title: Preparation of stir bars for sorptive extraction using sol-gel technology.
abstract: A sol-gel coating method for the preparation of extractive phase on bars used in sorptive microextraction is described. The extraction phase of poly(dimethylsiloxane) is partially crosslinked with the sol-gel network, and the most part is physically incorporated in the network. Three aging steps at different temperatures are applied to complete the crosslinking process. Thirty-micrometer-thick coating layer is obtained by one coating process. The improved coating shows good thermal stability up to 300 degrees C. Spiked aqueous samples containing n-alkanes, polycyclic aromatic hydrocarbons and organophosphorus pesticides were analyzed by using the sorptive bars and GC. The results demonstrate that it is suitable for both aploar and polar analytes. The detection limit for chrysene is 7.44 ng/L, 0.74 ng/L for C19 and 0.9 ng/L for phorate. The extraction equilibration can be reached in less than 15 min by supersonic extraction with the bars of 30 microm coating layer.
authors.affiliation: Department of Analytical Chemistry and Micro-Instrumentation, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116012, China.
authors.forename: Wenmin
authors.initials: W
authors.lastname: Liu
authors.forename: Hanwen
authors.initials: H
authors.lastname: Wang
authors.forename: Yafeng
authors.initials: Y
authors.lastname: Guan
mesh_terms: D002845:Chromatography / Q000295:instrumentation*; D005782:Gels; D009943:Organophosphorus Compounds / Q000032:analysis; D010575:Pesticides / Q000032:analysis; D011083:Polycyclic Compounds / Q000032:analysis
chemical_list: D005782:Gels; D009943:Organophosphorus Compounds; D010575:Pesticides; D011083:Polycyclic Compounds