Pillar[5]arene And Cucurbit[7]uril-polysiloxane As Stationary Phasesfor Gas Chromatography

Macrocyclic compounds with special cavity structure,selective molecular recognition ability and good thermal stability etc.excellent performance,and according to different needs we can design and synthesize various macrocyclic compounds of different sizes of cavity or substituents,but the poor solubility characteristic of macrocyclic compounds restricted their application in the field of chromatography.Polysiloxane has good film-forming property and dispersion ability that can help to solve the above problems of macrocycle compounds.In this research,the separation performance of pillar[5]arene,a new type of macrocyclic compounds,and cucurbit[7]uril,which was difficult to dissolve,as capillary gas chromatographic stationary phases were studied.The research mainly includes the following four parts:Firstly,pillar[5]arene column(MP5 column)was prepared by sol-gel method,and its performance was characterized by the parameters(column efficiency,Golay curve and the McReynolds constant).Its column efficiency reached 4806 plates/m at the optimumed flow rate of 0.55 mL/min,and average polarity was 77,suggesting its weak polarity.Comparison with HP-5MS commercial column revealed the possible retention mechanisms of MP5 column.Secondly,the separation performance of MP5 column was explored by the samples of various types of isomers,and the interaction mechanisms between MP5 column and the analytes were discussed as well.Moreover,the column repeatability,durability and thermal stability were tested,showing good repeatability,durability of over 700 runs and thermal stability of above 240?.Thirdly,the cucurbit[7]uril(CB7)-trifluoropropylmethylpolysiloxane(OV210)binary column(CB7-OVcolumn)was prepared by statically method and its chromatographic parameters(column efficiency,Golay curve and McReynolds constant)were characterized.Its column efficiency was 4661 plates/m at the optimumed flow rate of 0.45 mL/min and average polarity was 166,suggesting its moderate polarity.Fourthly,diverse types of samples and isomers were employed to explore the separation capability and interaction mechanisms of CB7-OV column in comparison with neat CB7 column and OV210 column,respectively.In addition,a commercial DB-35 column was also adopted for comparison.The results demonstrated the advantageous separation performance and different retention mechanisms of the mixed CB7-OV stationary phase over the two neat phases and the DB-35 stationary phase.Furthermore,the CB7-OV column showed good column repeatability and thermal stability.