顺铂冻干粉的含量测定

建立了顺铂冻干粉注射液含量测定方法的正相高效液相色谱法,色谱条件为:氨基键合硅胶柱,二甲基甲酰胺为样品溶剂,流动相为乙酸乙酯∶甲醇∶二甲基甲酰胺∶水(25∶16∶5∶5,V/V/V/V),在310 nm检测,流速1.5 mL/min,进样量20μL.该法线性相关,相关系数r为0.999 6,回收率为99.6%～100.3%,精确度为0.21%(n=6),最小检出限为59.2μg/L,符合含量测定要求.     

冷冻干燥中升华界面移动的微CT实验研究

采用微CT扫描仪的扫描成像,图像重构及灰度值分析技术对不同厚度苹果片冷冻干燥的升华过程进行实验观察,分析了界面的移动特性.结果表明,对于单面传导加热的升华干燥过程,物料升华不仅在顶面进行,与搁板接触的底面以及侧面也会有水蒸气逸出.厚物料在升华过程中有一个明显的球形冻结区,升华界面呈三维模式逐渐向物料几何中心收缩.无论物料厚薄,刚开始升华干燥速率比较快,随着干燥层的增厚,升华过程的热质阻力增大,升华速率减慢.     

An approach to enhanced redispersibility of cellulose nanocrystals via freeze-drying their Pickering emulsions

To enhance the redispersibility of dried nanocellulose, cellulose nanocrystal (CNC) cryogels were produced by freeze-drying CNC-stabilized cyclohexane-in-water Pickering emulsions. The CNC cryogels were easily redispersed in water and organic solvents; thus, the approach proposed made it possible to significantly improve CNC redispersibility in aqueous and nonaqueous media.