Preparation And Separation Performance Of Dehydroabietic Acid Bonded Silica Microspheres

In this paper,a single molecular layer dehydroabietic acid bonded silica microsp Here（Si-DO）was prepared using dehydroabietic acid,a green renewable resource,as raw material,by bonding it to the surface of silica microsp Heres using3-glycidyl ether oxypropyltrimethoxysilane.The successful preparation was verified by FT-IR,NMR,XRD,SEM,TG-DTG,and N₂adsorption analysis.Si-DO was used as a chromatograp Hic stationary p Hase filler and adsorbent,and its separation and adsorption properties were studied.The comparison of Si-DO chromatographic columns was determined using six n-alkylbenzene compounds as probes.The results show that the comparison is closely related to the Partition coefficient of analyte in the stationary and mobile phases,and the temperature and mobile phase affect the Partition coefficient of analyte.When methanol and water are used as mobile phases,the temperature has a significant impact on the comparison of the chromatographic column,and the comparison of the chromatographic column is the lowest at 55°C;When using acetonitrile and water as mobile phases,the mobile phase has a greater impact on the chromatographic column.When the acetonitrile content in the mobile phase is70%,the column becomes disordered with increasing temperature.The comparison has no effect on the thermodynamic enthalpy change,but it will cause the absolute value of thermodynamic entropy change to be smaller and the Gibbs free energy to change from a positive value to a negative value after being included in the comparison calculation.The comparison will significantly affect the accurate calculation of thermodynamic parameters,thereby affecting the correct judgment of chromatographic separation mechanism.The separation performance of Si-DO columns was investigated using SRM870,SRM869b,Engelhardt,and Tanaka standard mixtures,as well as n-alkylbenzene,polycyclic aromatic hydrocarbons,amines,phenols,and carotenoids as analytes.The results show that the stationary phase has good hydrophobicity(k _PB=1.177)and shape selectivity(ɑ_T/O=2.475、ɑ_{TBN/Ba P}=3.641)。The thermodynamic data for the separation of n-alkylbenzene indicate that the separation process is driven by enthalpy.In addition,the repeatability experiment showed that the preparation process of the stationary phase and the chromatographic column had good stability,and the relative standard deviation（RSD）of retention time,peak height,and peak area did not exceed 0.26%,3.54%,and 3.48%,respectively.Density functional theory calculations provide intuitive and quantitative descriptions of various retention mechanisms（including hydrophobic,π-π,hydrogen bonds,and spatial interactions）.The bonding phase of the single molecular layer dehydroabietic acid stationary phase has a"racket"structure,which has unique benzene affinity and strong shape selectivity.Therefore,it has good separation performance for geometric isomers with different molecular shapes.Due to the good hydrophobicity and hydrophobicity selectivity of the stationary phase,dehydroabietic acid bonded silica microspheres（Si-DO-1,Si-DO-2,Si-DO-3,and Si-DO-4）with different bonding amounts were selected as adsorption materials for the adsorption of antibiotics（TC and CIP）in water.By optimizing the adsorption process,Si-DO-4 was selected as the optimal adsorbent,with a solution p H of 6 and an ion concentration of 4.0 mg/L.The quasi second order adsorption kinetics model and Langmuir model are suitable for describing the adsorption process of Si-DO-4 on TC and CIP,with single-layer adsorption being the main adsorption method.The adsorption process of Si-DO-4 for TC and CIP is endothermic and non Spontaneous process.The relatively stable adsorption capacity of Si-DO-4 in five repeated adsorption shows that Si-DO-4 is renewable and has practical application potential.