Synthesis Of Polydivinylbenzene Microspheres And Its Application In Solid - Phase Microextraction

Solid phase microextraction(SPME) preserves the advantages such as high extraction efficiency, solvent-free, simple operation. Meanwhile, porous monodisperse poly(divinylbenzene)(PDVB) microspheres are uniform particle size distribution, high specific surface area, clean surface and good solvent resistance, heat resistance. PDVB can be used as excellent extraction materials.In this paper, porous monodisperse PDVB is synthesized by precipitation polymerization. Optimizing the porogen system, the initiator and monomer concentration, the final synthetic systems consist of initiator AIBN, monomer DVB-80, co-porogen dichloromethane-toluene. Morphology, specific surface area, thermal stability are characterized by scanning electron microspheres, nitrogen adsorption instrument and thermogravimetric analysis machine. The results showed that:(1) the synthesized polymer microspheres had good spherical morphology, uniform particle size. Number average particle diameter was 3.00μm, and the particle size polydispersity index was 1.03.(2) PDVB microspheres had small pores and big specific surface area, and Langmuir specific surface area was 667m2/g.(3) PDVB microspheres had good thermal stability. Decomposition temperature is 375 ℃. The synthesized PDVB microspheres can be used as Solid Phase Microextraction(SPME) coating material because of suitable particle size, specific surface area and temperature resistance.Mixing activated carbon, polymeric microspheres with polydimethylsiloxane(PDMS) respectively, then dip the stainless steel wire into the mixture respectively. After many times, PDMS/DVB/ACAR there-phase SPME fiber is obtained. Outer PDMS/DVB coating is about 114 μm, and inner PDMS/ACAR coating is about 46 μm.The analysis methods to determine residual solvents of powder have been established using PDMS/DVB/ACAR SPME fiber coupling with gas chromatography-mass spectrometer. This method can get good linear range, linear correlation coefficient and recovery. Compared with pharmacopoeia, the limits of detection can achieve 2 to 4 orders of magnitude lower.