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Feng W.,Sun Yat Sen University | Feng W.,Guangzhou Fiber Product Testing Institute | Jiang R.,Sun Yat Sen University | Chen B.,Sun Yat Sen University | Ouyang G.,Sun Yat Sen University
Journal of Chromatography A | Year: 2014

A novel fiber-assisted emulsification microextraction (FAEME) method was developed for the determination of eight aromatic amines (AAs) in aqueous samples. In this method, the extraction solvent (100μL chlorobenzene) and the dispersive material (1.0mg kapok fiber fragments) were added successively into the aqueous sample (5.0mL), and then the mixture was emulsified by ultrasound to form the cloudy solution. Phase separation was performed by centrifugation, and the sedimented phase was transferred to micro-inserts with a microsyringe for analysis. All variables involved in the extraction process were identified and optimized. By coupling the analysis with gas chromatography-mass spectrometry (GC-MS), excellent detection limits (0.01-0.2μgL-1), good precision (RSDs, 3.33-6.56%) and linear ranges (0.10-160μgL-1 and 1.0-160μgL-1) were obtained. Compared with the traditional solvent-emulsification method, the extraction recoveries of the proposed method were much higher. Satisfactory recoveries were achieved when the method was used for the analysis of AAs in spiked real water samples. © 2014 Elsevier B.V. Source


Li F.,Donghua University | Luo S.,Donghua University | Luo S.,Guangzhou Fiber Product Testing Institute | Zhang J.,Donghua University | Yu J.,Donghua University
Journal of Thermal Analysis and Calorimetry | Year: 2013

In this paper, studies of the temperature dependence for spherulitic growth of PBST copolyester bearing 70 mol% butylene terephthalate units (named as PBST-70) ranged from 70 to 170 C were first reported based on the Lauritzen-Hoffman secondary nucleation theory. The results showed that maximum spherulitic growth rate of PBST-70 was obtained under crystallization temperature of 90 C, and more perfect spherulites were formed via increasing isothermal crystallization temperature by POM measurement. The classical regime I → II and regime II → III transitions occurred at the temperatures of 150 and 110 C, respectively, using the empirical universal values of U*= 6300 J mol-1 and T ∞ = T g - 30 K. Moreover, the effects of isothermal crystallization temperature on crystal lamellar thickness, thermal and tensile properties of PBST-70 were systematically investigated by small angle X-ray scattering, differential scanning calorimeter, and strength tester. The results indicated that the crystal lamellar thickness increased by increasing isothermal crystallization temperature. The endothermic peak shifted to higher temperature and the tensile properties of PBST-70 were enhanced under higher isothermal crystallization temperature. © 2012 Akadémiai Kiadó, Budapest, Hungary. Source


Chen B.,Sun Yat Sen University | Chen B.,Shenzhen Key Laboratory of Detection Technology for Food Safety | Wu F.-Q.,Shenzhen Key Laboratory of Detection Technology for Food Safety | Wu W.-D.,Shenzhen Key Laboratory of Detection Technology for Food Safety | And 4 more authors.
Microchemical Journal | Year: 2016

A low solvent consumption method was developed to determine 27 different classes of pesticides (including organochlorine pesticide, organophosphorus pesticide, pyrethroid pesticide, fungicide, herbicide and acaricide) in wine using dispersive liquid-liquid microextraction (DLLME). Extraction parameters including type and volume of extraction solvent, type and volume of disperser solvent, salinity, pH, centrifugation time, vortex extraction time and wine volumes were optimized. A mixture of 60. μL chloroform (extraction solvent) and 940. μL acetonitrile (disperser solvent) was injected into 5. mL wine diluent. After shaking and centrifugation, the sedimented phase was transferred into a 200. μL glass insert and determined by gas chromatography-mass spectrometry method (GC-MS). The results demonstrated that the recoveries for all the pesticides spiked at three different levels ranged from 66.7 to 126.1%. The intra-day repeatabilities (RSDs) ranged from 2.0 to 27.2%. The limits of detection ranged from 0.025 to 0.88. μg/L, and the limits of quantification ranged from 0.082 to 2.94. μg/L. The proposed method is very low cost, rapid and convenient, and could be an effective method for monitoring of multi-pesticide in wine. © 2015 Elsevier B.V. Source


Chen B.,Sun Yat Sen University | Chen B.,Shenzhen Key Laboratory of Detection Technology for Food Safety | Jin B.,Shenzhen Key Laboratory of Detection Technology for Food Safety | Jiang R.,Sun Yat Sen University | And 4 more authors.
Analytical Methods | Year: 2014

Dispersive liquid-liquid microextraction (DLLME) coupled with gas chromatography-mass spectrometry (GC-MS) was used to quantify and semi-quantify 304 pesticides and related organic pollutants in surface water. Extraction parameters including types and volumes of extraction solvent, disperser solvent, and the amount of salt addition were optimized to obtain highest recoveries and lowest detection limits. A mixture of 35 μL carbon tetrachloride (extraction solvent) and 1 mL acetone (disperser solvent) was added into 5 mL of water sample. After agitation and centrifugation, 20 μL of the sedimented phase was mixed with 1 μL of the internal standard solution, and 1 μL of the final solution was injected into GC-MS for separation and quantification. The enrichment factors ranging from 42- to 299-fold were obtained for all compounds. The limits of detection ranged from 0.001 to 1.125 μg L-1, and the limits of quantification ranged from 0.003 to 3.75 μg L-1. Of all 304 compounds, 90 compounds showed recoveries from 60% to 120% and RSDs lower than 20%. The proposed method is very low cost, rapid and convenient, and could be an effective method for the monitoring of multiple pesticides in surface water. © The Royal Society of Chemistry 2014. Source


Ji F.,Donghua University | Qiu Y.,Donghua University | Xie J.,Guangzhou Fiber Product Testing Institute | Sun S.,Donghua University
Advanced Materials Research | Year: 2013

It has long been a problem how to objectively evaluate the wet wearing comfortability of fabrics. In this paper a novel testing method was proposed, and an instrument was designed and made. During the testing process, the fabric specimen first got saturated by "sweat" and adhered on the "skin", and then it was separated at due rate from the skin and the in time adhesion force-displacement curve was drawn simultaneously. When the fabric was totally separated from the skin, the maximum adhesion force and adhesion work were measured such as to objectively evaluate the adhesion properties of the fabric specimen. Six different kinds of fabrics were selected and tested. The results show that certain kind of fabric performs characteristic adhesion force-displacement curve, which should be explained through fabric materials and structures. Hence this method is effective in objectively reflecting the wet wearing comfortability of fabrics. © (2013) Trans Tech Publications, Switzerland. Source

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