Studies On Separation Performance And Application Of Novel Gas Chromatography Stationary Phases Based On Cyclotriveratrylene And Truxene Derivatives

The research hotspots of gas chromatography(GC)embodies two aspects:(1)the exploration of new separation materials;(2)the hyphenation of chromatography and mass spectrometry to expand application fields.In this paper,two materials,cyclotriveratrylene(CTV)and thiophene-functionalized truxene(TFT),have been studied as novel stationary phase for GC separation.In addition,a method has been established to investigate the migration regularity of chemical substances in toys based on GC-MS.The main contents are summarized as follows:CTV and its derivatives are a new class of bowl-shape host molecules with rigid electron-rich cavities and have shown distinctive recognition ability for guest compounds.CTV and CTC are reported here for the first time as stationary phases for capillary gas chromatographic separations.They showed weak polarity comparable to the commercial HP-5MS column but exhibited different retention behaviours.CTC appeared serious tailed peaks for esters and haloalkanes due to stronger hydrogen bonding.CTV column exhibited good separation performance for analytes of different types,especially for halogenated aromatic compounds,positional and geometrical isomers.The preferential selectivity of CTV for these analytes primarily originated from their specific ?-? stacking,hydrogen bonding and shape-fitting interactions,which were also confirmed by thermodynamic parameters.Effect of column temperature on retention,separation performance and thermal stability of CTV column were also investigated.CTV column was suggested to be used below 220 °C so as to extend column life.Moreover,CTV column showed good repeatability in terms of run-to-run(RSD<0.1%),day-to-day(RSD<0.33%)and column-to-column(RSD<4.6%).The unique physicochemical features and efficient separation ability for analytes of close properties showed the potential of CTV as a new-type stationary phase in GC as well as separation science.Truxene is a rigid planar heptacyclic polyarene with a Y-shape structure,and can easily be functionalized in three diverging directions in space to serve as an excellent building block for constructing star-shaped oligomers and dendritic materials.In this study,we report a thiophene-functionalized truxene derivative(TFT)coated capillary column for high-resolution GC separations of a series of compounds including the challenging xylene isomers and PCB isomers.The fabricated TFT column exhibited extremely high column efficiency of 4016 plates/m and weak polarity situatedbetween the commercial HP-5MS and DB-35 columns.Different from the commercial columns,TFT column showed preferential retention for halogenated and alkyl benzene analytes.It exhibited high resolving ability for a series of challenging isomers.Up to now,few stationary phases are capable of fulfilling these demanding tasks.Interestingly,its unique retentions for PCBs were found to be related with their dihedral angles and the locations of chlorine atoms.This new finding might help in advancing retention mechanisms and predicting the retentions of analytes of interest.Also,the TFT column performed high thermal stability of up to 360 °C and excellent repeatability.The results of this work demonstrated the potential of truxene-based stationary phase in GC and provided the basis for further investigation of more truxene derivatives in separation science.Residual toxic substances found in toys are a serious threat to children's health;these substances may migrate into the body when toys are handled or sucked by children.However,the migration risk caused by toxic toys is difficult to estimate if the migration regularity of these substances is unknown.In this study,a method was established to investigate the migration regularity of toxic substances,specifically styrene,from acrylonitrile–butadiene–styrene(ABS)toys to saliva and sweat.Two determination methods of residual amount and migration amount were initially developed and then utilized to obtain specific migration data by using a self-made migration device.Migration models were established and then applied to predict the migration behavior of styrene in real toys.The experimental data were consistent with the predicted findings and thus verified the validity of the migration models.Using this approach,we can reasonably predict the migration risk of chemical substances in toys,and provide technical support for the formulation of relevant limited standards and regulatory measures to promote toys safety.There are still many toxic chemical substances in toys.The further research on the migration regularity cannot implement without the high performance chromatographic separation technology as well as various chromatography-mass spectrometry hyphenated techniques.The CTV and TFT columns studied in this paper will be used in the separation and determination of halogenated benzene,xylene isomers,PCB isomers and other substances in toys.