Time filter

Source Type

Wu Z.-L.,Guangzhou Quality Supervision and Testing Institute | Chen S.-D.,Guangzhou Quality Supervision and Testing Institute | Lin X.-J.,Guangzhou Quality Supervision and Testing Institute | Mu T.-N.,Haidian District Institute of Products Quality Supervision and Inspection | And 5 more authors.
Modern Food Science and Technology | Year: 2013

A new analytical method was developed for the simultaneous determination of nine fluorescent whitening agents (FWA52, FWA135, FWA184, FWA185, FWA199, FWA367, FWA368, FWA378 and FWA393) in food contact polystyrene materials by high performance liquid chromatography-fluorescence detector (HPLC-FLD). The sample was extracted with trichloromethane, and then cleaned up by precipitating the polymer with methanol and analyzed by HPLC using a Phenomenex Gemini C18 column with methanol - water as the mobile phase for gradient elution. The result indicated that the limits of quantification (LOQs) of nine FAWs were ranged from 1.0~8.0 μg/kg and the linear correlation coefficients (r>0.9992) were obtained within the irrespective linear ranges (0.32~200 μg/L). The recovery rates from spiked samples at the spiking levels of 5~500 μg/kg were ranged from 88.0% to 98.9% with RSD of 2.11~4.34% (n=6). The method was simple, precise and had high recovery rate for determination of FAWs in food contact polystyrene materials.

Yang B.,Chinese Research Academy of Environmental Sciences | Yang B.,Biocontrol | Zhou M.,Haidian District Institute of Products Quality Supervision and Inspection | Zhou L.L.,Chinese Research Academy of Environmental Sciences | And 3 more authors.
Environmental Science and Pollution Research | Year: 2015

Crop germplasms substantially vary in their tolerance for and accumulation of heavy metals, and assessment of this variability plays a significant role in selecting species to use in phytoremediation projects. Here, we examined germplasm-variations in cadmium (Cd), lead (Pb), and zinc (Zn) tolerance and accumulation in ramie (Boehmeria nivea), a fiber crop native to China, which has received little attention. In an 8-week greenhouse test, fourteen germplasms of ramie, among and within deep, middle, and shallow rooted-types, were compared for growth and metal accumulation traits. Results showed that both tolerance and accumulation traits varied across germplasms and rooted-types. The deep rooted-type germplasms produced more biomass and had higher tolerance to metals than the two others. In addition, considerable variations in metal accumulation were observed among plant organs (root, stem, and leaf), rooted-types, germplasms, and metal supply. However, the observed variations in metal tolerance and accumulation among both germplasms and rooted-types were not significant in most cases. In addition to supporting the idea of a certain degree of constitutional metal tolerance for ramie, our results also contribute to deep-rooted germplasms of ramie as a good candidate, rather than middle-/shallow- ones as a least-bad option, for the remediation of multi metal-contaminated soils. © 2015, Springer-Verlag Berlin Heidelberg.

Han W.-Q.,Guangzhou Quality Supervision and Testing Institute | Luo H.-Y.,Guangzhou Quality Supervision and Testing Institute | Xian Y.-P.,Guangzhou Quality Supervision and Testing Institute | Luo D.-H.,Guangzhou Quality Supervision and Testing Institute | And 2 more authors.
Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis | Year: 2015

Sixty-four pieces of shark fin dried products (including real, fake and artificial shark fin products) and real products coated with gelatin were rapidly and nondestructively analyzed by attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR). The characteristic of IR spectrograms among the above four kinds of samples were systematically studied and comparied, the results showed that the spectrograms of the same kind of samples were repeatable, and different kinds of shark fin products presented significant differences in the spectrograms, which mainly manifested as the specific absorption peaks of amido bonds in protein (1650, 1544 cm-1) and skeletal vibration in polysaccharide (1050 cm-1). The spectrograms of real shark fins were characterized by the strong absorption peaks of protein characteristic amide I and II absorbent (1650, 1544 cm-1) and relatively weak C-O-C vibration absorbent (1050 cm-1) owing to the high content of protein and relatively low level of polysaccharide. For fake shark fin products that were molded form by mixing together with the offcut of shark, collagen and other substances, the introduction of non-protein materials leaded to the weaker amido bonds absorbent than real products along with a 30 cm-1 blue shift of amide I absorbent. Opposite to the real sample, the relatively strong absorption peak of polysaccharide (~1047 cm-1) and barely existed amide absorbent were the key features of the spectrogram of artificial samples, which was synthersized by polysaccharide like sodium alginate. Real samples coated with gelatin, the peak strength of protein and polysaccharide were decreased simultaneously when the data collection was taken at the surface of sample, while the spectrogram presented no significant difference to real samples when the data was collected in the section. The results above indicated that by analyzing the characteristic of IR spectrograms and the value range of Apro/Apol collected by ATR-FTIR method could perform the undamaged and rapid identification for shark fins. ©, 2014, Science Press. All right reserved.

Guo X.,Guangzhou Quality Supervision and Testing Institute | Mu T.,Haidian District Institute of Products Quality Supervision and Inspection | Xian Y.,Guangzhou Quality Supervision and Testing Institute | Luo D.,Guangzhou Quality Supervision and Testing Institute | Wang C.,Jinan University
Food Chemistry | Year: 2016

Organophosphate esters (OPEs) are common flame retardants that are used in a wide variety of products. These compounds might migrate into and pollute food products. An analytical method involving an improved approach called the "quick, easy, cheap, effective, rugged, and safe" (QuEChERS) method and ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was developed to simultaneously measure trace levels of nine OPEs in milk powder. Separation of the nine OPEs was optimized on a reversed-phase column within 7 min. The stable isotope tri-n-butyl phosphate-d27 (TBP-d27) was used as an internal standard. This method was validated in terms of its linearity, sensitivity, precision, accuracy and matrix effects. Matrix-matched calibration curves were constructed with 1/x2 as the weighting factor for all of the target compounds resulting in coefficients of regression lines between 0.9938 and 0.9999. The average accuracy was between 73.5% and 110.2%. Intra- and inter-assay precisions for six replicates ranged from 3.9% to 8.9% or below 11%, respectively. The limits of detection (LODs) were in the range of 0.1-0.25 μg/kg, and the limits of quantification (LOQs) were below 1.5 μg/kg. Significant matrix effects have been observed, but suppression or enhancement of the signal was compensated for by the use of an isotopically labeled internal standard. This validated method was successfully applied to determine the concentrations of the OPEs in milk powder. © 2015 Published by Elsevier Ltd.

Xian Y.-P.,Guangzhou Quality Supervision and Testing Institute | Guo X.-D.,Guangzhou Quality Supervision and Testing Institute | Mu T.-N.,Haidian District Institute of Products Quality Supervision and Inspection | Dong H.,Guangzhou Quality Supervision and Testing Institute | And 4 more authors.
Journal of Chinese Mass Spectrometry Society | Year: 2014

A method of liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed for the detection of migration levels of fluorescent whitening agent (FWA) 184 and 393 in food contact plastic container. Through the experiment investigation and analysis, the fat simulant (95% alcohol) was confirmed as soaking solution. The migration rule of analytes in two different migration temperatures (low storage condition of 5℃ and room storage condition of 40℃) and varied migration time were studied by LC-MS/MS, and the corresponding migration equation was established. The results show that the linearity ranges from 0.03 μg/L to 20 μg/L with the correlation coefficients of 0.9992 and 0.9996 for FWA 184 and FWA 393, respectively, and the detection limits are all 0.01 μg/L. The recoveries range from 91.1% to 105.3% and RSD (n=6) range from 2.7% to 6.4% at the spiked levels of 0.03, 0.3 and 3 μg/L. The migration levels of FWA 184 and FWA 393 are increased with the increase of storage temperature and storage time. The method is sensitive, accurate, and suits for determining the migration of FWA184 and FWA393 in food contact plastic container. ©, 2014, Journal of Chinese Mass Spectrometry Society. All right reserved.

Discover hidden collaborations