摘要
为充分了解黄芩饮片的吸附与解吸特性,基于热力学基本理论,采用静态称量法,得到黄芩饮片在25,35,45℃,水分活度为0.10~0.85条件下的等温吸附解吸数据,选用8种常用吸湿模型对其进行拟合并对模型进行评价,探讨黄芩饮片的热力学性质。结果表明,Peleg模型是描述黄芩饮片吸附解吸特性的最佳数学模型,并由模型方程计算得到黄芩饮片的绝对安全含水量与相对安全含水量约为9.22%,13.51%;黄芩饮片的净等量吸附热与解吸附热,微分熵与含水量关系密切且均随着含水量的增加而减小;在对黄芩饮片干燥时,可将干基含水率为12.0%判断为干燥的终点;黄芩饮片的吸附与解吸过程均由焓驱动,黄芩饮片的水分吸附与解吸过程均为非自发过程。通过对黄芩饮片等温吸附与解吸规律的考察,可以促进对中药饮片吸附解吸规律的研究,对中药饮片在优选存储条件和干燥加工等方面提供很好的指导作用。
To study the characteristics of adsorption and desorption of Scutellaria baicalensis pieces. On the basic thermodynamic theory,thestatic method was adopted to obtain S. baicalensis pieces＇ isothermal adsorption and desorption data at 25,35,45 ℃,with the water activity between 0. 10 and 0. 85. Eight moisture models were selected to fit the data and then evaluated to determine the thermodynamic properties of S. baicalensis pieces. The results show that,among the eight adsorption models,Peleg fit the best,in which absolutely-safe and the relatively-safe moisture contents of S. baicalensis pieces were around 9. 22% and 13. 51% respectively; the net equivalent heat adsorption and desorption and the differential entropy of S. baicalensis pieces were closely related to moisture content,and decrease within crease of water content; when drying the pieces,12. 0% of moisture content can be taken as the drying end; both of adsorption and desorption processes were driven by enthalpy and non-spontaneous. The study on S. baicalensis pieces＇ isothermal adsorption and desorption rules can help advance studies on adsorption and desorption rules of Chinese herbal pieces,and play a good guiding role in optimizing storage conditions and drying process of Chinese herbal pieces.
出处
《中国中药杂志》
CAS
CSCD
北大核心
2016年第5期830-837,共8页
China Journal of Chinese Materia Medica
基金
国家自然科学基金项目(81260644)
江西中医药大学校级课题(2013ZR0076)
关键词
黄芩
饮片
吸附与解吸附规律
热力学性质
Scutellaria baicalensis
pieces
adsorption and desorption
thermodynamic property
