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Gong A.,Yangzhou University | Gong A.,Yangzhou Polytechnic Institute | Zhu X.,Yangzhou University
Talanta | Year: 2014

In this paper, a simple and efficient ultrasound-assisted ionic liquid dispersive liquid-liquid microextraction (UA IL-DLLME) coupled with high-performance liquid chromatography for the analysis of ulipristal acetate (UPA) was developed. UPA could be easily migrated into 1-octyl-3-methylimidazolium hexafluorophosphate [C8mimPF6] IL phase without dispersive solvent. The research of extraction mechanism showed that hydrophobic interaction force played a key role in the IL-DLLME. Several important parameters affecting the extraction recovery were optimized. Under the optimized conditions, 25-fold enrichment factor was obtained and the limit of detection (LOD) was 6.8 ng mL-1 (tablet) or 9.3 ng mL-1 (serum) at a signal-to-noise ratio of 3. The calibration curve was linear over the range of 0.03-6.0 μg mL-1. The proposed method was successfully applied to the UPA tablets and the real mice serum samples. © 2014 Elsevier B.V. All rights reserved. Source

Gong A.,Yangzhou University | Gong A.,Yangzhou Polytechnic Institute | Ping W.,Yangzhou University | Wang J.,Yangzhou University | Zhu X.,Yangzhou University
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2014

In this paper, carboxymethyl-hydroxypropyl-β-cyclodextrin polymer modified magnetic particles Fe3O4 (CM-HP-β-CDCP-MNPs) were prepared and applied to magnetic solid phase extraction of rutin combined with UV-visible spectrometry detection. The synthesized magnetic particles were characterized by element analysis, Fourier transform infrared spectra, thermal gravimetric analysis, and transmission electron microscopy. Several variables affecting the extraction and desorption of rutin such as pH, the amount of adsorbent, the type and volume of eluent, extraction and desorption time, and temperature were investigated. The maximum adsorption capacity was 67.0 mg g-1 for rutin with the equilibrium time of 30 min at room temperature, and the adsorbent could be reused for 10 times. A calibration curve was linear in the range of 0.05-8.00 μg mL-1 with a relative standard deviation of 2.9% (n = 5, c = 4.0 μg mL-1). The limit of detection was 7.0 ng mL-1. The interaction mechanism between the adsorbent and rutin was also studied. Feasibility of this method was validated by the analysis of rutin tablets and lotus plumule. ©. Source

Chen J.,Yangzhou Polytechnic Institute
Bandaoti Guangdian/Semiconductor Optoelectronics | Year: 2014

A drive module of LED constant current source with the output power of about 50 W was designed, and the load is a LED array consisting of multiple hybrid LED tubes, and the power of each LED is 1 W. By designing and manufacturing of the current-mode flyback converter and constant current control circuit, tests with different loads under different input voltages indicate that the current change laws are similar for each condition. As the load decreases, the output voltage increases but the output current decreases, the output current stability will be up to 4.6%. Under a certain load and the output voltage maintaining at around 47.2 V, the voltage ripple peak-peak value will be approximately 400 mV. The current fluctuation is about 0.05 A, and the output current is stable and reliable, which can be used for power supply of multiple hybrid LED array. Source

Gong A.,Yangzhou University | Gong A.,Yangzhou Polytechnic Institute | Zhu X.,Yangzhou University
Journal of Fluorescence | Year: 2013

A novel spectrofluorimetric method to determine abiraterone acetate and its active metabolite, abiraterone was developed, based on the fact that fluorescence intensity of abiraterone acetate and abiraterone could be enhanced in β-cyclodextrin (β-CD) due to the formation of the inclusion complex. The inclusion interaction of β-CD and abiraterone acetate and the β-cyclodextrin sensitized spectrofluorimetry was examined. The various factors influencing fluorescence were discussed in details. The results showed that under the optimized conditions, the linear range of calibration curve for the determination of biraterone acetate and abiraterone was 0.20 ~ 6.0 μg/mL, and the detection limit (LOD) was 6.8 (r = 0.997) or 6.6 ng/mL (r = 0.996), respectively. No interference was observed from common co-existing substances or pharmaceutical excipient. The method was successfully applied to the analysis of abiraterone acetate in pharmaceutical formulation and abiraterone in human serum/urine. © 2013 Springer Science+Business Media New York. Source

Xu B.,Yangzhou Polytechnic Institute
Materials Research Innovations | Year: 2013

Poly(o-phenylenediamine) (POPD) hollow microspheres with Ag submicrometre particles decorated on both inner and outer surfaces of shells as Ag/POPD hollow hybrids have been successfully fabricated through the reduction of AgNO 3 by ascorbic acid in aqueous solution containing POPD hollow microspheres. Poly(o-phenylenediamine) hollow microspheres with functional amine groups on surfaces of polymer shells are chosen as supporter for Ag particles. Ag/POPD hollow hybrids are characterised by Fourier transform infrared and X-ray diffraction spectroscopy techniques. Formation mechanisms involved have been proposed according to experimental results. Furthermore, catalytic activities of Ag/POPD hollow hybrids towards the reduction of 4-nitrophenol in the presence of NaBH4 have also been investigated. © W. S. Maney & Son Ltd. 2013. Source

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