探讨了N-甘氨酰甘氨酸-MCI-GEL体系固相萃取分离钯的行为。结果表明,MCI-GEL树脂能够吸附钯与N-甘氨酰甘氨酸(Gl C)形成的配合物。探究出了实验的最佳萃取条件:n(Gl C)∶n(Pd(Ⅱ))=1∶1,c(HCl)=0.05 mol/L,V过柱=1 m L/min,钯的萃取率可达99%。实验测定了小柱的萃取容量为4.8 mg/g,以丙酮为洗脱溶剂,2 m L丙酮以1 m L/min的洗脱速度能完全洗脱钯的配合物。对合成试样中的钯进行了分离和测定,效果良好。
All-atom molecular dynamics （MD） simulation and the NMR spectra are used to investigate the interactions in N-glycylglycine aqueous solution. Different types of atoms exhibit different capability in forming hydrogen bonds by the radial distribution function analysis. Some typical dominant aggregates are found in different types of hydrogen bonds by the statistical hydrogen-bonding network. Moreover, temperature-dependent NMR are used to compare with the results of the MD simulations. The chemical shifts of the three hydrogen atoms all decrease with the temperature increasing which reveals that the hydrogen bonds are dominant in the glycylglycine aqueous solution. And the NMR results show agreement with the MD simulations. All-atom MD simulations and NMR spectra are successful in revealing the structures and interactions in the N-glycylglycine-water mixtures.
利用Anton Paar DMA55精密数字密度计测定了288.15,298.15和308.15K甘氨酰甘氨酸在蔗糖-水混合溶剂中的密度,计算了甘氨酰甘氨酸的表观摩尔体积VΦ和极限偏摩尔体积VΦο,得到了其由纯水溶剂转移至混合溶剂中的迁移偏摩尔体积ΔtrsVΦο和理论水化数Nh.根据共球交盖模型,讨论了迁移偏摩尔体积和水化数的变化规律.结果表明,甘氨酰甘氨酸带电中心与蔗糖之间的结构相互作用对其迁移体积有正贡献,且占主导地位.甘氨酰甘氨酸的迁移偏摩尔体积为正值,且随着蔗糖浓度的增大而增大;理论水化数随温度升高、蔗糖浓度的增大而减小;温度升高,极限偏摩尔体积增大,迁移偏摩尔体积变化很小.
