Papers by Author: Xiu Hua Zhao

Abstract: Micronized Coenzyme Q₁₀ (CoQ₁₀) is prepared with a rapid expansion of supercritical solution (RESS) process, which does not employ toxic organic solvent. Four factors, namely extraction pressure, extraction temperature, nozzle diameter and precipitation temperature are optimized by a four-level orthogonal array design. The optimum micronization conditions are determined as follows: extraction pressure 25 Mpa, extraction temperature 40°C, nozzle diameter 200 μm, and precipitation temperature 25°C. Under the optimum conditions, micronized CoQ₁₀ with a MPS of 147.9±27.3 nm is obtained. The micronized CoQ₁₀ obtained was characterized by High performance liquid chromatography-mass spectrometry (LC–MS) and High performance liquid chromatography (HPLC) analyses. The results showed that RESS micronization process does not induce degradation of CoQ₁₀ and the obtained CoQ₁₀ particles have higher dissolution rate and solubility compared with unprocessed CoQ₁₀ powder.

Abstract: Epigallocatechin-3-gallate (EGCG), a principal polyphenolic, which is most abundant and active component in tea. It is considered key to these healthful qualities. However, EGCG used in clinical application which is still shortcomings of short half-life and low bioavailability. Chitosan (CS) has been widely used in pharmaceutical and medical areas, particularly for its potential in the development of controlled release drug delivery systems due to its well properties. In this study, we prepared EGCG-loaded chitosan nanoparticles by ionic polymeric method using sodium tripolyphosphate(TPP) as ionic polymeric agent successfully. Results controlled conditions (concentration of CS, 2 mg/mL; pH = 5.4; volume of TPP(0.5 mg/mL), 6.6 mL; amount of EGCG, 15 mg; ionic polymeric time, 24 h at room temperature (0.5 mL/min))volume of TPP(0.5 mg/mL), 6.6 mL; amount of EGCG, 15 mg; ionic polymeric time, 24 h at room temperature (0.5 mL/min)) for entrapment efficiency, loading efficiency, mean particle size and Zeta potential, were found to be 62.3 %, 33.8 %, 141.5 ± 0.4 nm and -31.21 ± 0.54 mV, respectively, and CS-EGCG-NPS have well property of sustained release.

Abstract: In this study, a new method (negative pressure cavitation method, NPC) for metal ions removal from industry waste water has been studied. Under the identical adsorption conditions，we have seen some different effects among static adsorption, shaking adsorption and NPC adsorption. The results are as following: four kind metal ions showed the accordant phenomenon that the sequence of adsorption capacity is NPC adsorption>shaking adsorption>static adsorption. The different metal ions have different improvement of removal ratio. The sequence is Cd>Hg>Pb>Cu. The intercellular pH of absorbed yeast cells increased with the adsorption process from acidic to alkaline. These may suggest that the Candida utilis has certain resistance against heavy metals. The increased pH is also an environment stress response of Candida utilis. So NPC adsorption may have potential values to removal of metal ions.

Abstract: In this study, batch adsorption experiments were carried out for the biosorption of Cd2+ and Pb2+ from aqueous solutions by the invasive alien plant Iva Xanthifolia Nutt (IXN) biomass as adsorbent. Parameters effects such as contact time, pH, initial metal ions concentration, and biomass concentration on the biosorption process were studied. The Langmuir biosorption isotherm was applied to correlate the equilibrium data and fitted quite well. The maximum biosorption capacities for two metal ions were 30.35 mg Cd2+/g and 39.68 mg Pb2+/g, respectively. XRD studies combined with FTIR spectroscopy have also been investigated to represent the biosorption mechanism. Thermodynamic parameters such as enthalpy change (H0), entropy change (S0) and free energy change (G0) were calculated for predicting the nature of biosorption. This study proved that the invasive alien plant IXN can be used as an effective, low-cost and abundant absorbent for the treatment of Cd2+ and Pb2+ containing wastewater.