Preparation Of Urea-formaldehyde Monolithic Column And Its Application For Hydrophilic Solid-phase Microextraction

Solid-phase microextraction(SPME)is a new method for sample pretreatment,which becomes a hotspot in the field of sample pretreatment.SPME materials is the key for SPME.The development of novel,efficient and multi-functional materials for SPME has attracted much attention.As a new kind of SPME material,monolithic column has been widely used for the extraction of trace analytes in complex samples.Hydrophilic SPME is a suitable sample pretreatment method for a large number of polar biologically active substances(or contaminants)in biological samples.Therefore,the development of novel hydrophilic monolithic column for SPME possesses an important scientific significance and application value to enrich and improve the SPME technology.This paper focused on the preparation and application of novel hydrophilic monolithic column for SPME.Main points of this thesis are listed as followed:(1)A novel urea-formaldehyde(UF)hydrophilic monolithic column for SPME was prepared with urea and formaldehyde as polycondensation precursors.The results show that the functional groups of UF solid-phase microextraction monolithic column are-CH2,N-H,C=O,C-N and C-O-C,the most probable pore diameter is 7.3 ?m and the maximum flow rate of 0.6 mL/min.The adsorption capacity of streptomycin,tobramycin and neomycin was 7.36,6.75 and 5.18?g/cm,respectively,(2)The UF monolithic column was used for on-line hydrophilic in-tube SPME and combined with high performance liquid chromatography-evaporative light scattering detection system(HPLC-ELSD),to establish a new method for determination of trace aminoglycoside antibiotics(AGs)in tilapia.Under the optimized conditions,the limits of detection(LODs)of streptomycin,tobramycin and neomycin were discovered in the range of 3.0-5.2 ?g/kg.The recoveries were ranged from 82.1 to 96.7%.(3)The UF monolithic column was used for on-line hydrophilic in-tubeSPME and connected with high performance liquid chromatography-diode array detection system(HPLC-DAD),to establish a new approach for determination of trace methylisothiazolinone and methylchloroisothiazolinone which was added in cosmetics.Under the optimized conditions,the limits of detection(LODs)of two analytes were 5.0 ng/mL and 7.5 ng/mL,respectively.The recoveries were higher than 78.1%.In view of the above,the prepared UF monolithic column has a wide applicability,and it is expected to be a new kind of high-performance hydrophilic solid-phase microextraction material for hydrophobic extraction and impurity purification ability to the polar analysis object in complex matrix.