基于水分活度和水分子流动性的全蝎饮片吸湿特点分析  

Analysis of moisture absorption characteristics of Scorpio based on theory of water activity and water molecular mobility

作　　者：吴钦伟 孟庆民 张尧[3] 漆凤梅 韩童童 刘自强 谌瑞林[1,4,5] 罗晓键 WU Qinwei;MENG Qingmin;ZHANG Yao;QI Fengmei;HAN Tongtong;LIU Ziqiang;CHEN Ruilin;LUO Xiaojian(Jiangxi University of Chinese Medicine,Nanchang 330004,China;Beijing Yanjing Found Biological Technology Company,Beijing 101300,China;National Engineering Research Center for Manufacturing Technology of Solid Preparations of Traditional Chinese Medicine,Nanchang 330004,China;Jiangzhong Pharmaceutical Co.,Ltd.,Nanchang 330004,China;State Key Laboratory for the Modernization of Classical and Famous Prescriptions of Chinese Medicine,Nanchang 330004,China)

机构地区：[1]江西中医药大学,江西南昌330004 [2]北京燕京中发生物技术有限公司,北京101300 [3]中药固体制剂制造技术国家工程研究中心,江西南昌330004 [4]江中药业股份有限公司,江西南昌330004 [5]经典名方现代中药创制全国重点实验室,江西南昌330004

出　　处：《中草药》2025年第6期1926-1934,共9页Chinese Traditional and Herbal Drugs

基　　金：国家自然科学基金项目(81960715);国家自然科学基金项目(82060715);江西省重点研发计划项目(20223BBG71001)。

摘　　要：目的从水分活度(water activity,A_(w))和水分子流动性2个角度,考察中药饮片全蝎的水分吸附特性和热力学性质,为其干燥和储存提供指导。方法通过静态称重法测定全蝎饮片在25、35、45℃下的吸附等温线,采用6种常用的水分吸附数学模型(GAB、Peleg、BET、Smith、Henderson和Halsey)拟合试验数据,确定最佳模型,研究其吸附热力学性质,并结合低场核磁共振(low-field nuclear magnetic resonance,LF-NMR)技术对吸湿平衡状态下全蝎饮片中各状态的水分进行表征,阐明其吸湿特性。结果GAB模型为全蝎饮片吸附的最佳拟合模型,在25、35、45℃条件下其相对安全含水量分别为22.72%、22.35%和23.06%,绝对安全含水量分别为13.21%、12.27%和11.71%。全蝎饮片的净等量吸附热(net equivalent adsorption,q_(st))和微分熵(differential entropy,S_(d))都随着含水量的升高而降低。吉布斯自由能(Gibbs free energy,ΔG)为负,说明吸湿过程是自发的放热反应。样品在不同温度吸湿平衡时,T_(21)、T_(22)、T_(23)、T_(24)均代表样品水分子中质子的峰,其中T_(21)、T_(22)和T_(23)还包含了饮片中醛类、酯类等亲脂性成分中质子的信号。T_(21)随着A_(w)的升高不断右移转化为T_(22)、T_(23)、T_(24),说明饮片中水分子流动性逐渐增大,存在结合水向自由水转化。当A_(w)<0.6时结合水(A_(21)+A_(22))增加趋势并不明显,但当A_(w)>0.6时结合水(A_(21)+A_(22))大幅度增加。结论结合吸附等温线、吸附热力学性质和LF-NMR技术,建议以12%作为全蝎饮片的干燥终点含水量,研究结果可为其他中药饮片安全储藏含水量的确定提供参考。Objective The water adsorption characteristics and thermodynamic properties of Scorpio were investigated from the perspectives of water activity(A_(w))and water molecular fluidity,which provided guidance for their drying and storage.Methods The adsorption isotherms of Scorpio at 25,35,and 45℃were determined by static weighing method.Six commonly used moisture adsorption models(GAB,Peleg,BET,Smith,Henderson and Halsey)were used to fit the experimental data to determine the best model.The thermodynamic properties of the adsorption were studied.Combined with low-field nuclear magnetic resonance(LFNMR),the moisture of each state in the Scorpio under the moisture absorption equilibrium state was characterized to clarify its moisture absorption characteristics.Results The GAB model was the best fitting model for Scorpio adsorption.At 25,35,and 45℃,the relative safe water content was 22.72%,22.35%,and 23.06%,and the absolute safe water content was 13.21%,12.27%,and 11.71%,respectively.The net isosteric heat of sorption(q_(st))and differential entropy(S_(d))of Scorpio decreased with the increase of water content.The Gibbs free energy(ΔG)is negative,indicating that the moisture absorption process is a spontaneous exothermic reaction.When the samples were in moisture absorption equilibrium at different temperatures,T_(21),T_(22),T_(23) and T_(24) all represented the peaks of hydrogen protons in the water molecules of the samples,among which T_(21),T_(22) and T_(23) also contained the signals of hydrogen protons in lipophilic components such as aldehydes and esters in the decoction pieces.With the increase of A_(w),T_(21) continuously shifted to the right and transformed into T_(22),T_(23) and T_(24),indicating that the fluidity of water molecules in the decoction pieces gradually increased,and there was a conversion from bound water to free water.When A_(w)<0.6,bound water(A_(21)+A_(22))did not increase significantly,but When A_(w)>0.6,bound water(A_(21)+A_(22))increased significantly.Conclusion Combined with adsorpti

关 键 词：全蝎饮片 含水量 水分活度 水分子流动性 低场核磁共振 水分吸附特性 热力学性质 净等量吸附热 微分熵 吉布斯自由能 

分 类 号：R283.6[医药卫生—中药学]