目的确定体外消化透析法测定朱砂中汞的生物可接受率的实验条件,建立实验流程,并测定朱砂中汞的生物可接受率。方法模拟胃肠消化环境,研究pH、接触时间等因素对朱砂中汞的溶出率及透析时间等对朱砂中汞的生物可接受率的影响规律,确定合...目的确定体外消化透析法测定朱砂中汞的生物可接受率的实验条件,建立实验流程,并测定朱砂中汞的生物可接受率。方法模拟胃肠消化环境,研究pH、接触时间等因素对朱砂中汞的溶出率及透析时间等对朱砂中汞的生物可接受率的影响规律,确定合适模拟条件。结果确定的实验流程模拟条件为:液/固比100,人工胃液pH=1.5,加入0.16%胃蛋白酶1 m l,接触时间100 m in,透析时间100 m in,加入胰液胆盐混合物量为5 m l。在确定的实验条件下,CV-AFS测得水飞朱砂中汞的溶出率为2.5×10-6(n=6,RSD=4.1%),生物可接受率为4.8×10-7(n=6,RSD=3.5%)。结论体外消化透析法可用于测定朱砂中汞的生物可接受率,可为测定含朱砂中成药中汞的生物可接受率提供方法学上的参考。展开更多
Complexes of chitosan with Mn(Ⅱ) were prepared by adding Mn(OAc)2·4H2O to Chitosan solution. IR, elemental analysis and TG analysis were used to character the complex. The results showed that there were coordina...Complexes of chitosan with Mn(Ⅱ) were prepared by adding Mn(OAc)2·4H2O to Chitosan solution. IR, elemental analysis and TG analysis were used to character the complex. The results showed that there were coordinate bands formed. H2O2 was used to degrade chitosan-Mn(Ⅱ) complex, and the molecular distribution of degraded products were investigated after eliminating Mn(Ⅱ) ions using the cation exchange resin column. The result suggested that the Chitosan could be degraded rapidly, the degradation started from higher molecular weight range, the molecular weight distribution of oligosaccharides was much more narrower than that of degradated products from common methods such as hydrolysis, acidic and oxidizing methods. The index of molecular weight distribution was changed with the average degradability. When exceeding 10 oligosaccharides, the smaller of the DP, the smaller of the index.展开更多
The pyrolysis of coconut shell, coconut shell residue and de-ashed coconut shell residue was studied with the thermogravimetric technique, and the pyrolysis kinetics models were established.It was found that for cocon...The pyrolysis of coconut shell, coconut shell residue and de-ashed coconut shell residue was studied with the thermogravimetric technique, and the pyrolysis kinetics models were established.It was found that for coconut shell residue and de-ashed coconut shell residue, pyrolysis mainly occurred between 280—370℃, and there was only a single peak in their DTG curves.But in the case of raw coconut shell, two stages of 230—300℃ and 300—350℃, were involved in the pyrolysis process, which resulted in two peaks in the DTG curve.Apparent activation energies for the pyrolysis of these three materials were estimated, and the difference of apparent activation energies in the low temperature range was more evident than in the high temperature range and the highest reaction rate appeared in the high temperature stage.When used for making activated carbon, coconut shell residue and de-ashed coconut shell residue have more advantages than coconut shell.The pyrolysis temperature is in a narrow range.The pyrolysis process is easy to control and is noted for energy saving.展开更多
文摘目的确定体外消化透析法测定朱砂中汞的生物可接受率的实验条件,建立实验流程,并测定朱砂中汞的生物可接受率。方法模拟胃肠消化环境,研究pH、接触时间等因素对朱砂中汞的溶出率及透析时间等对朱砂中汞的生物可接受率的影响规律,确定合适模拟条件。结果确定的实验流程模拟条件为:液/固比100,人工胃液pH=1.5,加入0.16%胃蛋白酶1 m l,接触时间100 m in,透析时间100 m in,加入胰液胆盐混合物量为5 m l。在确定的实验条件下,CV-AFS测得水飞朱砂中汞的溶出率为2.5×10-6(n=6,RSD=4.1%),生物可接受率为4.8×10-7(n=6,RSD=3.5%)。结论体外消化透析法可用于测定朱砂中汞的生物可接受率,可为测定含朱砂中成药中汞的生物可接受率提供方法学上的参考。
文摘Complexes of chitosan with Mn(Ⅱ) were prepared by adding Mn(OAc)2·4H2O to Chitosan solution. IR, elemental analysis and TG analysis were used to character the complex. The results showed that there were coordinate bands formed. H2O2 was used to degrade chitosan-Mn(Ⅱ) complex, and the molecular distribution of degraded products were investigated after eliminating Mn(Ⅱ) ions using the cation exchange resin column. The result suggested that the Chitosan could be degraded rapidly, the degradation started from higher molecular weight range, the molecular weight distribution of oligosaccharides was much more narrower than that of degradated products from common methods such as hydrolysis, acidic and oxidizing methods. The index of molecular weight distribution was changed with the average degradability. When exceeding 10 oligosaccharides, the smaller of the DP, the smaller of the index.
文摘The pyrolysis of coconut shell, coconut shell residue and de-ashed coconut shell residue was studied with the thermogravimetric technique, and the pyrolysis kinetics models were established.It was found that for coconut shell residue and de-ashed coconut shell residue, pyrolysis mainly occurred between 280—370℃, and there was only a single peak in their DTG curves.But in the case of raw coconut shell, two stages of 230—300℃ and 300—350℃, were involved in the pyrolysis process, which resulted in two peaks in the DTG curve.Apparent activation energies for the pyrolysis of these three materials were estimated, and the difference of apparent activation energies in the low temperature range was more evident than in the high temperature range and the highest reaction rate appeared in the high temperature stage.When used for making activated carbon, coconut shell residue and de-ashed coconut shell residue have more advantages than coconut shell.The pyrolysis temperature is in a narrow range.The pyrolysis process is easy to control and is noted for energy saving.
