methanol. The extract was dried by a rotavapor and purified by GPC, then redissolved in the solvent of methanol-water (1: 1, v/v). The chromatographic analysis was performed on an Acquity UPLC® BEH C18 column (50 mm × 2.1 mm, 1.7 μm) with a gradient elution of methanol and water as the mobile phases. The analytes were detected by electrospray ionization (ESI) tandem mass spectrometry with multiple reaction monitoring (MRM) in negative ion mode. Good linearity (r > 0.99) was observed between 0.1 and 1.0 mg/L for all the analytes. The recoveries and relative standard deviations (RSDs) were checked by spiking samples with the 7 nipagin ester preservatives at the three levels of 0.5, 1.0 and 3.0 mg/kg. The average recoveries of the 7 nipagin ester preservatives were from (79. 44 ± 5.67)% to (98. 07 ± 9. 50)%. The precision values expressed as RSD ranged from 4.24% to 14.00% (n=6). The limits of detection were 4 - 12 μg/kg and the limits of quantification were 13.2-39.6 μg/kg for the analytes. The method is simple, rapid, sensitive and accurate, and suitable for the quantitative determination and confirmation of 7 nipagin ester preservatives in leather.


Zhu J.,Zhejiang Academy of Science and Technology for Inspection and Quarantine | Wang C.,Zhejiang Academy of Science and Technology for Inspection and Quarantine
Xiandai Huagong/Modern Chemical Industry | Year: 2013

The industrial gas hazards are reviewed. The hazardous classification on the industrial gas package and transport in the United Nations Recommendations on the transport of dangerous goods model regulations (TDG) is researched. On this basis, an correct classification idea of industrial gas samples is proposed. The hazards of industrial gas samples are classified according to the proposed idea and the TDG criterion ultimately.


Zhou Y.,Zhejiang Academy of Science and Technology for Inspection and Quarantine | Xu X.-C.,Zhejiang Academy of Science and Technology for Inspection and Quarantine | Chen Q.-Q.,Zhejiang Academy of Science and Technology for Inspection and Quarantine | Fu X.-P.,Zhejiang University
Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis | Year: 2016

Rapid classification of leather variety means important to product process control, trading process and market surveillance. There is no official detection standard on classification of leather variety for the present. By now the testers use organoleptic method, burning method, chemical dissolution method, microscope method, or combination of them, to give a convincing result. The testers are required to highly sufficiently experienced, and not influenced by subjective factors. It also costs too much time. For the purpose of this research, spectra of five common varieties of leather samples (full-grain leather, split leather, sheep leather, reborn leather and manmade leather) were collected from market. Discriminant analysis combined with pre-processing method, including multiplicative signal correction (MSC), standard normal variate (SNV), first derivative and second derivative were used to classify the spectra above. It shows that the above five varieties of leather overlapped seriously in the same space. But manmade leather can be easily distinguished from the other four leather varieties using rear spectra, with the misclassified percent of 1.2%. The last four leather varieties covered each other partly in the same space, classify of any two of them can reach a lower misclassified percent, about 1.3%~17.9%. Different pre-processing method affected the discriminantion model positively or negatively with no regularity. None of these pre-processing methods was found to give a positive effect in a stable and persistent way. It can be concluded that it is feasible to discriminate the common leather varieties by near infrared Spectroscopy. All of the samples were taken from the finish products in the market (eg, handbag, belt, leather coat), which were processed in different ways (eg. tanning, knurling, dyeing). The different processes of the samples could bring an unforeseeable influence to the model which may be reduced by some method, for example, increasing the number and variety of samples. © 2016, Peking University Press. All right reserved.


Zhang M.Z.,Zhejiang Academy of Science and Technology for Inspection and Quarantine | Zhang X.F.,Zhejiang Academy of Science and Technology for Inspection and Quarantine | Chen X.M.,Zhejiang Academy of Science and Technology for Inspection and Quarantine | Chen X.,Zhejiang Academy of Science and Technology for Inspection and Quarantine | And 2 more authors.
Genetics and Molecular Research | Year: 2015

The enzyme-linked probe hybridization chip utilizes a method based on ligase-hybridizing probe chip technology, with the principle of using thio-primers for protection against enzyme digestion, and using lambda DNA exonuclease to cut multiple PCR products obtained from the sample being tested into single-strand chains for hybridization. The 5′-end amino-labeled probe was fixed onto the aldehyde chip, and hybridized with the single-stranded PCR product, followed by addition of a fluorescent-modified probe that was then enzymatically linked with the adjacent, substrate-bound probe in order to achieve highly specific, parallel, and high-throughput detection. Specificity and sensitivity testing demonstrated that enzyme-linked probe hybridization technology could be applied to the specific detection of eight genetic modification events at the same time, with a sensitivity reaching 0.1% and the achievement of accurate, efficient, and stable results. © FUNPEC-RP.


PubMed | Zhejiang Academy of Science and Technology for Inspection and Quarantine
Type: Journal Article | Journal: Genetics and molecular research : GMR | Year: 2015

The enzyme-linked probe hybridization chip utilizes a method based on ligase-hybridizing probe chip technology, with the principle of using thio-primers for protection against enzyme digestion, and using lambda DNA exonuclease to cut multiple PCR products obtained from the sample being tested into single-strand chains for hybridization. The 5-end amino-labeled probe was fixed onto the aldehyde chip, and hybridized with the single-stranded PCR product, followed by addition of a fluorescent-modified probe that was then enzymatically linked with the adjacent, substrate-bound probe in order to achieve highly specific, parallel, and high-throughput detection. Specificity and sensitivity testing demonstrated that enzyme-linked probe hybridization technology could be applied to the specific detection of eight genetic modification events at the same time, with a sensitivity reaching 0.1% and the achievement of accurate, efficient, and stable results.

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