We report studies on the growth of gold nanoparticles by a seed-mediated approach in solution. The synthetic method is adapted from one we published earlier （Ashkarran et al. Appl. Phys. A 2009, 96, 423）. The synthe...We report studies on the growth of gold nanoparticles by a seed-mediated approach in solution. The synthetic method is adapted from one we published earlier （Ashkarran et al. Appl. Phys. A 2009, 96, 423）. The synthesized gold nanoparticles were characterized by X-ray diffraction （XRD）, dynamic light scattering （DLS）, UV-Vis spectroscopy, optical imaging and atomic force microscopy （AFM）. Optical absorption spectroscopy of the prepared samples at 15 A arc current in HAuCI4 solution shows a surface plasmon resonance around 520 nm. It is found that sodium citrate acts as a stabilizer and surface capping agent of the colloidal nanoparticles. The intensity of the plasmonic peak of the prepared gold nanoparticles for 1 minute arc duration gradually increases due to seed mediation for up to 6 hours. The formation time of gold nanoparticles at higher seed concentrations is less than that at lower seed concentrations.展开更多
A simple procedure is described for the HPLC and UV determination of tea saponin in tea seed oil. Determinate was accomplished with UV wavelength detection 550 nm for saponification sample, and HPLC was done under con...A simple procedure is described for the HPLC and UV determination of tea saponin in tea seed oil. Determinate was accomplished with UV wavelength detection 550 nm for saponification sample, and HPLC was done under conditions: C18 analytical column of TC-C18, 4. 6 × 250 mm, column temperature at room temperature, injected sample volume was 10 μL, mobile phase’s methanol, flow-rate 0.8 ml/min and detection wavelength 280 nm.展开更多
文摘We report studies on the growth of gold nanoparticles by a seed-mediated approach in solution. The synthetic method is adapted from one we published earlier （Ashkarran et al. Appl. Phys. A 2009, 96, 423）. The synthesized gold nanoparticles were characterized by X-ray diffraction （XRD）, dynamic light scattering （DLS）, UV-Vis spectroscopy, optical imaging and atomic force microscopy （AFM）. Optical absorption spectroscopy of the prepared samples at 15 A arc current in HAuCI4 solution shows a surface plasmon resonance around 520 nm. It is found that sodium citrate acts as a stabilizer and surface capping agent of the colloidal nanoparticles. The intensity of the plasmonic peak of the prepared gold nanoparticles for 1 minute arc duration gradually increases due to seed mediation for up to 6 hours. The formation time of gold nanoparticles at higher seed concentrations is less than that at lower seed concentrations.
文摘A simple procedure is described for the HPLC and UV determination of tea saponin in tea seed oil. Determinate was accomplished with UV wavelength detection 550 nm for saponification sample, and HPLC was done under conditions: C18 analytical column of TC-C18, 4. 6 × 250 mm, column temperature at room temperature, injected sample volume was 10 μL, mobile phase’s methanol, flow-rate 0.8 ml/min and detection wavelength 280 nm.
