| A novel binary porogenic agent of Pluronic F127/dodecylamine was used in the fabrication of C8 hybrid monoliths by the two-step acid/base sol-gel transition.Scanning electron microscope images showed that the morphology varied from particle aggregates to co-continuous structure and the sizes of macropore and skeleton decreased when F127 was added.In the meantime,F127 was also helpful for the regulation of the mesopore of the monoliths.As a result,a more fine morphology with a higher surface area was obtained which was more beneficial for small molecules analysis.In addition,the time of sol-gel transition was prolonged about 10 min when reducing the amount of dodecylamine,which provided enough time for filling step and improved the column-to-column reproducibility.The permeability of the C8 hybrid monolithic columns was calculated to be 2.53×10-13 m2 which was still satisfactory compared to the other kinds of monolithic columns.Pressure test was passed in a wide range of flow rate of mobile phase and the van Deemter curves for benzene and toluene were acceptable.The C8 hybrid monolith of the binary porogenic agent had a plate number of 49 000/m which was much higher than that of C8 monolith fabricated by traditional method without Pluronic F127.The performance of the C8 hybrid monoliths was investigated in nanoliquid chromatography-ultraviolet/mass spectrometry（nanoLC-UV/MS） mode.Good peak shapes were obtained in the analysis of polycyclic aromatic hydrocarbons and alkylbenzens.Seven kinds of microcystins and Nod-R were also separated by the C8 hybrid monoliths.As a conclusion,the new C8 hybrid monolithic columns were easier in preparation,more convenient in the control of morphology,higher in column efficiency,and more useful in analysis of small molecules. |